N. Peet
1987
Citations
0
Influential Citations
9
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
Treatment of 2-isocyanatobenzoyl chloride (4) with 5-aminotetrazole (5-AT) gave 3-(5-tetrazolyl)quinazoline-2,4(1H,3H)-dione (1) directly. Treatment of 2-carbomethoxyphenyl isocyanate (5) with 5-AT gave 2-[((5-amino-1H-tetrazol-1-yl)carbonyl)amino]benzoic acid methyl ester (6) as a kinetic product, which was thermally isomerized to 2-[((1H-tetrazol-5-ylamino)carbonyl)amino]benzoic acid methyl ester (7), the thermodynamically more stable urea. Cyclization of 7 with polyphosphoric acid gave 2-(1H-tetrazol-5-ylamino)-4H-3,1-benzoxazin-4-one (2). Urea 6 was quite labile in solution, as shown by nmr, and readily reacted with methanol to give 2-[(methoxycarbonyl)amino]benzoic acid methyl ester (10).