An efficient synthesis of the angiotensin-II inhibitor valsartan (Diovan®) is presented. Directed ortho-metalation of 5-phenyl-1-trityl-1H-tetrazole (6) and its Negishi coupling with aryl bromide 5 are the key steps of the synthesis. This method overcomes many of the drawbacks associated with previously reported syntheses.

During the process development for multigram-scale synthesis of olmesartan medoxomil (OM), two principal regioisomeric process-related impurities were observed along with the final active pharmaceutical ingredient (API). The impurities were identified as N-1- and N-2-(5-methyl-2-oxo-1,3-dioxolen-4-yl)methyl derivatives of OM. Both compounds, of which N-2 isomer of olmesartan dimedoxomil is a no...

Four cationic ruthenium(II) complexes with the formula [Ru(eta(5)-C(5)H(5))(PPh(3))(2)](+), with L = 5-phenyl-1H-tetrazole (TzH) 1, imidazole (ImH) 2, benzo[1,2-b;4,3-b'] dithio-phen-2-carbonitrile (Bzt) 3, and [5-(2-thiophen-2-yl)-vinyl]-thiophene-2-carbonitrile] (Tvt) 4 were prepared and characterized in view to evaluate their potentialities as antitumor agents. Studies by Circular Dichroism ...

The reagent 2-iminothiolane (2-IT) is used to introduce thiol groups into proteins and peptides by reactions of their amino groups. In this study, we report that the thiol adduct initially formed by the reaction of an amine with 2-IT (a 4-mercaptobutyramidine) is unstable and decays by a first-order process to a nonthiol product (an N-substituted 2-iminothiolane) with the loss of ammonia. The t...

An important direction of modern pharmaceutical science is the creation promising biologically active compounds, which in hands scientists can be transformed into effective medicinal products. Heterocyclic compounds are undisputed leader solving this problem. A well-known fact and a well-founded approach to achieving desired pharmacological effect combination different heterocyclic fragments st...

5-Furan-2-yl[1,3,4]oxadiazole-2-thiol (Ia) and 5-furan-2-yl-4H-[1,2,4]-triazole-3-thiol (Ib) were synthesized from furan-2-carboxylic acid hydrazide. Mannich bases and methyl derivatives were then prepared. The structures of the synthesized compounds were confirmed by elemental analyses, IR and (1)H-NMR spectra. Their thiol-thione tautomeric equilibrium is described.

The aim of the work was to study antioxidant activity 4-R-3- (morpholinomethyl)-4H-1,2,4-triazole-5-thioles and their alkyl derivatives in vitro using method non-enzymatic initiation lipid peroxidation. Among 45 compounds studied, 8 showed varying degrees AOA. most pronounced AOA has 4-amino-3-(morpholinomethyl)-4H-1,2,4-triazole-5-thiol. It found that cases introduction alkyl-derivatives 4-R-3...