Ring rearrangements and reactivity of 3-((4-oxo-4H-chromen-3-yl)methylene)-4-phenyl-1H-[1,5]benzodiazepin-2(3H)-one toward some nucleophiles

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-chromenylbenzodiazepino[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.