Synthesis of 7-carboxyalkylthio-5,6,7,8-tetrahydro-1H-pyrazolo[3,4-e]diazepin-4-ones

Abstract

which is based on the intramolecular cyclization of 5-amino-N-(2,2-dialkyloxyethyl)pyrazole-4-carboxamides in the solution of formic acid with thioalkan carboxylic acids. The synthesis of the starting 5-aminopyrazolo-4-carboxamides has been performed by condensation of 2-cyano-N-(2,2-dimethoxy)-3-dimetylaminoacryl(croton) amides with alkyl hydrazines or hydrolytic cleavage of 5-(2,2-dietoxyethyl)-1,5-dihydropyrazolo-4Н-[3,4-d]pirimidin-4-ones. The scheme of this reaction proposed involves the intramolecular cyclocondensation with the initial formation of the corresponding 7-hydroxy-5,6,7,8-tetrahydropyrazolo[3,4-e] -гидрокси-5,6,7,8-тетрагидропиразоло[3,4-e]