Solid-supported syntheses of 3-thio-1,2,4-triazoles

Discovery, synthesis, and structure–activity studies of tetrazole based growth hormone secretagogues

A novel class of Growth Hormone Secretagogues (GHS), based on a tetrazole template, has been discovered. In vitro SAR and in vivo potency within this new class of GHS are described. The tetrazole 9q exhibits good oral bioavailability in rats and dogs as well as efficacy following an oral 10 mg/kg dose in dogs. Solution and solid phase protocols for the synthesis of tetrazole based GHS have been developed.

Organic azides: an exploding diversity of a unique class of compounds

Since the discovery of organic azides by Peter Griess more than 140 years ago, numerous syntheses of these energy-rich molecules have been developed. In more recent times in particular, completely new perspectives have been developed for their use in peptide chemistry, combinatorial chemistry, and heterocyclic synthesis. Organic azides have assumed an important position at the interface between chemistry, biology, medicine, and materials science. In this Review, the fundamental characteristics of azide chemistry and current developments are presented. The focus will be placed on cycloadditions (Huisgen reaction), aza ylide chemistry, and the synthesis of heterocycles. Further reactions such as the aza-Wittig reaction, the Sundberg rearrangement, the Staudinger ligation, the Boyer and Boyer-Aubé rearrangements, the Curtius rearrangement, the Schmidt rearrangement, and the Hemetsberger rearrangement bear witness to the versatility of modern azide chemistry.

3-Thio-1,2,4-triazoles, novel somatostatin sst2/sst5 agonists

Novel 3-thio-1,2,4-triazoles have been obtained via a solution-phase parallel synthesis strategy, affording potent non-peptidic human somatostatin receptor subtypes 2 and 5 agonists.

Solid phase synthesis and application of trisubstituted thioureas

Resin-bound amines 1a-e condense with isothiocyanates to give thiourea resins 2a-i. Resins 2a-g subsequently react with iodomethane followed by cleavage affording S-methyl isothioureas 4a-g, and resins 2a-b,h-i react with acyl chlorides to afford N-acylated thioureas 6a-d. N-Acylthioureas 8a-f (R(2) = H) were prepared directly from resin-bound amines 1a-d with acyl isothiocyanates. N-Acylthioureas 8a-d,f(R(2) = H) were used for the preparation of S-methyl-N-acylisothioureas 10a-e. Alkylation was performed using methyl iodide. Resin-bound S-methyl-N-acylisothioureas 10a,b,d are converted by an action of hydrazines into 3-amino-1,2,4-triazoles 13a-d. Condensation of resins 8a-e (R(2) = H) with 2-bromoacetophenones in the presence of TEA affords thiazoles 15 a-e. All transformations proceeded in high yields and gave products of good purities.

Synthesis of triazole-Tethered pyrrolidine libraries: novel ECE inhibitors

The solid-phase synthesis of substituted 1,2,4-triazoles tethered to a 4-mercaptopyrrolidine core 1 is described. This novel class of non-peptidic, Zn(2+) metallo-protease inhibitors was found to have inhibitory activity for the endothelin converting enzyme (ECE-1). The SAR of the substitution pattern in 1 is discussed.

Traceless solid-phase synthesis of 1,2,4-triazoles using a novel amine resin

[reaction: see text]. A solid-phase route to 5-aryl-3-arylthiomethyl-1,2,4-triazoles has been developed that permits the incorporation of two elements of diversity. The heterocycle was constructed upon a novel 4-benzyloxy-2-methoxybenzylamine (BOMBA) resin, from which traceless cleavage could be effected with dilute TFA. A library of 96 triazoles was produced with an average yield of 26% (84% yield per step) and an average purity of 80%. In a direct comparison, the new BOMBA resin proved to be markedly superior to Rink Amide resin for this application.