SYNTHESIS OF NOVEL 3-METHYL-6, 7-DIARYL-5,6,7,8-TETRAHYDRO-4H-ISOXAZOLO[4,5-d][1,3] DIAZEPINES

The synthesis of novel 3-methyl-6,7-diaryl-5,6,7,8-tetrahydro-4H-isoxazolo[4,5-d] [1,3] diazepine (6a-j) is described. A three component reaction of 3,5-dimethyl-4-nitroisoxazole 1, aromatic aldehyde 2 and substituted anilines 3 in ethanol using ceric ammonium nitrate (CAN) as Lewis acid catalyst yielded N-(2-(3-methyl-4-nitroisoxazol-5-yl)-1-phenylethyl) aniline (4a-j) by Mannich type reaction via a variety of aldimines generated in situ by reaction of aromatic aldehydes with aromatic amines. Compound 4 on reduction with SnCl2 in ethanol afforded 3methyl- 5-(2-phenyl-2-(phenylamino) ethyl) isoxazol-4-amines (5a-j). Cyclocondensation of 5 with formaline furnished novel 3-methyl-6,7-diaryl-5,6,7,8-tetrahydro-4H-isoxazolo[4,5-d] [1,3] diazepine (6a-j).