Synthesis of new Di-, Tetra-, and hexahydropyrazolo[3,4-e][1,4]diazepine derivatives

5-Amino-N-(2,2-dialkoxyethyl)pyrazole-4-carboxamides in the synthesis of 7-sulfanyl-5,6,7,8-tetrahydro-1H-pyrazolo[3,4-e][1,4]diazepin-4-ones

“…[1]) an oily mixture was isolated which according to GC-MS data contained 64% of compound ІІа and 20% of the product of its intermolecular condensation VII. The possibility of the formation of the latter is in agreement with the description [14] of a similar conversion in acid conditions of 4-amino-[N-(2,2diethoxyethyl)]-3-phenylisoxazole-5-carboxamide.…”

“…Recently [1] by intramolecular cyclocondensation of 5-amino-N-(2,2-diethoxyethyl)pyrazole-4-carboxamides Іа-Id in acid medium we synthesized 7hydroxy-5,6,7,8-tetrahydro-1Н-pyrazolo [3,4-e] [1,4]diazepin-4-ones ІIа-IId, singular polyfunctional compounds containing in the diazepine ring fragments convenient for further modification: carbamoyl and αaminohydroxy moieties.…”

“…The possibility to apply this cyclization to the synthesis of the other 7-substituted pyrazolodiazepines depends on the preparative accessibility of compounds I. The described procedure of their preparation [1] by the hydrolytic cleavage of 5-(2,2-diethoxyethyl)pyrazolo [3,4-d]pyrimidin-4-ones turned out to be applicable only to the simplest 1-alkyl(aryl)-substituted compounds II. It was however impossible to obtain by this method 1-unsubstituted or unstable in alkaline media functionalized 1-R-analogs.…”

“…It was however impossible to obtain by this method 1-unsubstituted or unstable in alkaline media functionalized 1-R-analogs. Taking into account that nowadays the modification of versatile indole [7], 1,2,3-oxadizole [8,9], 1,2,3triazole [10], benzothiazole 11], pyrimidine [12,13] compounds with sulfanyl groups has found wide application to the rational design of scaffolds aiming at the search for biologically active substances we regard as an important task the introduction of sulfanyl moieties in the structure of biophore pyrazolo[3,4-e]- [1,4]diazepine system. Diazepines ІІа-IId are convenient objects in this respect for their hydroxy group can be utilized for the replacement by more nucleophilic residues of thiols or thiophenols.…”

2-amino-5-(4-chloro-1h-imidazol-5-yl)-1,3,4-thiadiazoles: synthesis, pyrimidoannulation and the bactericidal activity

“…Автори [25,26] розробили препаративно зруч-ний метод синтезу 7-заміщених піразоло [1,4]діа-зепін-4-онів 11 та 12, який базується на викорис-танні синтетично доступних піразоло [3,4-d]піри-мідин-4-онів 13. Показано, що їх взаємодія з діаце-талем бромоацетальдегіду 14 або бромацетофе-нонами 15 в киплячому ацетонітрилі в присут-ності безводного К 2 СО 3 з високими виходами при-водить до відповідних 5-β-алкілфункціоналізова-них піразоло [3,4-…”