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.

reaction of 5-phenyl tetrazole with ethyl chloroacetate to form ethyl (5-phenyl-1h-tetrazol-1-yl) acetate (1). compound 1 react with hydrazine hydrate in ethanol yield 2-(5-phenyl-1h-tetrazol-1-yl) acetohydrazide (2). the condensation of (2) with various aldehydes yield the corresponding substituted n'-[-arylidene]-2-(5-phenyl-1h-tetrazol-1-yl) acetohydrazide (3a- j). the compounds obtaine...

Three novel tetrazole-based frustrated magnets, namely, Co3(OH)2(3-ptz)2(SO4)(H2O)4 (1), Co2(OH)(tzba)(H2O)4 (2) and [Co(OH)(tta)] (3) (3-ptz = 5-(3-pyridyl) tetrazole, H2tzba = 4-(1H-tetrazol-5-yl) benzoic acid, Htta = 1H-tetrazole) were hydrothermal synthesized and magnetically characterized. Compound 1 is a 2D (4,4) layered structure assembled by sulfate capped triangular [Co3(μ3-OH)(μ3-SO4)...

A model for computing image ow in image sequences containing a very wide range of instantaneous ows is proposed. This model integrates the spatio-temporal image derivatives from multiple temporal scales to provide both reliable and accurate instantaneous ow estimates. The integration employs robust regression and automatic scale weighting in a generalized brightness constancy framework. In addi...

To evaluate the possibility of introducing azole nucleosides as building blocks for metal-mediated base pairs in artificial oligonucleotides, imidazole nucleoside, 1,2,4-triazole nucleoside and tetrazole nucleoside have been synthesized and characterized. The X-ray crystal structures of p-toluoyl-protected 1,2,4-triazole and tetrazole nucleosides are reported. Contrary to the situation primaril...

The title compound, PNU-97018 [systemic name: 2-butyl-3,6,7,8,9,11-hexahydro-6,9-dimethyl-3-([2'-(2H-tetrazol-5-yl)[1,1'-biphenyl]-4-yl]methyl)-6,9-ethano-4H-imidazo[4,5-d]-pyridazino[1,2-a]pyridazin-4-one] is a newly developed angiotensin II receptor antagonist. The compound and its methanolate and ethanolate were characterized by X-ray crystallography and thermal analysis. The methanolate and...

Treatment of primary or secondary alcohols with 1-phenyl-1(H)-tetrazole-5-thiol and [Me(2)NCHSEt](+) BF(4)(-) leads directly and cleanly to 1-phenyl-1(H)-tetrazol-5-yl sulfides.

Energetic ionic salts of azotetrazolate (AT), iminobis(5-tetrazolate) (IBT) and 5, 5'-bis(tetrazole) (BT) were synthesized; 1-methyl-4-aminotriazolium azotetrazolate has a layered structure and exhibits a heat of formation of +4360 kJ kg(-1).

The first examples of anionic Ir(iii) bis-tetrazolate complexes and their combination with a cationic Ir(iii)tetrazole derivative forming "fully tetrazolate" Ir(iii) based soft salts as O2-sensitive white emitters are described herein.

A supramolecular hydrogel formed by dipeptide Gly-Ala linked with biphenyl-substituted tetrazole serves not only as a 3D matrix for live cells, but also as a carrier to deliver microRNA into the encapsulated cells.