Abstract
Condensation of 4-phenyl-1H-[1,5]benzodiazepin-2(3H)-one (1) with 3-formylchromone (2) afforded a mixture of 3-(chromenylmethylene)[1,5]benzodiazepinone 3 and 14-chromenyl-benzodiazepino[2,3: 6,5] pyrano[2,3-b] benzodiazepine 4. Ring rearrangements of compound 3 with different nucleophilic reagents, such as potassium hydroxide and/or ammonium acetate led to rearrangement into pyranobenzodiazepine 5 and pyridobenzodiazepine 6, respectively. Treatment of compound 3 with hydrazine hydrate, hydroxylamine hydrochloride, malononitrile, cyanothioacetamide, 2-cyano-3,3-disufanylacrylonitrile, and/or 2-cyano-3-phenylamino-3-sufanylacrylonitrile, has been carried out at different conditions, leading to versatile heterocyclic substituted benzodiazepines at position 3, viz. pyrazole 8, isoxazole 9, pyridines 10 and 11, 1,3-dithiine 12, and 1,3-thiazine 13 derivatives. (C) 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.