Thermal reactions of aryl azides with 1,2,3-benzothiadiazole

Abstract

Thermolysis of phenyl azide in the presence of 1,2,3-benzothiadiazole (1) affords phenothiazine (2), thianthrene (3), and dibenzo[c,e]-o-dithiin (4) together with aniline and traces of azobenzene, while p-nitrophenyl azide gives no phenothiazine derivative and decreased yields of (3) and (4), whereas increased yields of (3) and (4) are observed with p-methoxyphenyl azide, together with small amounts of the phenothiazine derivative, evidence in favour of an initial attack on the sulphur of (1) by triplet arylnitrenes is presented.