title: [1,5-benzodiazepines. V. Synthesis of pyrazolo (3,4-b)(1,5)benzodiazepines and 5H-pyrimido(4,5-b)(1,5)benzodiazepines].
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.
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000138:chemical synthesis*; D001522:Behavior, Animal / Q000187:drug effects; D001569:Benzodiazepines; D055598:Chemical Phenomena; D002621:Chemistry; D051379:Mice; D011720:Pyrazoles / Q000138:chemical synthesis / Q000494:pharmacology; D011743:Pyrimidines / Q000138:chemical synthesis / Q000494:pharmacology
chemical_list: D014151:Anti-Anxiety Agents; D011720:Pyrazoles; D011743:Pyrimidines; D001569:Benzodiazepines
vernacular_title: Ricerche su 1,5-benzodiazepine. Nota V - Sintesi di derivati della pirazolo[3,4-b][1,5]benzodiazepina e della 5H-pirimido[4,5-b][1,5]benzodiazepina.