The reaction of thiourea with excess 1, 4-benzoquinones and l14-naphthoquinones in the presence of concentrated hydrochloric acid offers a convenient route for the synthesis of a variety of 2-amino-6-hydroxybenzothiazoles (3) and 2-amino-5-hydroxynaphtho [l, 2-d] thiazoles (15). These compounds could also be prepared by treating the corresponding S- (2, 5-dihydroxyphenyl) thiouronium chlorides (1) and S-(1, 4-dihydroxynaphthyl) ...
