University of Groningen
Exploitation of macrocyclic chemical space by multicomponent reaction (MCR) and their
applications in medicinal chemistry
Abdelraheem, Eman Mahmoud Mohamed
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Publication date: 2018
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Abdelraheem, E. M. M. (2018). Exploitation of macrocyclic chemical space by multicomponent reaction (MCR) and their applications in medicinal chemistry. Rijksuniversiteit Groningen.
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Chapter 6
Versatile Multicomponent Reaction
Macrocycle Synthesis using
α-Isocyano-ω-carboxylic acids
George P. Liao,* Eman M. M. Abdelraheem,* Constantinos G. Neochoritis, Katarzyna Kurpiewska, Justyna Kalinowska-Tłuścik, David C. McGowan and Alexander Dömling
Published in: Org. Lett. 2015, 17, 4980−4983 *Shared the first coauthorship
158 Abstract
The direct macrocycle synthesis of α-isocyano-ω-carboxylic acids via an Ugi multicomponent reaction is introduced. This multicomponent reaction (MCR) protocol differs by being especially short, convergent and versatile, giving access to 12 -22 membered rings.
Introduction
Historically, chemists have always had a special affinity to macrocycles because of their abundance in natural products, their synthetic challenge, and their unusual properties.1 In medicinal chemistry, however, fully synthetic macrocycles are a rather neglected class of compounds presumably due to their complex sequential synthesis and because they have generally not classified as orally bioavailable and drug-like until recent advancements in their synthesis and development. In particular several synthetic macrocycles were recently approved as drugs for unmet medical needs, e.g., to treat hepatitis-C.2 Specifically, macrocycles have a huge potential in targeting modern post-genomic targets which are difficult to address by small molecules such as protein-protein interactions (PPI), currently a therapeutic domain mostly covered by antibodies.3 Hence, macrocycles as intermediates between small molecules and biologics are useful to target flat, large and featureless protein-protein interfaces.4 Recent synthetic advancements in macrocycle synthesis include genetically encoded peptides,5 phage display followed by organic-linker induced cyclization,6 artificially made aminoacylated tRNAs,7 stapled peptides,8 or automated peptoid synthesis,9 to name a few.10 Perhaps, the renaissance of macrocycles is also triggered by the recent introduction of several FDA-approved drugs and clinical stage development drugs, e.g., HCV NS5b polymerase inhibitor TMC647055.4a,11 The latest advancements in macrocycles, however, indicate that macrocycles are an underused compound class in medicinal chemistry. Therefore, methods allowing for rapid and diverse access towards cycles of different size, shape, and function are urgently needed to advance the field.
Macrocycles can also be accessed by multicomponent reactions (MCRs) as elaborated the first time by Failli et al. using N, C-unprotected tri- and hexapeptides to synthesize bioactive cyclic hexapeptides.12 Yudin et al. introduced formylaziridines as bifunctional Ugi starting materials to synthesize spectacular macrocycles.13 Wessjohann et al. used homobifunctional starting materials to synthesize up to 36-membered macrocycles using Ugi reactions.14 Others used Ugi-and Passerini-MCR to assemble macrocycles using a different method, e.g., ring closing metathesis.15 However, amongst the six topologically possible Ugi-reaction promoted direct macrocyclizations (Scheme 1) only one has been realized so far.12
159
Scheme 1. The current state of direct macrocyclizations using U-4CR, ND not described.
Here, we introduce the unprecedented use of α-isocyano-ω-carboxylic acids in macrocycle synthesis via Ugi reaction. Synthetic and structural studies support the scope and usefulness of the approach. The finding is significant as a new versatile and very short synthetic method is added to the arsenal of macrocycle synthesis. Because of the convergent character of MCR, there is a considerable potential to design the 3D shape and therefore biological activity of the macrocycles.
Topologically, there are 6 pathways to form (macro)cycles based on bifunctional starting materials in the classical Ugi-4CR (Scheme 1). We decided to focus here on the cyclisation using bifunctional α-isocyano-ω-carboxylic acids 3 to leverage the most versatile building blocks, primary amine 2 and oxo component 1, for incorporation into the macrocycle 4 (Scheme 2). Therefore, we synthesized six α-isocyano-ω-carboxylic acids of different length (n = 9-15) from their commercial amino acids. Using 1-isocyano-12-dodecanoic acid, which can be accessed in three steps from the commercial amino acid, and together with isobutyraldehyde and benzylamine, we extensively screened different conditions and optimized temperature, solvent, time, additives and concentration (Table 1-3). Methanol as a solvent in 0.01 M dilution, 16 h at rt, was found to be optimal. Surprisingly, the free isocyano carboxylic acid did not work, but we employed the corresponding K-salt with 1.5 equivalents of NH4Cl additive, which worked nicely; therefore, the same conditions were used subsequently. The advantageous effect of additives in the Ugi reaction, although poorly understood, has been reported in the literature.16 We used α-isocyano-ω-carboxylic acids of different length to yield 12-16
160
membered macrocycles after the Ugi ring closure (Scheme 2). Next, we investigated the scope and limitations of the Ugi macrocyclization step regarding the oxo and amine components (4.1-4.4). Side chains with aliphatic, small, bulky and aromatic substituents can be introduced. We also investigated different sized and substituted α-isocyano-ω-carboxylic acids including additional amide and urea motifs (4.5, 4.6).
Scheme 2. Ugi/U-4CR derived macrocycle synthesis pathway and some examples with
macrocyclization yields after purification.
In order to introduce more complexity and flexibility and to better cover the substitution potential of the macrocycle, we investigated the possibility to assemble the overall macrocycle by the union of two orthogonal MCRs, e.g., the linker α-isocyano-ω-carboxylic acids by MCR-1 and the subsequent macro ring closure by MCR-2 (Figure 1).17 MCR of great interest due to its bioisosteric cis-amide character is the Ugi tetrazole reaction (U-T-MCR).18 A general, fast, and efficient synthesis οf these building blocks that do not require more than five sequential reaction steps are depicted in scheme 3 with the used reaction conditions. In the first U-T-MCR, an aldehyde, trityl amine, TMSN3, and a bifunctional ester protected amino acid derived isocyanides are reacted to give α-amino tetrazole 5.
Next, the amine is deprotected to give 6, and an isocyano carboxylic acid is coupled to yield 7. The macrocyclic ring closure by the second MCR (U-4CR) with another equivalent of primary amine and oxo component takes place with the optimized conditions to yield 9. The overall reaction sequence is quite general, some representatives out of a total of 26 macrocycles in ring sizes between 12 and 20 are shown in scheme 3 ( Scheme 3). The substrate scope of the two Ugi MCR variations is great, including aromatic, aliphatic and
161 heteroaromatic oxo components as aldehydes and ketones, and substituted aromatic, or aliphatic amines (9.1-9.6).
Scheme 3. Tetrazole Ugi/U-4CR derived macrocycle synthesis pathway, exemplary structures and
cyclization yields.
Figure 1. A synthetic platform to rapidly access diverse macrocycles by the union of two MCRs.
162
Next, we chose another well-established Ugi MCR to introduce diversity into the macrocycle linker portion: the U-5C-4CR.19 In the U-5C-4CR an unprotected α-amino acid is reacting with an oxo component and an isocyanide in methanol to yield imino -dicarboxylic acid mono-amides, often with very high stereoinduction by the α-amino acid component.19,20 We used diamine-derived mono isocyanide 1121 in order to provide the isocyano-ω-carboxylic acid linker 15, which was macrocyclized with the help of a second MCR, the classical U-4CR, to yield the 21-membered 16.
The overall synthesis exemplified in scheme 4 is not more than five steps and could result in very diverse macrocycles of different size and substitution pattern. We demonstrate the above strategy by using (S)-proline 12 achieving good diastereoselectivity in compound 13. The two diastereomers were separated by chromatography, and the major 13 was reacted further in a sequence involving N-deprotection, coupling, saponification and macrocycle formation via U-4CR to yield 16. In both the tetrazole Ugi/U-4CR and U-5C-4CR/U-4CR strategies (Scheme 3 and 4), the presence of an additive for the final MCR ring closure is necessary.
Scheme 4. Mixed U-5C-4CR/U-4CR strategy derived macrocycle synthesis pathway toward 16.
Several x-ray structures of macrocycles of different size involving different MCR assembly routes and different substituents give some first insight into possible solid-state conformations (Figure 2). The simple rather flat macrocycle 4.5, for example, shows the potential to interact with a flat protein surface often found in protein-protein interactions.
163
Figure 2. Examples of MCR-derived macrocycles in the solid state. Top: macrocycle 4.5 with a
simple unsubstituted linker. Middle: Stereo view of four aligned tetrazole motif macrocycles of different size (20-membered 9.7: cyan, membered 9.1: green, membered 9.8: pink, 16-membered 9.9: purple) as derived from x-ray structures. The ring amide groups are suited to form intermolecular as well as intramolecular hydrogen bonds (below, 9.10) and by virtue of the synthetic approach can be shifted along the macrocycle or hidden. Rendering using PyMol.
The alignment of four different tetrazole moiety containing macrocycles in figure 2 impressively shows the wide special distribution of the macrocycles in the solid phase. Three examples in figure 2 (9.1, 9.9 and 9.10) exemplify the potential of intramolecular hydrogen bonding to potentially stiffen the macrocycle and to also increase hydrophobicity, a mechanism recently reported increasing the bioavailability of macrocycles.22 In particular, the introduction of γ-amino acid linkers such as in 9.1, 9.9 and 9.10 has been recognized to increase passive membrane penetration through intramolecular hydrogen bonding. Another important recent finding is that selective N-alkylation of amide groups in the macrocycle can also increase membrane penetration.23 Classically, this is done by a peptoid approach, while we are using here MCR approach which allows for differential and broad substitution of secondary amides. Clearly, increasing the understanding of folding and confirmation of big cycles as well as rules and strategies to mimic secondary structure elements such as α-helices, β-sheets and loops will help in the rational design of potent and selective macrocyclic drugs for uncommon targets.24
164
The synthesis of macrocycles in all the three followed strategies is based on an Ugi reaction (Scheme 5). Initially, we have the Schiff base formation between the carbonyl and the amine. Afterwards, the α-isocyano-ω-carboxylic anion, which has initially protonated and activated the iminium anion, attacks with the terminal carbon of the isocyanide the iminium anion in a nucleophilic addition. The nitrilium ion that is formed is attacked with a second nucleophilic addition, intramolecular, by the carboxylic acid anion yielding an intermediate which is subjected to a Mumm rearrangement with the transfer of the acyl group from oxygen to nitrogen. All reaction steps are reversible except for the Mumm rearrangement, which drives the whole reaction sequence. In a similar manner, the tetrazole Ugi and the U-5C-4CR are taking place.
Scheme 5. The plausible reaction mechanism for the formation of macrocycles.
In conclusion, we introduce here a general, unprecedented, rapid and highly diverse macrocycle synthesis pathway via MCR, while the final ring closure is performed via Ugi -4CR of α-isocyano-ω-carboxylic acids. The number of steps to generate highly decorated macrocycles of size 12-21 generally does not exceed five sequential steps from simple building blocks. The moderate yields found can be justified by the immense potential this synthetic approach has and the resulting use in the discovery of novel tool compounds and leads. The herein introduced MCR approach allows for the flexible introduction of linker motives which have been described to facilitate passive membrane permeation to potentially increase oral bioavailability. Further macrocyclic scaffold examples of different combinations of MCRs are currently investigated in our laboratory as well as targeted applications for protein-protein interactions and will be reported shortly.
165 General Experimental Procedures:
Optimization conditions for macrocyclization
Table 1. Solvent and additives screening for the macrocyclization reaction. The acid of compound 3.1
was used for the reaction with isobutyraldehyde and benzylamine. The mixtures were allowed to first stir at rt for 16 h, followed by 16 h at 50 oC and finally 16 h at 90 oC. The arrows indicate that a condition was skipped. Reactions were monitored by UPLC. (P = product, D = dimer; xxx = no signal for product found). The reaction highlighted had the cleanest LC chromatogram.
Solvents (Concentration) Additives Rt (ratio P:D) 50 oC (ratio P:D) 90 oC (ratio P:D) H2O + MeOH (0.06 M) 12 M HCl (drops) XXX XXX XXX H2O + MeOH (0.13 M) 1:0 1:1 1:1 MeOH (0.07 M) -> 1:0 1:0 MeOH (0.07 M) NH4Cl -> 1:0 1:0 Toluene (0.44 M) NH4Cl 1:0 1:0 1:1 DMSO (0.15 M) XXX 1:0 1% DMSO (0.15 M) NH4Cl XXX 1:0 XXX ACN (0.06 M) 1:0 1:0 1:0 ACN (0.06 M) NH4Cl 1:0 1:0 1:0 H2O + MeOH (0.04 M) Very little 1:0 1% 1:0 3% H2O + MeOH (0.04 M) NH4Cl Very Little 1:0, 0.1% 1:0, 0.1% TFE (0.06 M) NH4Cl 1:1 1:1 1:1
166
Table 2. Comparison between potassium salt or free acid of compound 3.1 used in the
macrocyclization reaction with isobutyraldehyde and benzylamine. The mixtures were allowed to first stir at rt for 16 h, followed by 16 h at 50 oC. Reactions were monitored by UPLC. (P = product, D = dimer). Conditions Linker carboxylate rt (ratio P:D) 50 oC (ratio P:D) MeOH+NH4Cl (0.08M) K-salt 1:0 Very good and clean UVsignal 1:0 Very good UV signal MeOH+NH4Cl (0.07 M) Acid 1:0 Quite a good signal 1:0 Quite a good signal Toluene+NH4Cl (0.38 M) K-salt 1:0 Small signal 1:0 Small signal Toluene+NH4Cl (0.44 M) Acid 1:0 Small signal 1:0 Small signal
Table 3: Comparison between dilutions for the macrocyclization reaction with the potassium salt of
compound 3.1 and isobutyraldehyde and benzylamine. The mixtures were allowed to stir at rt for 16 h, followed by 16 h at 50 oC. The reactions were monitored by UPLC. (P = product, D = dimer).
Conditions Rt (ratio P:D) 50oC (ratio P:D) Yield MeOH+NH4Cl (0.08 M) 1:1 1:1 12% MeOH+NH4Cl (0.01 M) 6:1 6:1 34%
Procedure and analytical data for α-isocyano-ω-carboxylate esters:
To a solution of the corresponding formamide (1.0 mmol, obtained by stirring the commercially available amino esters at rt for 24 h in ethyl formate, 95 % yield) in pyridine (10 mL), tosyl chloride (1.5 mmol) was added. The reaction was allowed to stir at room temperature for 1.5 h before the mixture was cooled with chipped ice. The resulting mixture was then extracted, dried with MgSO4, filtered and evaporated. The obtained oil was then purified by flash chromatography (Pet ether-Ethyl acetate 1:1) affording compounds 3.
167 Methyl 12-isocyanododecanoate (3.1):
The product was obtained as clear oil (90%, 0.215 g). 1H NMR (400 MHz, CDCl3) δ 3.67 (s, 3 H), 3.38 (tt, J = 6.7 Hz, 2.0 Hz, 2 H), 2.30 (t, J = 7.6 Hz, 2 H), 1.72-1.55 (m, 4H), 1.50-1.38 (m, 2H), 1.29 (bs, 12H). 13C NMR (126 MHz, DMSO) δ 174.0, 155.9, 51.2, 41.5, 33.9, 29.3, 29.2, 29.0, 28.6, 26.2, 24.8 ppm. MS (ESI) m/z calculated [M+H]+: 240.19; found [M+H]+: 240.30.
Methyl 11-isocyanoundecanoate (3.2):
The product was obtained as clear orange oil (99%, 0.223 g). 1H NMR (400 MHz, CDCl3) δ 3.67 (s, 3H), 3.38 (tt, J = 6.7 Hz, 1.9 Hz, 2H), 2.30 (t, J = 7.5 Hz, 2H), 1.72-1.61 (m, 3H), 1.48-1.38 (m, 2H), 1.35-1.25 (m, 12H). 13C NMR (126 MHz, DMSO) δ 174.0, 155.9, 51.3, 41.5, 33.9, 29.2, 29.2, 29.1, 28.6, 26.2, 24.8 ppm. MS (ESI) m/z calculated [M+H]+: 226.17; found [M+H]+: 226.35. Methyl 9-isocyanononanoate (3.3):
The product was obtained as clear brown oil (86%, 0.169 g). 1H NMR (400 MHz, CDCl3) δ 3.67 (s, 3H), 3.38 (tt, J = 6.7 Hz, 1.9 Hz, 2H), 2.31 (t, J = 7.5 Hz, 2H), 1.73-1.61 (m, 4H), 1.45-1.42 (m, 2H), 1.37-1.27 (m, 6H). 13C NMR (126 MHz, DMSO) δ 172.9, 154.5, 50.2, 40.3, 32.8, 27.8, 27.7, 27.2, 25.0, 23.6 ppm. MS (ESI) m/z calculated [M+H]+: 198.14; found [M+H]+: 198.21.
Methyl 8-isocyanooctanoate (3.4):
The product was obtained as clear oil (92%, 0.168 g). 1H NMR (400 MHz, CDCl3) δ 3.67 (s, 3H), 3.38 (tt, J = 6.6 Hz, 2.0 Hz, 2H), 2.31 (t, J = 7.4 Hz, 2H), 1.76-1.59 (m, 4H), 1.51-1.40 (m, 2H), 1.39-1.30 (m, 4H). 13C NMR (126 MHz, DMSO) δ 174.6, 155.9, 51.7, 41.7, 34.2, 29.2, 29.1, 28.6, 26.4, 25.0 ppm. MS (ESI) m/z calculated [M+H]+: 184.13; found [M+H]+: 184.29.
Methyl 5-((4-isocyanobutyl)amino)-5-oxopentanoate (3.5):
The product was obtained as clear oil (85%, 0.192 g). 1H NMR (400 MHz, CDCl3) δ 5.65 (bs, 1H), 3.68 (s, 3H), 3.48-3.40 (m, 2H), 3.31 (q, J = 6.4 Hz, 2H), 2.38 (t, J = 7.2 Hz, 2H), 2.28-2.19 (m, 2H), 2.00-1.92 (m, 2H), 1.75-1.62 (m, 4H). 13C NMR (126 MHz, DMSO) δ 173.4, 172.9, 155.3, 60.4, 51.6, 33.3, 27.7, 25.0, 20.1 ppm. MS (ESI) m/z calculated [M+H]+: 227.13; found [M+H]+: 227.87.
Methyl 4-(3-(5-isocyanopentyl)ureido)butanoate (3.6):
The product was obtained as yellow oil (42%, 0.101 g). 1H NMR (400 MHz, CDCl3) δ 4.63 (bs, 2H), 3.68 (s, 3H), 3.40 (tt, J = 6.5 Hz, 1.9 Hz, 2H), 3.23-3.17 (m, 4H), 2.38 (t, J = 7.0 Hz, 2H), 1.86-1.79 (m, 2H), 1.77-1.66 (m, 4H), 1.61-1.44 (m, 4H). 13C NMR (126 MHz, DMSO) δ 173.4, 173.2, 155.1, 51.4, 43.6, 40.5, 31.3, 29.9, 28.6, 26.4, 24.5 ppm. MS (ESI) m/z calculated [M+H]+: 242.14; found [M+H]+: 242.60.
168
Procedure and analytical data for N-trityl protected α-aminotetrazoles:
Aldehyde (1.5 mmol) and tritylamine (1.0 mmol) were suspended in MeOH (1 mL) in a sealed vial with a magnetic stirring bar. The reaction was heated at 100 oC for 15 minutes using microwave irradiation. Then isocyanide (1.0 mmol) and azidotrimethylsilane (1.0 mmol) were added to the reaction mixture and further heated at 100 oC for 15 minutes using microwave irradiation. The solvent was removed under reduced pressure and the residue was purified using flash chromatography (Pet ether-Ethyl acetate 1:1).
Methyl 4-(5-((tritylamino)methyl)-1H-tetrazol-1-yl)butanoate (5.1):
The product was obtained as a white solid (96%, 0.424 g). 1H NMR (500 MHz, DMSO) δ 7.43 (d, J = 8.2 Hz, 6H), 7.33 (t, J = 7.7 Hz, 6H), 7.23 (t, J = 7.3 Hz, 3H), 4.36 (t, J = 7.1 Hz, 2H), 3.79 (t, J = 7.5 Hz, 1H), 3.55 (d, J = 9.3 Hz, 5H), 2.35 (t, J = 7.3 Hz, 2H), 2.08-1.99 (m, 2H). 13C NMR (126 MHz, DMSO) δ 172.1, 153.6, 144.8, 128.3, 128.2, 127.6, 126.2, 70.7, 51.2, 51.1, 45.9, 36.4, 29.9, 24.0 ppm. MS (ESI) m/z calculated [M+H]+: 442.52; found [M+Na]+: 464.50. Methyl 6-(5-((tritylamino)methyl)-1H-tetrazol-1-yl) hexanoate (5.2):
The product was obtained as a white solid (78%, 0.366 g). 1H NMR (500 MHz, DMSO) δ 7.43 (d, J = 7.7 Hz, 6H), 7.33 (t, J = 7.7 Hz, 6H), 7.23 (t, J = 7.3 Hz, 3H), 4.30 (t, J = 7.3 Hz, 2H), 3.81 (t, J = 7.5 Hz, 1H), 3.55 (d, J = 9.5 Hz, 5H), 2.27 (t, J = 7.4 Hz, 2H), 1.79-1.71 (m, 2H), 1.53-1.46 (m, 2H), 1.22 (t, J = 7.8 Hz, 2H). 13C NMR (126 MHz, DMSO) δ 173.4, 153.9, 145.2, 128.7, 128.6, 128.1, 126.7, 71.1, 51.4, 46.9, 36.9, 33.2, 28.9, 25.5, 24.0. MS (ESI) m/z calculated [M+H]+:469.58; found [M+Na]+: 492.37.
Methyl 4-(5-(3-phenyl-1-(tritylamino)propyl)-1H-tetrazol-1-yl)butanoate (5.3): The product was obtained as a white solid (59%, 0.321 g). 1H NMR (500 MHz, CDCl3) δ 7.39 (d, J = 7.5 Hz, 6H), 7.24 (t, J = 7.5 Hz, 3H), 7.19 (d, J = 7.8 Hz, 6H), 7.14 (dd, J = 5.7 Hz, 3.7, 3H), 7.04 (d, J = 7.3 Hz, 2H), 4.05-4.00 (m, 1H), 3.79-3.73 (m, 1H), 3.70-3.64 (m, 1H), 3.61 (s, 3H), 2.53-2.49 (m, 1H), 2.47-2.42 (m, 1H), 2.32-2.27 (m, 2H), 2.23-2.19 (m, 1H), 1.99-1.95 (m, 2H), 1.95-1.89 (m, 1H). 13C NMR (126 MHz, CDCl3) δ 172.5, 157.3, 145.2, 140.7, 128.6, 128.5, 128.2, 127.9, 126.8, 126.1, 71.6, 51.8, 47.9, 46.0, 38.8, 31.1, 30.4, 24.1. MS (ESI) m/z calculated [M+H]+: 546.67; found [M+Na]+: 568.26.
Methyl 6-(5-(3-phenyl-1-(tritylamino)propyl)-1H-tetrazol-1-yl)hexanoate (5.4): The product was obtained as a white solid (59%, 0.338 g). 1H NMR (500 MHz, CDCl3) δ 7.39 (d, J = 7.6 Hz, 6H), 7.28-7.22 (m, 4H), 7.21-7.18 (m, 5H), 7.16 (d, J = 7.0 Hz, 3H), 7.02 (d, J = 7.4 Hz, 2H), 3.99 -3.94 (m, 1H), 3.65 (s, 3H), 3.62-3.58 (m, 1H), 3.53- 3.44 (m, 1H), 3.02 (d, J = 8.5 Hz, 1H), 2.60-2.50 (m, 1H), 2.452.37 (m, 1H), 2.26 (t, J = 7.3 Hz, 2H), 2.25 -2.20 (m, 1H), 1.95-1.92 (m, 1H), 1.67-1.63 (m, 2H), 1.59-1.54
169 (m, 2H), 1.27-1.22 (m, 2H). 13C NMR (126 MHz, CDCl3) δ 173.7, 157.1, 145.3, 140.7, 128.6, 128.2, 128.2, 127.9, 126.8, 126.2, 71.7, 51.6, 47.8, 46.9, 38.9, 33.6, 31.0, 28.8, 26.1, 24.2. MS (ESI) m/z calculated [M+H]+: 574.73; found [M+Na]+: 596.73.
Procedure and analytical data for the U-5C-4CR:
To a stirred solution of (S)-proline (2.0 mmol) in MeOH (2 mL), tert-butyl-(4-isocyanobutyl)carbamate[1] {2.0 mmol, obtained by the dehydration of the corresponding formamide[2] under standard conditions, white solid, 95% yield; 1H NMR (CDCl3, 500 MHz) δ 8.15 (s, 1H), 6.48 (bs, 1H, NH), 4.87 (bs, 1H, NH), 3.32 -3.31 (m, 2H), 3.14-3.13 (m, 2H), 1.57-1.55 (m, 4H), 1.44 (s, 9H) ppm; 13C NMR (CDCl3, 126 MHz) δ 165.0, 161.6, 156.3, 40.2, 37.9, 28.5, 27.6, 26.7 ppm} and benzaldehyde (2.0 mmol) were added. The reaction mixture was stirred for 48 h at rt. Afterwards, the solvent evaporated and the reaction mixture purified by column chromatography (Pet ether-Ethyl acetate 1:1) affording mixture of the diastereomers 13a and 13b in 45% yield and dr 70:30.
(S)-Methyl 1-(2-((4-((tert-butoxycarbonyl)amino) butyl)amino)-2-oxo-1-phenylethyl)-pyrrolidine-2-carboxylate (13a):
The product was obtained as a yellow oil, major isomer; 1H NMR (CDCl3, 500 MHz) δ 8.01 (t, J = 5 Hz, 1H, NH), 7.31-7.24 (m, 5H), 4.80 (bs, 1H, NH), 4.21 (s, 1H), 3.48 (s, 3H), 3.33 -3.23 (m, 4H), 3.13 (bs, 2H), 2.72-2.70 (m, 1H), 2.69-2.62 (m, 1H), 2.04-1.99 (m, 1H), 1.91-1.79 (m, 3H), 1.59-1.58 (m, 2H), 1.53-1.52 (m, 2H), 1.44 (s, 9H) ppm; 13C NMR (CDCl3, 126 MHz) δ 176.2, 172.0, 156.1, 137.1, 129.1, 128.5, 128.3, 73.5, 61.8, 54.5, 51.7, 40.1, 38.8, 30.7, 28.4, 27.4, 26.9, 24.3 ppm. MS (ESI) m/z: calculated, [M+H]+: 434.26; found: 434.29.
(S)-Methyl 1-(2-((4-((tert-butoxycarbonyl)amino)butyl) amino)-2-oxo-1-phenylethyl)-pyrrolidine-2-carboxylate (13b):
The product was obtained as ayellow oil, minor isomer; 1H NMR (CDCl3, 500 MHz) δ 7.56-7.53 (m, 1H, NH), 7.34-7.28 (m, 5H), 4.67 (bs, 1H), 4.35 (s, 1H), 3.66 (s, 3H), 3.52 (dd, J = 5, 0.5 Hz, 1H), 3.32-3.23 (m, 2H), 3.12-3.11 (m, 2H), 2.93-2.89 (m, 1H), 2.53-2.48 (m, 1H), 2.10-2.06 (m, 1H), 1.92-1.90 (m, 1H), 1.86-1.80 (m, 1H), 1.77-1.73 (m, 1H), 1.55-1.44 (m, 4H), 1.42 (s, 9H) ppm; 13 C NMR (CDCl3, 126 MHz) δ 176.2, 172.0, 156.1, 137.1, 129.1, 128.5, 128.3, 73.5, 61.8, 54.5, 51.7, 40.1, 38.8, 30.7, 28.4, 27.4, 26.9, 24.3 ppm. MS (ESI) m/z: calculated, [M+H]+: 434.26; found: 434.29.
Procedure and analytical data for N-deprotected α-aminotetrazoles and the U-5C-4CR adduct:
N-trityl protected α-aminotetrazole (0.5 mmol) was dissolved in dichloromethane (2.5
mL) in a vial with a magnetic stirring bar. Trifluoroacetic acid (1.0 mmol, 77 μL) was added dropwise. The reaction developed for 1 min. The reaction mixture was purified using a silica pad wetted with heptane: EtOAc (1:1). The side product was washed out with heptane: EtOAc (1:1). The N-deprotected α-aminotetrazole was collected with methanol:
170
CH2Cl2 (1:1). The solvent was removed under reduced pressure which gave the pure product.
Methyl 4-(5-(aminomethyl)-1H-tetrazol-1-yl)butanoate (6.1):
The product was obtained as a white solid (80%, 0.079 g). 1H NMR (500 MHz, DMSO) δ 8.71 (s, 3H), 4.49 (s, 2H), 4.44 (t, J = 7.2 Hz, 2H), 3.59 (s, 3H), 2.42 (t, J = 7.3 Hz, 2H), 2.14-2.01 (m, 2H).13C NMR (126 MHz, DMSO) δ 171.9, 149.8, 51.3, 45.5, 31.2, 29.4, 23.5 ppm. MS (ESI) m/z calculated [M+H]+: 200.21; found [M-H]+: 198.18.
Methyl 6-(5-(aminomethyl)-1H-tetrazol-1-yl)hexanoate (6.2):
The product was obtained as a white solid (88%, 0.099 g). 1H NMR (500 MHz, DMSO) δ 8.74 (s, 3H), 4.51 (s, 2H), 4.39 (t, J = 7.3 Hz, 2H), 3.58 (s, 3H), 2.31 (t, J = 7.4 Hz, 2H), 1.89-1.77 (m, 2H), 1.61-1.50 (m, 2H), 1.29 (t, J = 7.6 Hz, 2H).13C NMR (126 MHz, DMSO) δ 172.9, 150.0, 46.5, 32.7, 31.5, 28.1, 24.9, 23.5 ppm. MS (ESI) m/z calculated [M+H]+:228.26; found [M-H]+: 226.23.
Methyl 4-(5-(1-amino-3-phenylpropyl)-1H-tetrazol-1-yl)butanoate (6.3):
The product was obtained as a white solid (75%, 0.113 g). 1H NMR (500 MHz, DMSO) δ 9.07 (bs, 2H), 7.28 (t, J = 7.5 Hz, 2H), 7.17 (t, J = 9.2 Hz, 3H), 4.98 (t, J = 6.7 Hz, 1H), 4.49-4.41 (m, 2H), 3.59 (s, 3H), 2.72-2.62 (m, 1H), 2.60-2.51 (m, 1H), 2.44 (t, J = 7.3 Hz, 2H), 2.38-2.23 (m, 2H), 2.08 - 1.98 (m, 2H). 13C NMR (126 MHz, DMSO) δ 173.0, 153.2, 140.4, 129.0, 128.6, 126.7, 51.9, 46.7, 43.8, 34.5, 30.5, 24.8 ppm. MS (ESI) m/z calculated [M+H]+: 304.36; found [M+Na]+: 326.23.
Methyl 6-(5-(1-amino-3-phenylpropyl)-1H-tetrazol-1-yl)hexanoate (6.4):
The product was obtained as a white solid (67%, 0.111 g). 1H NMR (500 MHz, DMSO) δ 9.01 (bs, 2H), 7.47 (d, J = 7.5 Hz, 1H), 7.30 (t, J = 7.0 Hz, 2H), 7.21 (t, J = 7.5 Hz, 1H), 7.17 (d, J = 7.0 Hz, 2H), 7.12 (d, J = 6.5 Hz, 1H), 4.98 (t, J = 7.0, 1H), 4.38-4.37 (m, 2H), 3.58 (s, 3H), 2.69-2.66 (m, 1H), 2.65-2.63 (m, 1H), 2.33 (t, J = 5.0 Hz, 4H), 1.83-1.80 (m, 2H), 1.58-1.55 (m, 2H), 1.34-1.27 (m, 2H). 13C NMR (126 MHz, DMSO) δ 174.0, 153.1, 140.2, 129.1, 128.6, 126.9, 51.8, 47.5, 43.9, 34.6, 33.5, 30.7, 29.1, 25.7, 24.3 ppm. MS (ESI) m/z calculated [M+H]+: 332.41; found [M+Na]+: 354.27.
(2S)-methyl 1-(2-((4-aminobutyl)amino)-2-oxo-1-phenylethyl)pyrrolidine-2-carboxy-late (14):
The product was obtained as yellow oil (90% yield, 0.152 g). 1H NMR (MeOH-d4, 500 MHz) δ 8.62 (bs, 1H), 7.52-7.44 (m, 5H), 5.22 (s, 1H), 4.25 (s, 1H), 3.68 (s, 3H), 3.47-3.20 (m, 5H), 2.85-2.83 (m, 2H), 2.49-2.44 (m, 1H), 2.15-2.04 (m, 3H), 1.55-1.50 (m, 5H) ppm; 13C NMR (MeOH-d4, 126 MHz) δ 171.0, 168.6, 162.7, 132.0, 132.2, 130.8, 71.6, 67.2, 40.3, 30.0, 27.1, 25.9, 24.1 ppm.
171 Procedure and analytical data for the coupling reactions:
A suspension of N-deprotected α-aminotetrazole derivatives (1.0 mmol), potassium isocyanide derivatives (1.2 mmol), and triethylamine (1.0 mmol) in CH3CN was stirred for 10 min under ice cooling, then HOBt (1.0 mmol) and DCC (1.0 mmol) were added to the mixture, the reaction mixture was stirred for 48 hr. The insoluble materials were filtered off and the filtrate was evaporated. The residue was purified by column chromatography (Pet ether-Ethyl acetate 1:4).
Methyl 4-(5-((4-isocyanobutanamido)methyl)-1H-tetrazol-1-yl)butanoate (7.1): The product was obtained as a yellow oil (64%, 0.188 g). 1H NMR (500 MHz, CDCl3) δ 7.16 (bs, 1H), 4.69 (d, J = 5.9 Hz, 2H), 4.49 (t, J = 7.1 Hz, 2H), 3.64 (s, 3H), 3.45 (t, J = 6.3 Hz, 2H), 2.49-2.34 (m, 4H), 2.26-2.15 (m, 2H), 2.03-1.92 (m, 2H). 13C NMR (126 MHz, CDCl3) δ 172.7, 171.8, 156.8, 152.4, 52.0, 46.6, 40.9, 32.0, 31.8, 30.3, 24.7, 24.4 ppm. MS (ESI) m/z calculated [M+H]+: 295.15; found [M+Na]+: 317.19.
Methyl 6-(5-((4-isocyanobutanamido)methyl)-1H-tetrazol-1-yl)hexanoate (7.2): The product was obtained as a yellow oil (75%, 0.241 g). 1H NMR (500 MHz, CDCl3) δ 7.50 (bs, 1H), 4.73 (d, J = 5.8 Hz, 2H), 4.46 (t, J = 7.3 Hz, 2H), 3.68 (s, 3H), 3.51 (t, J = 6.3 Hz, 2H), 2.50 (t, J = 7.1 Hz, 2H), 2.35 (t, J = 7.3 Hz, 2H), 2.09-2.00 (m, 2H), 1.99-1.92 (m, 2H), 1.72-1.66 (m, 2H), 1.45-1.34 (m, 2H). 13C NMR (126 MHz, CDCl3) δ 173.8, 172.1, 156.3, 152.5, 51.6, 47.4, 41.1, 33.6, 31.9, 31.8, 29.3, 25.8, 24.6, 24.1 ppm. MS (ESI) m/z calculated [M+H]+: 323.36; found [M-H]+: 321.22. Methyl 6-(5-((6-isocyanohexanamido)methyl)-1H-tetrazol-1-yl)hexanoate (7.3): The product was obtained as a yellow oil (74%, 0.259 g). 1H NMR (500 MHz, CDCl3) δ 7.48 (t, J = 5.7 Hz, 1H), 4.64 (d, J = 5.9 Hz, 2H), 4.40 (t, J = 7.3, 2H), 3.59 (s, 3H), 3.38-3.31 (m, 2H), 2.29-2.19 (m, 4H), 1.89-1.86 (m, 2H), 1.65-1.59 (m, 6H), 1.45-1.38 (m, 2H), 1.35-1.29 (m, 2H). 13C NMR (126 MHz, CDCl3) δ 173.7, 173.5, 155.5, 152.6, 51.6, 47.4, 41.4, 35.5, 33.6, 31.6, 29.3, 28.6, 25.8, 24.4, 24.1 ppm. MS (ESI) m/z calculated [M+H]+: 351.42; found [M-H]+: 349.27.
Methyl 4-(5-(1-(4-isocyanobutanamido)-3-phenylpropyl)-1H-tetrazol-1-yl)butanoate (7.4):
The product was obtained as a yellow oil (56%, 0.222 g). 1H NMR (500 MHz, CDCl3) δ 7.69 (d, J = 8.4 Hz, 1H), 7.24-7.21 (m, 2H), 7.17 (t, J = 7.4 Hz, 1H), 7.08 (d, J = 7.3 Hz, 2H), 5.29-5.25 (m, 1H), 4.47-4.35 (m, 1H), 4.29-4.26 (m, 1H), 3.63 (s, 3H), 3.38 (bs, 2H), 2.77-2.59 (m, 2H), 2.43- 2.38 (m, 1H), 2.38-2.26 (m, 4H), 2.27-2.16 (m, 1H), 2.12-2.05 (m, 2H), 1.98-1.84 (m, 2H). 13C NMR (126 MHz, CDCl3) δ 172.5, 171.6, 162.0, 155.7, 139.8, 128.7, 128.3, 126.5, 51.9, 46.5, 42.0, 41.0, 35.0, 31.9, 31.8, 30.4, 24.6, 24.5 ppm. MS (ESI) m/z calculated [M+H]+: 399.46; found [M-H]+: 397.18.
172
Methyl 6-(5-(1-(6-isocyanohexanamido)-3-phenylpropyl)-1H-tetrazol-1-yl)hexa-noate (7.5):
The product was obtained as a yellow oil (56%, 0.254 g). mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 7.64 (dd, J = 15.7, 8.7 Hz, 1H), 7.27-7.24 (m, 1H), 7.27-7.24-7.20 (m, 1H), 7.19-7.14 (m, 1H), 7.08 (d, J = 7.4, 2H), 5.29-5.25 (m, 1H), 4.33-4.29 (m, 1H), 4.29-4.15 (m, 1H), 3.62 (s, 3H), 3.33-3.30 (m, 1H), 2.75-2.57 (m, 2H), 2.37-3.30 (m, 1H), 2.25 (t, J = 7.4 Hz, 2H), 2.24-2.08 (m, 2H), 1.99 (d, J = 21.1 Hz, 2H), 1.82-1.70 (m, 2H), 1.67-1.53 (m, 4H), 1.43-1.35 (m, 1H), 1.33-1.15 (m, 3H). 13C NMR (126 MHz, CDCl3) δ 174.1, 173.5, 171.0, 156.2, 156.1, 140.4, 140.3, 129.1, 128.8, 128.6, 128.4, 127.3, 126.9, 52.0, 47.7, 42.2, 42.1, 41.8, 41.7, 36.0, 35.6, 34.1, 32.3, 29.8, 29.2, 26.3, 24.9, 24.6, 23.2 ppm. MS (ESI) m/z calculated [M+H]+: 455.27; found [M]+: 454.23.
Methyl 6-(5-(1-(4-isocyanobutanamido)-3-phenylpropyl)-1H-tetrazol-1-yl)hexa-noate (7.6):
The product was obtained as a yellow oil (50%, 0.213 g). 1H NMR (500 MHz, CDCl3) δ 7.73 (d, J = 8.5 Hz, 1H), 7.23-7.21 (m, 2H), 7.26 (t, J = 7.0, 1H), 7.13 (d, J = 7.0, 2H), 5.25-5.21 (m, 1H), 4.29-4.25 (m, 1H), 4.19-4.14 (m, 1H), 3.61 (s, 3H), 3.42 (bs, 2H), 2.69-2.61 (m, 2H), 2.39- 2.37 (m, 1H), 2.36-2.27 (m, 2H), 2.24 (t, J = 7.5 Hz, 2H), 2.18-2.12 (m, 1H), 1.94-1.86 (m, 2H), 1.77-1.70 (m, 2H), 1.59-1.53 (m, 2H), 1.27-1.18 (m, 2H) . 13C NMR (126 MHz, CDCl3) δ 174.0, 172.0, 156.6, 155.8, 140.1, 128.9, 128.6, 126.8, 51.8, 47.5, 42.0, 41.3, 35.4, 33.8, 32.0, 29.6, 26.1, 24.8, 24.4 ppm. MS (ESI) m/z calculated [M+H]+: 427.51; found [M+Na]+: 449.31.
(2S)-methyl 1-(2-((4-(6-isocyanohexanamido) butyl)amino)-2-oxo-1-phenylethyl) pyrrolidine-2-carboxylate (15):
The product was obtained as ayellow oil, 40% yield, 0.182 g; 1H NMR (CDCl3, 500 MHz) δ 8.04 (bs, 1H, NH), 7.25-7.19 (m, 5H), 6.45 (bs, 1H, NH), 4.19 (s, 1H), 3.44 (s, 3H), 3.32 -3.29 (m, 3H), 3.28-3.18 (m, 5H), 3.09-3.05 (q, J = 5 Hz, 1H), 2.12-2.09 (m, 2H), 2.00-1.97 (m, 1H), 1.85-1.77 (m, 3H), 1.61-1.58 (m, 6H), 1.56-1.47 (m, 4H), 1.26 (t, J = 5 Hz, 2H) ppm; 13C NMR (CDCl3, 126 MHz) δ 175.9, 172.8, 172.0, 155.2, 136.6, 128.9, 128.2, 128.2, 73.0, 61.5, 54.2, 51.5, 45.6, 45.6, 41.1 (t, J = 6.3 Hz), 38.7, 38.4, 35.7, 30.4, 28.5, 28.5, 26.9, 26.2, 25.6, 24.4, 23.9, 8.26 ppm. MS (ESI) m/z calculated [M+H]+: 457.27; found [M+H]+: 457.36.
Procedure and analytical data for the saponification reactions:
The isocyanide ester (1.0 mmol) is dissolved in EtOH and potassium hydroxide (1.5 mmol) is added. The reaction is stirred at room temperature. After consumption of the starting material indicated by TLC, the solvent is removed under vacuum and the potassium salt is subjected directly to the next step.
173 Procedure and analytical data for the macrocyclization reactions
Aldehyde (1.0 mmol) and amine (1.0 mmol) were stirred at room temperature for 30 min. Then a solution of α-isocyano-ω-carboxylic acids (1.0 mmol) and ammonium chloride (1.5 mmol) in MeOH (0.01 M, 100 mL) were added into the reaction mixture and stirred further at room temperature for 16 h. The solvent was removed under reduced pressure and the residue was purified using flash chromatography (Pet ether-Ethyl acetate 1:1 in case of compounds 4 and DCM-methanol 9:1 for compounds 9).
3-isopropyl-4-(naphthalen-1-ylmethyl)-1,4-diazacyclohexadecane-2,5-dione (4.1): The product was obtained as a white solid (45%, 0.196 g, mp 109 -111 o C). 1H NMR (500 MHz, CDCl3) δ 7.93-7.89 (m, 2H), 7.78-7.77 (m, 1H), 7.56-7.52 (m, 2H), 7.41-7.40 (m, 1H), 7,26 (bs, 1H), 7.05 (bs, 1H), 5.12 (dd, J = 34.5 Hz, 18.0 Hz, 2H), 4.30 (bs, 1H), 3.42 (bs, 1H), 3.19 (bs, 1H), 2.55 (bs, 1H), 2.31 (bs, 1H), 1.52 -1.46 (m, 5H), 1.38 (bs, 5H), 1.25 (bs, 4H), 1.11-1.08 (m, 2H), 0.95 (d, J = 4.0 Hz, 6 Hz). 13 C NMR (126 MHz, CDCl3) δ 176.6, 170.9, 133.9, 132.2, 130.5, 129.3, 128.1, 126.6, 126.1, 125.3, 123.4, 122.3, 39.5, 33.2, 29.0, 27.6, 27.3, 27.1, 26.6, 26.5, 26.3, 26.1, 25.0, 24.3, 20.2, 20.0 ppm. HRMS (ESI) m/z calculated [M+H]+: 437.31626; found [M+H]+: 437.31597
4-benzyl-3-cyclopropyl-1,4-diazacyclohexadecane-2,5-dione (4.2):
The product was obtained as a clear oil (34%, 0.130 g). 1H NMR (500 MHz, CDCl3) δ 7.35 - 7.32 (m, 2H), 7.27-7.24 (m, 3H), 6.51 (bs, 1H), 4.87 (d, J = 18.0 Hz, 1H) 4.74 (d, J = 18.0 Hz, 1H), 3.99 (d, J = 10.0 Hz, 1H), 3.72-3.45 (m, 2H), 3.03-2.97 (m, 1H), 2.46-2.40 (m, 1H), 2.27-2.21 (m, 1H), 1.80-1.74 (m, 2H), 1.60-1.49 (m, 1H), 1.47-1.43 (m, 2H), 1.35 (bs, 7H), 1.32-1.22 (m, 10H), 0.66-0.61 (m, 1H), 0.32-0.24 (m, 2H), 0.20-0.14 (m, 1H). 13C NMR (126 MHz, CDCl3) δ 175.7, 171.1,138.1, 128.7, 127.3, 126.5, 64.2, 49.5, 39.4, 33.1, 29.2, 27.4, 27.1, 26.5, 26.4, 26.1, 25.6, 25.1, 24.7, 10.3, 5.4, 5.1 ppm. HRMS (ESI) m/z calculated [M+H]+: 385.28495; found [M+H]+: 385.28495.
3-isopropyl-4-(2-(trifluoromethyl)benzyl)-1,4-diazacyclohexadecane-2,5-dione (4.3): The product was obtained as a white solid (38%, 0.172 g, mp 167 -169 o C). 1H NMR (500 MHz, CDCl3) δ 7.66 (d, J = 7.5 Hz, 1H), 7.48 (t, J = 7.5, 1H), 7.37 (t, J = 7.5, 1H), 7,26 - 7.25 (m, 1H), 4,81 (dd, J = 56,8 Hz, 18.0 Hz, 2H), 4,24 (bs, 1H), 3.49 (d, J = 4.0 Hz, 1H), 3.40 - 3.36 (m, 1H), 3.19 (bs, 1H), 2.54 (bs, 1H), 2.26 - 2.17 (m, 2H), 1.64 - 1.50 (m, 4H), 1.47 - 1.41 (m, 5H), 1.34 (bs, 5H), 1.25 - 1.23 (m, 3H), 1.15 - 1.10 (m, 1H), 1.00 - 0.98 (m, 1H), 0.96 (d, J = 6.5 Hz, 3H), 0.92 (d, J = 6.5 Hz, 3H). 13C NMR (126 MHz, CDCl3) δ 176.2, 161.0, 132.1, 127.5, 127.2, 126.5, 39.5, 33.0, 28.9, 27.6, 27.3, 26.9, 26.6, 26.5, 26.3, 26.1, 24.9, 23.9, 20.1 ppm. HRMS (ESI) m/z calculated [M+H]+: 455.28799; found [M+H]+: 455.28750.
174
4-benzyl-3-isopropyl-1,4-diazacyclohexadecane-2,5-dione (4.4):
The product was obtained as a white solid (34%, 0.131 g, mp 112 -114 o C). 1H NMR (500 MHz, CDCl3) δ 7.33-7.30 (m, 2H), 7.28- 7.24 (m, 1H), 7.19 (d, J = 7.5 Hz, 2H), 6.99 (bs, 1H), 4.63 (q, J = 17.0 Hz, 2H), 4.22 (bs, 1H), 3.41 (bs, 1H), 3.15 (bs, 1H), 2.51 (bs, 1H), 2.44-2.29 (m, 2H), 1.64-1.62 (m, 1H), 1.51-1,43 (m, 3H), 1.39-1.22 (m, 12H), 1.17-1.11 (m, 1H), 1.09-1.01 (m, 1H), 0.94 (d, J = 6.5 Hz, 3H), 0.81 (d, J = 6.5 Hz, 3H). 13C NMR (126 MHz, CDCl3) δ 176.1, 171.1, 137.6, 128.7, 127.6, 127.0, 39.4, 33.3, 28.9, 27.4, 27.1, 26.9, 26.5, 26.4, 26.1, 25.9, 25.0, 24.3 20.2, 19.6 ppm. HRMS (ESI) m/z calculated [M+H]+: 387.3006; found [M+H]+: 387.30055. 1-benzyl-2-isopropyl-1,4,9-triazacyclotetradecane-3,10,14-trione (4.5):
The product was obtained as a clear solid (37%, 0.138 g, mp 236 -238 o C). 1H NMR (500 MHz, MeOH-D4) δ 7.36 - 7.31 (m, 1H), 7.28-7.24 (m, 3H), 7.19-7.16 (m, 1H), 5.06 (d, J = 14.0 Hz, 1H), 4.95-4.91 (m, 1H), 4.80 (d, J = 12.5, 1H), 3.88 (d, J = 10.0 Hz, 1H), 3.80-3.77 (m, 1H), 3.73-3.70 (m, 1H), 2.55 - 2.51 (m, 2H), 2.49-2.44 (m, 2H), 2.24-2.16 (m, 3H), 2.15 - 2.05 (m, 2H), 1.67-1.56 (m, 3H), 1.36-1.28 (m, 1H), 0.88 (d, J = 6.5 Hz, 3H), 0.59 (d, J = 6.5 Hz, 3H). 13C NMR (126 MHz, MeOH-D4) δ 175.8, 175.5, 172.6, 141.1, 129.4, 129.3, 129.3, 129.1, 129.0, 129.0, 127.8, 68.8, 68.8, 40.2, 40.2, 40.1, 39.3, 39.2, 35.2, 31.8, 31.7, 29.7, 29.7, 28.8, 28.5, 28.3, 21.3, 20.8, 20.6, 20. 6, 20.1, 19.9 ppm. HRMS (ESI) m/z calculated [M+H]+: 374.24382; found [M+H]+: 374.24349.
8-benzyl-9-isopropyl-1,3,8,11-tetraazacyclohexadecane-2,7,10-trione (4.6):
The product was obtained as a clear oil (36%, 0.144 g). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 7.34-7.29 (m, 2H), 7.26-7.21 (m, 3H), 7.17-7.12 (m, 3H), 6.92 (bs, 1H), 5.64 (bs, 1H), 5.56 (bs, 1H), 4.76 (d, J = 17.5 Hz, 2H), 4.57 (d, J = 17.0 Hz, 1H), 4.31 (bs, 1H), 3.41-3.36 (m, 2H), 3.23-3.19 (m, 1H), 3.12-3.09 (m, 2H), 3.03-2.99 (m, 1H), 2.50-2.40 (m, 4H), 2.04 (bs, 1H), 1.99-1.93 (m, 1H), 1.70-1.68 (m, 3H), 1.63-1.40 (m, 6H), 1.29-1.26 (m, 1H), 0.96-0.93 (m, 4H), 0.84 (d, J = 6.5 Hz, 3H), 0.75 (d, J = 6.5 Hz, 1H). 13C NMR (126 MHz, CDCl3) δ 176.5, 175.3, 174.6, 170.0, 169.9, 160.5, 159.7, 139.3, 136.8, 129.1, 128.2, 128.1, 127.7, 126.7, 126.4, 67.1, 50.1, 46.6, 40.8, 39.6, 39.4, 39.4, 38.4, 37.8, 31.5, 30.7, 30.6, 28.5, 27.2, 27.2, 26.7, 25.9, 24.0, 22. 8, 22.5, 21.4, 21.3, 21.2, 20.0, 19.9, 19.4, 19.2 ppm. HRMS (ESI) m/z calculated [M+H]+: 403.27037; found [M+H]+: 403.27002. 4-benzyl-3-isopropyl-1,4-diazacyclopentadecane-2,5-dione (4.7):
The product was obtained as a yellow solid (27%, 0.100 g, mp 233 -235 o
C). 1H NMR (500 MHz, CDCl3) δ 7.37-7.30 (m, 2H), 7,29-7.28 (m, 1H), 7,25-7.22 (m, 2H), 4.62 (t, J = 17.5 Hz, 2H), 3.48-3.07 (m, 2H), 2.53 (bs, 1H), 2.39 (t, J = 6.0 Hz, 2H), 1.77 (bs, 1H), 1.51-1.43 (m, 2H), 1.40-1.27 (m, 8H), 1.25-1.19 (m, 3H), 1.10 - 1.04 (m, 3H), 0.93
175 (d, J = 6.5 Hz, 3H), 0.79 (d, J = 6.5 Hz, 3H). 13C NMR (126 MHz, CDCl3) δ 176.1, 171.1, 128.8, 127.7, 127.3, 39.0, 33.2, 29.0, 28.3, 27.1, 27.1, 26.9, 26.6, 26.4, 26.2, 23.1, 20.2, 19.9 ppm. HRMS (ESI) m/z calculated [M+H]+: 373.28495; found [M+H]+: 373.28479. 4-benzyl-3-isopropyl-1,4-diazacyclotridecane-2,5-dione (4.8):
The product was obtained as a clear oil (23%, 0.079 g). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 7.41-7.31 (m, 4H), 7.30-7.28 (m, 2H), 7.26-7.25 (m, 1H), 6.23 (d, J = 7.0, 1H), 4.88 (d, J = 18.0 Hz, 1H), 4.80 (d, J = 11.0 Hz, 1H), 4.67 (d, J = 18.0 Hz, 1H), 3.86-3.80 (m, 1H), 3.05-2.98 (m, 1H), 2.77-2.68 (m, 2H), 2.62-2.56 (m, 1H), 2.37-2.33 (m, 1H), 2.28-2.23 (m, 1H), 2.12-2.04 (m, 1H), 1.86-1.81 (m, 1H), 1.56-1.51 (m, 3H), 1.48-1.45 (m, 3H), 1.42-1.37 (m, 3H), 1.33-1.26 (m, 6H), 1.24-1.21 (m, 1H), 0.90 (d, J = 6.5 Hz, 3H), 0.83 (d, J = 6 Hz, 1H), 0.64 (d, J = 6.5 Hz, 3H), 0.60 (d, J = 5.5 Hz, 1H). 13C NMR (126 MHz, CDCl3) δ 177.4, 176.3, 171.7, 170.4, 138.2, 136.1, 129.6, 128.9, 128.7, 128.4, 127.3, 126.9, 64.2, 55.9, 47.8, 39.4, 39.0, 34.3, 33.9, 28.2, 27.0, 26.9, 26.3, 26.1, 25.4, 25.3, 25.0, 24.9, 24.8, 24.7, 23.9, 23.1, 20.3, 20.2, 20.0 ppm. HRMS (ESI) m/z calculated [M+H]+: 345.25365; found [M+H]+: 345.25331. 4-benzyl-3-isopropyl-1,4-diazacyclododecane-2,5-dione (4.9):
The product was obtained as a clear oil (29%, 0.095 g). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 7.43 (t, J = 7.5 Hz, 1H), 7.39-7.37 (m, 1H), 7.35-7.30 (m, 3H), 7.27-7.24 (m, 2H), 6.27 (d, J = 7.5 Hz, 1H), 4.84 (d, J = 11.5 Hz, 1H), 4.79 (d, J = 18.5, 1H), 4.64 (d, J = 18 Hz, 1H), 3.76-3.68 (m, 1H), 3.39-3.35 (m, 1H), 3.02-2.97 (m, 1H), 2,81-2.75 (m, 2H), 2.55-2.39 (m, 1H), 2.46-2.40 (m, 1H), 2.37-2.27 (m, 1H), 2.24-2.18 (m, 1H), 2.17-2.10 (m, 1H), 2.04-1.96 (m, 1H), 1.67-1.61 (m, 2H), 1.58-1.49 (m, 4H), 1.48-1.40 (m, 2H), 1.38-1.30 (m, 3H), 1.29-1.22 (m, 3H), 1.20-1.13 (m, 2H), 1.00 - 0.94 (m, 2H), 0.93 (d, J = 6.0 Hz, 3H), 0.81 (d, J = 5.5 Hz, 1H), 0.65 (d, J = 6.5 Hz, 3H), 0.53 (d, J = 6 Hz, 1H). 13C NMR (126 MHz, CDCl3) δ 178.2, 176.4, 172.0, 170.5, 138.0, 136.0, 129.7, 129.6, 128.9, 128.8, 128.8, 128.8, 128.7, 128.7, 128.4, 127.3, 126.6, 126.6, 68.4, 64.5, 55.5, 48.0, 39.3, 39.0, 38.5, 35.0, 34.0, 33.8, 30.9, 30.0, 29.2, 29.0, 28.6, 28.5, 28.0, 27.7, 26.8, 26.5, 26.4, 26.2, 25.9, 25.8, 25.1, 25.1, 24.9, 24.7, 24.3, 24.2, 24.1, 23.7, 23.5, 20.3, 20.2, 20.1, 19.9 ppm. HRMS (ESI) m/z calculated [M+H]+: 331.23800; found [M+H]+: 331.23768. 4-benzyl-3-(tert-butyl)-1,4-diazacyclohexadecane-2,5-dione (4.10):
The product was obtained as a clear oil (26%, 0.104 g). 1H NMR (500 MHz, CDCl3) δ 7.33 (t, J = 7.5 Hz, 2H), 7.25-7.20 (m, 3H), 5.07 (bs, 1H), 4.81 (d, J = 18.0 Hz, 1H), 3.72-3.45 (m, 2H), 2.42-2.37 (m, 1H), 1.75 (bs, 1H), 1.60-1.54 (m, 1H), 1.44-1.09 (m, 18H), 1.07 (s, 9H). 13C NMR (126 MHz, CDCl3) δ 177.2, 170.4, 128.6, 127.0, 126.3, 39.0, 33.3, 28.8, 28.2, 27.9, 27.8, 27.8, 27.7, 27.2, 27.1, 26.9, 26.8, 26.4, 26.2, 25.4, 25.0 ppm. HRMS (ESI) m/z calculated [M+H]+: 401.31626; found [M+H]+: 401.31554.
176
3-cyclopropyl-4-(2-(trifluoromethyl)benzyl)-1,4-diazacyclohexadecane-2,5-dione (4.11):
The product was obtained as a clear oil (25%, 0.113 g). 1H NMR (500 MHz, CDCl3) δ 7.67 (d, J = 7.5 Hz, 1H), 7.59-7.53 (m, 2H), 7.38 (t, J = 7.5, 1H), 6.43 (bs, 1H), 5.01 (dd, J = 51.8 Hz, 18.5 Hz, 2H), 3.97 (d, J = 10.5 Hz, 1H), 3.67-3.59 (m, 1H), 3.04-2.99 (m, 1H), 2.31-2.26 (m, 1H), 2.20-2.14 (m, 1H), 1.80-1.72 (m, 1H), 1.57-1.53 (m, 1H), 1.49-1.38 (m, 9H), 1.30-1.21 (m, 10H), 0.69-0.64 (m, 1H), 0.34-0.31 (m, 2H), 0.28-0.24 (m, 1H). 13C NMR (126 MHz, CDCl3) δ 175.8, 170.8, 136.7, 132.1, 127.7, 127.4, 126.3, 126.3, 125.6, 123.4, 64.4, 46.0, 39.4, 32.9, 29.3, 27.6, 26.9, 26.5, 26.5, 26.1, 25.6, 25.0, 24.4, 10.0, 5.4, 5.2 ppm. HRMS (ESI) m/z calculated [M+H]+: 453.27234; found [M+H]+: 453.27178.
3-(tert-butyl)-4-(pyridin-3-ylmethyl)-1,4-diazacyclohexadecane-2,5-dione (4.12): The product was obtained as a white solid (28%, 0.112 g, mp 145 -147 oC). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 8.54-8.52 (m, 2H), 7.54 (d, J = 8.0 Hz, 1H), 7.29-7.27 (m, 1H), 6.03 (bs, 1H), 5.11 (bs, 1H), 4.90 (d, J = 17.5 Hz, 1H), 3.73 (bs, 1H), 3.06-2.71 (m, 1H), 2.34-2.24 (m, 1H), 2.17 (bs, 1H), 1.92 (bs, 1H), 1.71 (bs, 1H), 1.58 (bs, 1H), 1.43-1.29 (m, 9H), 1.25-1,19 (m, 5H), 1.14 (s, 2H), 1.07 (s, 9H). 13C NMR (126 MHz, CDCl3) δ 176.9, 170.4, 149.7, 148.7, 148.4, 148.0, 135.7, 134.3, 123.6, 123.1, 68.7, 39.2, 38.9, 34.1, 33.4, 28.9, 28.2, 28.1, 28.0, 27.3, 27.3, 27.1, 26.7, 26.4, 26.3, 26.0, 25.8, 25.6, 25.2, 24.5 ppm. HRMS (ESI) m/z calculated [M+H]+: 402.31150; found [M+H]+: 402.31090.
3-cyclopropyl-4-(pyridin-3-ylmethyl)-1,4-diazacyclohexadecane-2,5-dione (4.13): The product was obtained as a clear oil (28%, 0.107 g). 1H NMR (500 MHz, CDCl3) δ 8.56 (bs, 2H), 7.66 (d, J = 8.0 Hz, 1H), 7.33-7.30 (m, 1H), 6.48 (bs, 1H), 4.88 (dd, J = 77.5 Hz, 18.0 Hz, 2H), 4.01 (d, J = 10.0 Hz, 1H), 3.75-3.59 (m, 2H), 3.00-2.96 (m, 1H), 2.43-2.37 (m, 1H), 2.27-2.22 (m, 1H), 1.81-1.76 (m, 1H), 1.54-1.49 (m, 1H), 1.45-1.41 (m, 2H), 1.34-1.23 (m, 18H) 0.69-0.63 (m, 1H), 0.36-0.25 (m, 2H), 0.22-0.17 (m, 1H). 13C NMR (126 MHz, CDCl3) δ 175.5, 170.9, 148.6, 148.0, 134.5, 123.8, 63.9, 47.1, 39.4, 33.1, 29.9, 29.2, 27.5, 27.0, 26.5, 26.4, 26.1, 25.5, 25.1, 24.6, 10.5, 5.6, 5.1 ppm. HRMS (ESI) m/z calculated [M+H]+: 386.28020; found [M+H] +: 386.28027. 3-isopropyl-4-(pyridin-3-ylmethyl)-1,4-diazacyclohexadecane-2,5-dione (4.14): The product was obtained as a white solid (20%, 0.077 g, mp 138 -140 oC). 1H NMR (500 MHz, CDCl3) δ 8.53 (d, J = 4.5 Hz, 1H), 8.49 (bs, 1H), 7.54 (d, J = 8.0 Hz, 1H), 7.26-7.24 (m, 1H), 6.78 (bs, 1H), 4.67 (dd, J = 33.0 Hz, 17.5 Hz, 2H), 4.33 (bs, 1H), 3.48 (bs, 1H), 3.10 (bs, 1H), 2.46 (bs, 1H), 2.37-2.31 (m, 2H), 1.83 (bs, 1H), 1.72-1.64 (m, 2H), 1.43-1.36 (m, 6H), 1.32-1.26 (m, 5H), 1.23-1.16 (m, 3H), 1.15-1.05 (m, 1H), 0.99-0.96 (m, 1H), 0.95 (d, J = 6.5 Hz, 3H), 0.82 (d, J = 7.0 Hz, 3H). 13C NMR (126 MHz, CDCl3) δ 175.8, 170.9, 149.1, 148.8, 134.9, 123.6, 39.4, 33.3, 28.9, 28.1, 27.5, 27.1, 26.9, 26.5, 26.1, 25.9, 25.0, 24.3, 20.1, 19.5 ppm. HRMS (ESI) m/z calculated [M+H]+: 388.29585; found [M+H]+: 388.29561.
177 9-benzyl-10-isobutyl-6,7,9,10,12,13,14,15,17,18-decahydrotetrazolo[1,5-a][1,4,9,12] tetraazacyclohexadecine-8,11,16(5H)-trione (9.1):
The product was obtained as a white solid (30%, 0.136 g, mp 215-217 oC). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 8.03 (t, J = 4.0 Hz, 1H), 7.89 (t, J = 5.5 Hz, 1H), 7.28 (d, J = 7.5 Hz, 1H), 7.23 (d, J = 7.5 Hz, 2H), 7.19 (d, J = 7.5 Hz, 1H), 7.01 (d, J = 7.5 Hz, 2H), 5.33 (dd, J = 8.0, 6.0 Hz, 1H), 5.02-4.93 (m, 1H), 4.81 (dd, J = 15.5, 5.5 Hz, 1H), 4.49 (d, J = 17.5 Hz, 1H), 4.32 (d, J = 5.5 Hz, 1H), 4.28-2.23 (m, 3H), 3.18-3.16 (m, 2H), 3.06-2.96 (m, 1H), 2.53-2.40 (m, 4H), 2.39-2.24 (m, 4H), 1.87-1.64 (m, 4H), 1.56-1.53 (m, 2H), 1.43-1.29 (m, 2H), 0.91 (d, J = 6.5 Hz, 3H), 0.84 (d, J = 6.5 Hz, 1H), 0.79 (d, J = 6.5 Hz, 3H), 0.57 (d, J = 6.0 Hz, 1H). 13C NMR (126 MHz, CDCl3) δ 175.7, 175.4, 173.8, 172.9, 170.7, 169.7, 153.6, 153.2, 153.2, 138.8, 137.3, 128.9, 128.4, 128.3, 127.5, 127.1, 126.1, 59.6, 56.0, 48.7, 47.2, 46.8, 41.3, 40.9, 37.9, 37.1, 34.7, 32.5, 32.3, 28.7, 28.3, 25.2, 24.6, 23.6, 23.3, 23.1, 22.9, 22.8, 22.5 ppm. HRMS (ESI) m/z calculated [M+H]+: 456.27176; found [M]+: 455.27144. 11-(4-Chlorophenethyl)-12-isopropyl-6,7,8,9,11,12,14,15,16,17,19,20-dodecahydro- tetrazolo[1,5-a][1,4,9,12] tetraazacyclooctadecine-10,13,18(5H)-trione (9.2):
The product was obtained as a white solid (27%, 0.139 g, mp 103-105 oC). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 7.49 (t, J = 5.2 Hz, 1H), 7.21 (d, J = 8.0, 2H), 7.16 (s, 1H), 7.03 (d, J = 8.0 Hz, 2H), 4.91 (dd, J = 7.0 Hz, 1H), 4.58 (dd, J = 5.0 Hz, 1H), 4.39- 4.30 (m, 1H), 4.27-4.18 (m, 1H), 3.46-3.33 (m, 2H), 3.34-3.13 (m, 2H), 2.91-2.77 (m, 1H), 2.77-2.61 (m, 1H), 2.53-2.45 (m, 2H), 2.41-2.25 (m, 2H), 2.21 (t, J = 8.0 Hz, 2H), 2.11- 1.97 (m, 1H), 1.98-1.69 (m, 4H), 1.61-1.57 (m, 1H), 1.49-1.47 (m, 1H), 1.10-0.95 (m, 1H), 0.93 (t, J = 7.0 Hz, 3H), 0.79 (dd, J = 7.0 Hz, 3H) ppm. 13C NMR (126 MHz, CDCl3) δ 175.1, 173.9, 172.7, 172.5, 171.0, 169.0, 152.8, 152.4, 138.2, 136.6, 132.4, 131.7, 130.4, 130.1, 128.7, 128.3, 66.4, 47.4, 47.2, 44.8, 40.7, 37.8, 34.8, 34.7, 33.4, 32.9, 32.7, 32.4, 32.1, 31.1, 29.3, 28.4, 27.3, 26.4, 25.4, 25.0, 24.6, 23.9, 23.1, 22.8, 19.9, 19.8, 19.1, 18.6 ppm. HRMS (ESI) m/z calculated [M+H]+: 518.26409; found [M+H]+: 518.26405. 9'-(4-Methoxybenzyl)-6',7',12',13',14',15',17',18'-octahydro-5'H-spiro[cyclo hexane-1,10'-tetrazolo[1,5-a][1,4,9,12] tetraazacyclohexadecine]-8',11',16'(9'H)-trione (9.3):
The product was obtained as a white solid (25%, 0.124 g, mp 220-222 o C). 1H NMR (500 MHz, DMSO) δ 8.42 (t, J = 6.0 Hz, 1H), 7.26 (d, J = 8.5 Hz, 2H), 7.24 (bs, 1H), 6.95 (d, J = 8.5 Hz, 2H), 4.70 (d, J = 6.0 Hz, 2H), 4.66 (s, 2H), 4.32 (t, J = 8.0 Hz, 2H), 3.75 (s, 3H), 3.72 (s, 1H), 3.08 (bs, 2H), 2.53 (s, 1H), 2.28- 2.22 (m, 4H), 1.94-1.91 (m, 2H), 1.69-1.54 (m, 5H), 1.44-1.31 (m, 5H). 13C NMR (126 MHz, DMSO) δ 173.8, 173.5, 173.1, 158.6, 153.1, 131.0, 128.1, 114.4, 65.6, 55.6, 55.4, 47.2, 47.1, 37.9, 33.0, 32.5, 32.4, 30.9, 25.6, 25.4, 24.9, 22.7 ppm. HRMS (ESI) m/z calculated [M+H]+: 498.28233; found [M+H]+: 498.28202.
178
11-(4-Chlorobenzyl)-12-isopropyl-6,7,8,9,11,12,14,15,16,17,19,20 -dodecahydro tetrazolo[1,5-a][1,4,9,12]tetraazacyclooctadecine-10,13,18(5H)-trione (9.4):
The product was obtained as a white solid (34%, 0.171 g, mp 149-151 oC). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 8.40 (t, J = 6.0 Hz, 1H), 8.25 (bs, 1H), 7.74 (t, J = 6.0 Hz, 1H), 7.38 (bs, 1H), 7.21 (d, J = 8.5 Hz, 1H), 7.08 (s, 2H), 7.03 (d, J = 8.5 Hz, 1H), 4.88 (dd, J = 6.5, 6.0 Hz, 1H), 4.79 (d, J = 15.0 Hz, 1H), 4.64 (dd, J = 6.0, 5.5 Hz, 1H), 4.60- 4.51 (m, 1H), 4.48 (m, 1H), 4.42-4.33 (m, 1H), 4.24 (t, J = 6.7 Hz, 1H), 4.18 (d, J = 15.0 Hz, 1H), 3.18-3.02 (m, 1H), 2.74 (m, 1H), 2.46-2.32 (m, 2H), 2.27 (m, 2H), 2.16-1.95 (m, 1H), 1.80 (m, 2H), 1.71-1.59 (m, 2H), 1.58-1.46 (m, 1H), 1.39 (m, 1H), 1.09 (m, 1H), 0.90 (dd, J = 6.5 Hz, 3H), 0.76 (dd, J = 6.5 Hz, 3H) . 13C NMR (126 MHz, CDCl3) δ 175.2, 174.9, 173.2, 173.1, 170.4, 168.4, 152.8, 152.7, 137.4, 135.8, 133.2, 132.1, 129.5, 128.8, 128.1, 127.9, 66.3, 47.2, 47.2, 45.1, 40.8, 38.5, 34.8, 33.5, 32.9, 32.8, 32.6, 31.7, 29.0, 28.6, 27.3, 26.9, 25.2, 25.1, 24.3, 23.8, 23.3, 22.3, 20.3, 19.9, 19.4, 18.6 ppm. HRMS (ESI) m/z calculated [M+H]+: 504.24844; found [M+H]+: 504.24842.
11-Benzyl-12-isobutyl-6,7,8,9,11,12,14,15,16,17,18,19,21,22-tetradecahydrotetrazolo [1,5-a][1,4,11,14]tetraazacycloicosine-10,13,20(5H)-trione (9.5):
The product was obtained as a white solid (36%, 0.184 g, mp 136-138 oC). 1H NMR (500 MHz, CDCl3) δ 7.29 (t, J = 7.5 Hz, 3H), 7.21 (t, J = 7.5 Hz, 1H), 7.11 (d, J = 7.5 Hz, 2H), 6.77 (t, J = 5.3 Hz, 1H), 4.95 (t, J = 7.3 Hz, 1H), 4.75 (dd, J = 15.5, 6.0 Hz, 1H), 4.69 (dd, J = 16.0, 6.0 Hz, 1H), 4.57 (d, J = 5.0 Hz, 2H), 4.30 (t, J = 7.3 Hz, 2H), 3.49-3.37 (m, 2H), 2.99-2.93 (m, 1H), 2.37-2.32 (m, 1H), 2.29 (t, J = 6.8 Hz, 2H), 2.23-2.18 (m, 1H), 1.87-1. 81 (m, 2H), 1.79-1.76 (m, 1H), 1.67-1.57 (m, 4H), 1.56-1.51 (m, 1H), 1.49-1.42 (m, 4H), 1.39-1.28 (m, 4H), 1.27-1.20 (m, 2H), 0.80 (d, J = 6.5 Hz, 3H), 0.77 (d, J = 6.6 Hz, 3H). 13C NMR (126 MHz, CDCl3) δ 175.6, 173.8, 171.4, 153.0, 138.2, 129.2, 127.7, 126.4, 77.8, 77.6, 77.3, 56.8, 48.9, 47.5, 39.0, 37.5, 35.7, 33.7, 32.1, 29.5, 29.1, 26.6, 25.8, 25.6, 24.7, 24.5, 23.3, 22.9, 22.8 ppm. HRMS (ESI) m/z calculated [M+H]+: 512.33436; found [M+H]+: 512.33394. 9-(4-Methoxybenzyl)-18-phenethyl-6,7,9,10,12,13,14,15,17,18-decahydrotetrazolo [1,5-a][1,4,9,-12]tetraazacyclohexadecine-8,11,16(5H)-trione (9.6):
The product was obtained as a white solid (30%, 0.159 g, mp 250-252 o
C). A mixture of rotamers is observed; 1H NMR (500 MHz, DMSO) δ 8.63 (d, J = 8.5 Hz, 1H), 8.08 (t, J = 5.5 Hz, 1H), 7.29 (t, J = 7.8 Hz, 2H), 7.18 (dd, J = 14.0, 7.5 Hz, 5H), 7.10 (d, J = 8.5 Hz, 1H), 6.89 (d, J = 8.5 Hz, 1H), 6.87 (d, J = 8.5 Hz, 1H), 5.26-5.21 (m, 1H), 4.45 (s, 2H), 4.38-4.21 (m, 2H), 3.73 (d, J = 6.5 Hz, 3H), 3.18-3.09 (m, 2H), 3.00 (m, 1H), 2.70-2.62 (m, 1H), 2.59-2.53 (m, 2H), 2.38-2.31 (m, 2H), 2.25-2.13 (m, 6H), 2.07 (bs, 1H), 1.88 (bs, 1H), 1.63 (bs, 1H), 1.53 (bs, 1H). 13C NMR (126 MHz, DMSO) δ 174.2, 172.9, 172.8, 172.1, 168.5, 159.0, 158.9, 156.0, 141.4, 141.2, 129.9, 129.8, 129.1, 128.8, 128.7, 126.4, 114.5, 114.3, 55.5, 51.6, 49.4, 46.6, 43.8, 42.7, 38.9, 34.7, 31.8, 29.3, 25.4, 23.9
179 ppm. HRMS (ESI) m/z calculated [M+H]+: 534.28233; found [M+H]+: 534.28231. 11-Benzyl-12-isopropyl-6,7,8,9,11,12,14,15,16,17,18,19,21,22-tetradecahydrotetrazolo [1,5-a][1,4,-11,14]tetraazacycloicosine-10,13,20(5H)-trione (9.7):
The product was obtained as a white solid (34%, 0.169 g, mp 177-179 o C). 1H NMR (500 MHz, CDCl3) δ 7.27 (t, J = 7.5 Hz, 2H), 7.20 (d, J = 7.5 Hz, 1H), 7.10 (d, J = 8.0 Hz, 2H), 4.79 (dd, J = 15.5, 6.0 Hz, 1H), 4.70 (dd, J = 12.5, 6.5 Hz, 1H), 4.62 (dd, J = 16.0, 5.5 Hz, 1H), 4.50 (d, J = 17.5 Hz, 1H), 4.44-4.31 (m, 1H), 4.29 (t, J = 7.3 Hz, 2H), 3.35-3.33 (m, 1H), 3.17-3.01 (m, 1H), 2.41-2.39 (m, 1H), 2.28-2.23 (m, 4H), 1.92 (bs, 1H), 1.79-1.74 (m, 2H), 1.66-1.62 (m, 4H), 1.55-1.26 (m, 6H), 1.18-1.14 (m, 2H), 0.90 (d, J = 6.5 Hz, 3H), 0.77 (d, J = 6.5 Hz, 3H). 13C NMR (126 MHz, CDCl3) δ 175.7, 173.9, 170.8, 152.9, 138.0, 129.1, 127.8, 126.8, 67.6, 47.4, 39.0, 35.5, 33.5, 32.2, 29.4, 28.8, 27.5, 26.7, 25.7, 24.7, 24.2, 20.2, 19.5 ppm. HRMS (ESI) m/z calculated [M+H]+: 498.31871; found [M+H]+ : 498.31877. 1-Benzyl-9'-(4-chlorobenzyl)-6',7',12',13',14',15',17',18'-octahydro-5'H-spiro-
[piperidine-4,10'-tetrazolo[1,5-a][1,4,9,12]tetraazacyclohexadecine]-8',11',16'(9'H)-trione (9.8):
The product was obtained as a white crystalline solid (19%, 0.112 g, mp 163-165 oC). 1H NMR (500 MHz, CDCl3) δ 7.60 (t, J = 5.7 Hz, 1H), 7.40 (d, J = 8.5 Hz, 2H), 7.36 (d, J = 8.5 Hz, 2H), 7.26 (d, J = 7.0 Hz, 2H), 7.23-7.19 (m, 3H), 6.22 (bs, 1H), 4.84 (d, J = 6.0 Hz, 2H), 4.64 (s, 2H), 4.29 (t, J = 8.3 Hz, 2H), 3.52-3.41 (m, 2H), 3.42-3.30 (m, 2H), 2.78-2.65 (m, 2H), 2.45-2.37 (m, 4H), 2.30 (d, J = 12.5 Hz, 4H), 2.13 (m, 2H), 1.97-1.85 (m, 4H) ppm.13C NMR (126 MHz, CDCl3) δ 173.8, 173.5, 173.5, 151.7, 136.07, 133.5, 129.3, 129.1, 128.4, 127.2, 62.7, 49.9, 47.2, 46.29, 38.6, 33.3, 32.2, 30.4, 25.6, 24.8 ppm. HRMS (ESI) m/z calculated [M+H]+: 593.27499; found [M+H]+: 593.27484.
9-(4-Chlorobenzyl)-10-(2-(methylthio)ethyl)-6,7,9,10,12,13,14,15,17,18-decahydro tetrazolo[1,5-a][1,4,9,12] tetraazacyclohexadecine-8,11,16(5H)-trione (9.9):
The product was obtained as a white solid (21%, 0.106 g, mp 198-199 oC). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 8.80 (t, J = 5.3, 1H), 8.75 (bs, 1H), 8.51 (t, J = 5.5, 1H), 8.20 (t, J = 3.7, 1H), 7.30 (d, J = 9.0, 2H), 7.24 (d, J = 3.0, 2H), 7.22 (d, J = 3.5, 2H), 6.97 (d, J = 8.5, 2H), 5.45 (t, J = 7.3, 1H), 5.13 - 5.02 (m, 2H), 4.87 (dd, J = 15.0, 5.5, 1H), 4.75 (dd, J = 15.0, 6.0, 2H), 4.57 (t, J = 6.7, 1H), 4.50 (d, J = 17.5, 1H), 4.39-4.28 (m, 5H), 4.22 (d, J = 15.0, 1H), 3.19-3.12 (m, 2H), 3.04-3.03 (m, 2H), 2.74-2.70 (m, 2H), 2.62-2.49 (m, 6H), 2.46-2.36 (m, 6H), 2.36-2.26 (m, 4H), 2.06 (s, 3H), 2.00 (s, 3H), 1.84-1.67 (m, 4H), 1.65-1.55 (m, 2H) . 13C NMR (126 MHz, CDCl3) δ 175.8, 175.5, 173.5, 173.4, 169.8, 169.2, 153.6, 153.4, 137.3, 135.6, 133.5, 133.2, 130.2, 129.2, 128.6, 127.8, 59.2, 56.5, 53.7, 48.3, 47.3, 46.8, 41.4, 40.9, 34.8, 34.8,
180
32.5, 32.3, 31.4, 30.7, 28.7, 28.5, 28.3, 28.2, 23.6, 23.1, 23.0, 22.4, 15.6, 15.4 ppm. HRMS (ESI) m/z calculated [M+H]+: 508.18921; found [M+H]+: 508.18929.
9-(4-Fluorobenzyl)-10-isobutyl-6,7,9,10,12,13,14,15,17,18-decahydrotetrazolo[1,5-a][1,4,9,12]tetraazacyclohexadecine-8,11,16(5H)-trione (9.10):
The product was obtained as a white crystal (20%, 0.095 g, mp 223-224 oC); mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 8.07 (t, J = 5.7 Hz, 1H), 8.02 (t, J = 3.7 Hz, 1H), 7.30-7.25 (m, 1H), 6.96- 6.92 (m, 2H), 6.92-6.87 (m, 3H), 5.35 (dd, J = 8.5, 6.5 Hz, 1H), 5.10-4.98 (m, 1H), 4.84 (dd, J = 15.5, 6.0 Hz, 1H), 4.80-4.65 (m, 1H), 4.43 (d, J = 17.5 Hz, 1H), 4.31 (d, J = 5.5 Hz, 1H), 4.30-4.22 (m, 3H), 3.22-3.07 (m, 2H), 3.04-2.95 (m, 1H), 2.78-2.69 (m, 1H), 2.58-2.40 (m, 4H), 2.39-2.21 (m, 4H), 2.14-2.12 (d, J = 6.5 Hz, 2H), 1.93-1.91 (m, 1H), 1.87-1.73 (m, 2H), 1.74-1.62 (m, 1H), 1.58-1.49 (m, 2H), 1.37-1.30 (m, 2H), 0.91 (d, J = 6.5 Hz, 3H), 0.85 (d, J = 6.0 Hz, 1H), 0.81 (d, J = 6.5 Hz, 3H), 0.61 (d, J = 6.0 Hz, 1H). 13C NMR (126 MHz, CDCl3) δ 175.8, 175.4, 173.6, 172.9, 170.5, 169.7, 163.0, 161.1, 153.6, 153.3, 134.8, 133.1, 133.0, 130.3, 130.2, 128.9, 128.8, 127.9, 127.8, 115.9, 115.7, 115.2, 115.1, 59.6, 55.8, 47.9, 47.3, 46.8, 45.8, 41.4, 41.0, 38.0, 37.3, 34.9, 34.8, 32.4, 32.3, 28.7, 28.3, 25.3, 24.7, 23.6, 23.2, 23.0, 23.00, 22.9, 22.6, 22.4 ppm. HRMS (ESI) m/z calculated [M+H]+: 474.26234; found [M+H]+: 474.26194.
9-Benzyl-10-isopropyl-6,7,9,10,12,13,14,15,17,18-decahydro tetrazolo[1,5-a][1,4,-9,12]tetraazacyclohexadecine-8,11,16(5H)-trione (9.11):
The product was obtained as a white solid (20%, 0.088 g, mp 220-222 o
C); mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 7.94 (bs, 1H), 7.81 (t, J = 3.5 Hz, 1H), 7.22 (d, J = 7.5 Hz, 1H), 7.14 (t, J = 7.5 Hz, 1H), 7.06- 7.03 (m, 2H), 6.76 (d, J = 6.5 Hz, 1H), 5.10 (dd, J = 16.0, 7.5 Hz, 1H), 4.85 (d, J = 10.5 Hz, 1H), 4.71-4.68 (m, 1H), 4.54 (d, J = 17.5 Hz, 1H), 4.39 (d, J = 17.0 Hz, 1H), 4.24 (dd, J = 15.5, 3.7 Hz, 1H), 4.16-4.11 (m, 1H), 3.17-3.07 (m, 1H), 2.93-2.82 (m, 1H), 2.67-2.54 (m, 1H), 2.60-2.55 (m, 1H), 2.46-2.33 (m, 2H), 2.31-2.22 (m, 2H), 2.19-2.14 (m, 1H), 1.94-1.82 (m, 1H), 1.70-1.57 (m, 1H), 0.93 (dd, J = 8.8, 3.1 Hz, 3H), 0.78 (dd, J = 14.5, 6.5 Hz, 3H) ppm. 13C NMR (126 MHz, CDCl3) δ 13C NMR (126 MHz, CDCl3) δ 175.8, 174.6, 173.1, 172.9, 169.6, 168.5, 153.3, 152.7, 138.6, 137.2, 128.6, 128.5, 128.0, 127.2, 126.8, 125.7, 66.6, 62.9, 47.7, 47.2, 46.4, 46.0, 40.8, 40.7, 34.7, 34.3, 32.8, 31.9, 29.0, 28.5, 27.1, 26.8, 24.6, 23.3, 22.2, 22.2, 2 0.8, 20.1, 18.8, 18.8 ppm. HRMS (ESI) m/z calculated [M+H]+: 442.25611; found [M+H]+: 442.25562.
9,10-Dibenzyl-6,7,9,10,12,13,14,15,17,18-decahydrotetrazolo[1,5-a][1,4,9,12]tetraaza cyclohexadecine-8,11,16(5H)-trione (9.12):
The product was obtained as a white solid (17%, 0.083 g, mp 125-127 oC); mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 8.26 (bs, 1H), 7.82 (t, J = 5.3 Hz, 1H), 7.50 (bs, 1H), 7.37 (d, J = 7.5 Hz, 1H), 7.22 (d, J = 7.0 Hz, 3H), 7.19-7.17 (m, 6H), 7.15 (d, J = 7.0 Hz, 2H), 6.95 (d, J = 7.0 Hz, 3H), 5.23 (t, J = 6.8, 1H), 4.85 (dd, J = 15.0, 6.0 Hz, 2H), 4.79 (dd, J = 14.0, 7.5 Hz, 1H), 4.55
181 (dd, J = 15.0, 5.0, 1H), 4.48 (d, J = 17.5, 2H), 4.40 (dd, J = 15.0, 5.0, 1H), 4.34 (dd, J = 10.0, 4.0 Hz, 1H), 4.31-4.23 (m, 1H), 4.15 (d, J = 17.5, 2H), 3.33-3.31 (m, 2H), 3.16-3.08 (m, 2H), 2.98-2.90 (m, 2H), 2.68-2.67 (m, 1H), 2.45-2.35 (m, 4H), 2.32-2.28 (m, 4H), 2.24 (dd, J = 16.5, 9.0 Hz, 1H), 2.18-2.03 (m, 1H), 1.79-1.74 (m, 1H), 1.69-1.66 (m, 1H), 1.46-1.23 (m, 1H). 13C NMR (126 MHz, CDCl3) δ 175.8, 174.9, 173.4, 173.3, 170.0, 168.8, 153.6, 152.9, 138.9, 138.3, 138.1, 136.7, 129.6, 129.4, 129.0, 128.9, 128.8, 128.4, 127.8, 127.4, 127.0, 126.8, 126.7, 63.2, 59.5, 49.8, 47.3, 47.1, 46.7, 41.0, 40.3, 34.9, 34.7, 34.5, 34.3, 32.7, 32.5, 28.9, 27.9, 23.7, 23.6, 23.4, 22.2 ppm. HRMS (ESI) m/z calculated [M+H]+: 490.25611; found [M+H]+: 490.25581. 1-Benzyl-9'-(4-chlorobenzyl)-18'-phenethyl-6',7',12',13',14',15',17',18'-octahydro-5'H- spiro[piperidine-4,10'-tetrazolo[1,5-a][1,4,9,12]tetraazacyclohexadecine]-8',11',16'(9'H)-trione (9.13):
The product was obtained as a white solid (19%, 0.132 g, mp 142-144 oC). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 7.20-7.14 (m, 4H), 7.14-7.08 (m, 7H), 7.02 (dd, J = 11.5, 7.0 Hz, 3H), 6.38 (bs, 1H), 5.45-5.41 (m, 1H), 4.51 (s, 2H), 4.16-4.04 (m, 1H), 4.04- 3.92 (m, 1H), 3.42-3.29 (m, 3H), 3.19-3.05 (m, 1H), 2.61- 2.53 (m, 4H), 2.49-2.36 (m, 2H), 2.30 (d, J = 12.5 Hz, 2H), 2.28-2.08 (m, 8H), 2.04-1.93 (m, 2H), 1.94-1.76 (m, 4H), 1.76-1.63 (m, 2H). 13C NMR (126 MHz, CDCl3) δ 173.7, 173.6, 154.7, 140.4, 136.6, 133.6, 129.5, 129.3, 128.7, 128.5, 128.5, 127.5, 126.5, 68.3, 64.9, 62.8, 62.3, 53.8, 53.3, 50.5, 49.9, 49.2, 49.0, 47.4, 46.7, 43.5, 42.3, 42.0, 39.5, 35.5, 33.7, 32.9, 32.2, 30.9, 30.1, 25.4, 24.6, 21.0, 19.1 ppm. HRMS (ESI) m/z calculated [M+H]+: 697.33759; found [M+H]+: 697.33764.
11-Benzyl-12-isopropyl-6,7,8,9,11,12,14,15,16,17,19,20-dodecahydrotetrazolo[1,5-a][1,4,9,12]tetraazacycloo ctadecine-10,13,18(5H)-trione (9.14):
The product was obtained as a white solid (32%, 0.150 g, mp 138-139 oC). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 7.31 (bs, 1H), 7.27 (d, J = 7 Hz, 1H), 7.20- 7.18 (m, 2H), 7.16-7.11 (m, 2H), 6.72 (t, J = 6.0 Hz, 1H), 4.90 (dd, J = 6.5 Hz, 1H), 4.69 (dd, J = 5.5 Hz, 1H), 4.59 (d, J = 17.5 Hz, 1H), 4.48 (d, J = 17.0 Hz, 1H), 4.39 (t, J = 7.3 Hz, 1H), 4.21 (t, J = 7.0 Hz, 2H), 4.16 (d, J = 11.5 Hz, 1H), 3.32 (m, 1H), 3.20 (m, 1H), 2.51-2.41 (m, 1H), 2.32 (t, J = 6.0 Hz, 2H), 2.22 (m, 2H), 2.17-2.00 (m, 1H), 1.84-1.74 (m, 4H), 1.61 (m, 1H), 1.48-1.35 (m, 1H), 1.08-0.97 (m, 1H), 0.97-0.90 (dd, J = 6.0 Hz, 3H), 0.91-0.82 (m, 1H), 0.79 (dd, J = 3.5 Hz, 3H). 13C NMR (126 MHz, CDCl3) δ 175.2, 173.4, 173.2, 170.7, 168.5, 152.9, 152.8, 138.6, 137.3, 128.7, 127.9, 127.8, 127.5, 126.8, 126.5, 67.6, 66.3, 47.2, 47.1, 40.7, 38.3, 34.6, 33.3, 32.9, 32.8, 32.6, 31.6, 28.9, 28.6, 27.3, 26.9, 25.0, 24.5, 24.0, 23.3, 22.3, 20.3, 19.9, 19.4, 18.6 ppm. HRMS (ESI) m/z calculated [M+H]+: 470.28741; found [M+H]+: 470.28711.
182
11-Benzyl-12-isobutyl-6,7,8,9,11,12,14,15,16,17,19,20-dodecahydrotetrazolo[1,5-a] [1,4,9,12]tetraazacycloocta decine-10,13,18(5H)-trione (9.15):
The product was obtained as a white solid (31%, 0.149 g, mp 214-215 oC). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 7.59 (t, J = 6.0, 1H), 7.28 (t, J = 7.3 Hz, 2H), 7.22 (d, J = 7.0 Hz, 1H), 7.19 (d, J = 4.0 Hz, 1H), 7.11 (d, J = 7.5 Hz, 2H), 7.03 (dd, J = 4.0 Hz, 1H), 4.94 (dd, J = 7.0 Hz, 1H), 4.86 (t, J = 7.3 Hz, 1H), 4.62 (dd, J = 5.5 Hz, 1H), 4.55 (d, J = 11.0 Hz, 2H), 4.50 (s, 1H), 4.41 (t, J = 7.0 Hz, 1H), 4.27 (t, J = 6.7 Hz, 2H), 3.55-3.44 (m, 1H), 3.09- 2.99 (m, 1H), 2.37-2.2.31 (m, 2H), 2.33-2.23 (m, 2H), 2.23-2.14 (m, 2H), 2.03-1.75 (m, 6H), 1.71-1.65 (m, 1H), 1.49-1.37 (m, 2H), 1.31-1.28 (m, 1H), 1.26-1.15 (m, 1H), 1.11-1.01 (m, 1H), 0.86 (d, J = 6.5 Hz, 1H), 0.82 (d, J = 6.5 Hz, 3H), 0.76 (d, J = 6.5 Hz, 3H), 0.71 (d, J = 6.5 Hz, 1H). 13C NMR (126 MHz, CDCl3) δ 175.1, 174.9, 173.5, 173.4, 171.4, 169.5, 153.1, 152.9, 138.9, 137.8, 128.9, 128.3, 128.0, 127.5, 126.9, 126.2, 68.5, 68.2, 59.0, 57.1, 49.0, 47.4, 47.2, 40.6, 38.6, 37.3, 34.5, 33.4, 33.0, 32.7, 32.5, 31.6, 29.1, 28.9, 25.5, 25.3, 25.3, 24.9, 24.8, 24.2, 23.7, 23.0, 22.9, 22.5, 22.3 ppm. HRMS (ESI) m/z calculated [M+H]+: 484.30306; found [M+H]+: 484.30301. 11-(2,4-Dichlorobenzyl)-12-isobutyl-6,7,8,9,11,12,14,15,16,17,19,20-dodecahydro tetrazolo[1,5-a][1,4,9,12]tetraazacyclooctadecine-10,13,18(5H)-trione (9.16):
The product was obtained as a white solid (20%, 0.110 g, mp 147-149 oC). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 7.81 (t, J = 5.8, 1H), 7.35 (s, 1H), 7.21 (d, J = 8.5, 1H), 7.05 (d, J = 8.5 1H), 4.92 (dd, J = 15.5, 6.5 Hz, 1H), 4.77-4.72 (m, 1H), 4.63 (dd, J = 16.0, 5.5 Hz, 1H), 4.56 (s, 1H), 4.40-4.27 (m, 2H), 3.57-3.45 (m, 1H), 3.11- 3.02 (m, 1H), 2.32-2.19 (m, 3H), 2.09-2.05 (m, 1H), 2.03- 1.86 (m, 2H), 1.88-1.74 (m, 2H), 1.68-1.65 (m, 2H), 1.58- 1.55 (m, 1H), 1.52-1.39 (m, 1H), 1.40-1.27 (m, 2H), 1.28- 1.12 (m, 2H), 1.06-1.01 (m, 1H), 0.92-0.74 (m, 6H). 13C NMR (126 MHz, CDCl3) δ 174.9, 173.5, 171.0, 152.8, 133.8, 133.6, 132.8, 129.6, 127.9, 127.3, 56.8, 47 .1, 46.4, 38.6, 37.0, 33.3, 32.5, 31.6, 28.9, 25.3, 25.2, 24.8, 23.9, 23.0, 22.2 ppm. HRMS (ESI) m/z calculated [M+H]+: 552.22512; found [M+H]+: 522.22535. 12-Isobutyl-11-propyl-6,7,8,9,11,12,14,15,16,17,19,20-dodecahydrotetrazolo[1,5-a][1,4,9,12]tetraazacyclo octadecine-10,13,18(5H)-trione (9.17):
The product was obtained as a white solid (20%, 0.087 g, mp 129-131 oC). 1H NMR (500 MHz, CDCl3) δ 7.47 (t, J = 6.0 Hz, 1H), 7.00 (t, J = 4.5 Hz, 1H), 4.93 (dd, J = 16.0, 7.0 Hz, 1H), 4.76 (t, J = 7.3 Hz, 1H), 4.61 (dd, J = 16.0, 5.5 Hz, 1H), 4.37-4.25 (m, 2H), 3.50- 3.39 (m, 1H), 3.19-3.04 (m, 2H), 2.42-2.36 (m, 1H), 2.32-2.29 (m, 1H), 2.29-2.24 (m, 2H), 2.08-1.89 (m, 2H), 1.88-1.71 (m, 4H), 1.59-1.55. (m, 1H), 1.58-1.39 (m, 4H), 1.31-1.11 (m, 2H), 0.89 (dd, J = 6.5 Hz, 6H), 0.81 (t, J = 7.3 Hz, 3H). 13C NMR (126 MHz, CDCl3) δ 174.2, 173.6, 172.1, 153.1, 57.0, 48.0, 47.5, 38.8, 37.4, 33.5, 32.6, 31.8, 29.41, 25.7, 25.3, 24.8, 24.3, 23.7, 23.1, 22.9, 11.7 ppm. HRMS (ESI) m/z calculated [M+H]+: 436.30306; found [M+H]+: 436.30244.
183 1-Benzyl-11'-(4-chlorobenzyl)-6',7',8',9',14',15',16',17' ,19',20'-decahydro-5'H-spiro-[piperidine-4,12'-tetrazolo[1,5-a][1,4,9,12]tetraazacyclooctadecine]-10',13',18' (11'H)-trione (9.18).
The product was obtained as a white solid (21%, 0.130 g, mp 210-212 oC). 1H NMR (500 MHz, CDCl3) δ 7.90 (s, 1H), 7.32 (d, J = 8.4 Hz, 2H), 7.27-7.24 (m, 3H), 7.20 (d, J = 7.0 Hz, 4H), 6.29 (s, 1H), 4.86 (d, J = 5.7 Hz, 2H), 4.54 (s, 2H), 4.27 (t, J = 6.5 Hz, 2H), 3.41 (bs, 4H), 2.66 (bs, 2H), 2.43 (t, J = 7.1 Hz, 2H), 2.33 (d, J = 13.1 Hz, 2H), 2.18 (bs, 4H), 1.97-1.78 (m, 6H), 1.40 (bs, 2H), 1.07 (bs, 2H). 13C NMR (126 MHz, CDCl3) δ 175.1, 174.3, 173.7, 152.7, 136.8, 133.5, 129.4, 128.5, 127.3, 64.6, 63.0, 50.2, 47.4, 47.4, 38.8, 34.2, 33.3, 32.4, 32.0, 28.9, 26.5, 25.4, 24.2 ppm. HRMS (ESI) m/z calculated [M+H]+: 621.30629; found [M+H]+: 621.30624.
11-(4-Chlorobenzyl)-12-(2-(methylthio)ethyl)-6,7,8,9,11,12,14,15,16,17,19,20-dodeca-hydrotetra-zolo[1,5-a][1,4,9,12]tetraazacyclooctadecine-10,13,18(5H)-trione (9.19):
The product was obtained as a white solid (22%, 0.118 g, mp 180-181 oC); mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 8.04 (t, J = 6.0 Hz, 1H), 7.73 (t, J = 6.0 Hz, 1H), 7.35 (d, J = 8.5 Hz, 2H), 7.33 (s, 1H), 7.17 (d, J = 8.0 Hz, 2H), 7.13 (dd, J = 6.5, 4.5 Hz, 1H), 5.04 (dd, J = 15.5, 7.0 Hz, 1H), 4.98 (dd, J = 8.0, 6.0 Hz, 1H), 4.90 (dd, J = 15.5, 6.5 Hz, 1H), 4.73-4.63 (m, 2H), 4.65-4.56 (m, 2H), 4.53-4.45 (m, 2H), 4.38 (t, J = 6.8, 2H), 3.59-3.49 (m, 1H), 3.27-3.19 (m, 1H), 3.19-3.10 (m, 1H), 2.92-2.82 (m, 1H), 2.77-2.72 (m, 1H), 2.68-2.56 (m, 2H), 2.57-2.47 (m, 2H), 2.47-2.39 (m, 4H), 2.38-2.28 (m, 4H), 2.21-2.15 (m, 1H), 2.08 (s, 3H), 2.05 (s, 3H), 2.03-1.99 (m, 2H), 1.95-1.85 (m, 2H), 1.85-1.67 (m, 4H), 1.64-1.57 (m, 1H), 1.56 - 1.48 (m, 1H), 1.35 - 1.29 (m, 1H), 1.25 – 1.11 (m, 1H) ppm. 13C NMR (126 MHz, CDCl3) δ 175.3, 175.1, 173.9, 173.8, 171.0, 169.1, 153.2, 153.1, 137.8, 136.3, 133.9, 133.1, 130.2, 129.5, 128.7, 128.0, 58.9, 58.1, 49.3, 48.6, 47.7, 47.6, 46.2, 41.3, 39.2, 39.1, 35.1, 33.8, 33.2, 33.0, 32.1, 31.5, 29.4, 29.2, 28.4, 28.3, 25.7, 25.7, 25.1, 24.3, 23.8, 22.8, 16.0, 15.8 ppm. HRMS (ESI) m/z calculated [M+H]+: 536.22051; found: [M+H]+: 534.22055. 11'-(4-Fluorobenzyl)-1-methyl-20'-phenethyl-6',7',8',9',14', 15',16',17',19',20'-deca-hydro-5'H-spiro[piperidine-4,12'-tetrazolo[1,5-a][1,4,9,12]tetraaza cyclooctadecine]-10',13',18' (11'H)-trione (9.20):
The product was obtained as a white solid (25%, 0.158 g, mp 120-122 oC). A mixture of rotamers is observed; 1H NMR (500 MHz, CDCl3) δ 8.18 (d, J = 8.0 Hz, 1H), 7.76 (d, J = 7.5 Hz, 1H), 7.51 (d, J = 7.5 Hz, 1H), 7.36 (m, 1H), 7.29-7.25 (m, 2H), 7.25-7.18 (m, 4H), 7.14 (dd, J = 17.5, 7.0 Hz, 4H), 6.88 (t, J = 8.3 Hz, 2H), 5.40-5.28 (m, 1H), 4.62 (s, 2H), 4.28-4.12 (m, 2H), 3.41-3.10 (m, 6H), 2.99 (t, J = 11.5 Hz, 1H), 2.72 (t, J = 7.5 Hz, 2H), 2.58 (s, 3H), 2.50-2.23 (m, 8H), 2.21-2.08 (m, 2H), 1.97-1.92 (m, 1H), 1.89-1.80 (m, 1H), 1.79-1.77 (m, 2H), 1.64-1.42 (m, 2H),
