Quinazolino-3,l-benzoxazines

Quinazolino-3,1-benzoxazines Quinaz.olino[3,2-a]3,l-benzoxaz.ines 

2-Isocyanatobenzoyl chloride reacted with isatoic anhydride (76JOC2728) or nitromethane in benzene [83IJC(B)485] to yield 5H,12H-quinazolino[3,2-a]3,1 -benzoxazine-5,12-dione (540) (76JOC2728). Cyclodehydration of 3-(2-carboxyphenyl)quinazoline-2,4(l//,3/f)-dione (575) (66ACH77 67MI1) also afforded the same compound (540). 

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