G. Roma, A. Balbi, A. Ermili
Aug 1, 1983
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Journal
Il Farmaco; edizione scientifica
Abstract
The reaction of 4-(dialkylamino)-1,3-dihydro-2H-1,5-benzodiazepin-2-ones (I a-c) with N,N-dimethylformamide in the presence of phosphorus pentachloride at room temperature gave rise to the formation of 4-(dialkylamino)-3-[(dimethylamino)methylene]-1,3-dihydro-2H-1,5-benzodiazepin- 2-ones (IX a-c) which were useful starting materials to achieve the synthesis of tricyclic 1,5-benzodiazepine derivatives. Actually (IX a), selected for the smallest steric hindrance of the 4-dialkylamino substituent, by reaction with hydrazines afforded pyrazolo[3,4-b][1,5]benzodiazepine derivatives whereas reaction with guanidine or amidines gave 5H-pyrimido-[4,5-b][1,5]benzodiazepine derivatives. The structure of isomeric N-methyl-pyrazoles (X c) and (XI a) and of N-phenylpyrazole (X b) were elucidated by comparison with compounds prepared by unequivocal chemical methods. Pharmacological evaluation of some of the products showed only generic CNS depressant activity.