The ring-closure reactions of N-(3,4-dimethoxyphenylthiomethyl)-2-nitrobenzamide derivatives 5a,b with phosphoryl chloride gave 4-(2-nitrophenyl)-2H-1,3-benzothiazine derivatives 7a,b, which on reduction yielded 4-(2'-aminophenyl)-3,4-dihydro-2H-1,3-benzothiazines 8a,b. Reaction of these compounds with phosgene led to a new heterocyclic ring system, 6-H,8H-quinazolino[3,4-c][1,3]benzothiazine derivatives 9a,b. The structures of the title compounds were proved via their ir and nmr (1H, 13C) spectra.
|Number of pages||5|
|Journal||Mathematical Problems in Engineering|
|Publication status||Published - Oct 1 1992|
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