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.