Synthesis of Heterocycles Based on Products of Anion Arylation of Unsaturated Compounds. 5. Reaction of 2-Aryl-1,4-benzoquinones with Thiourea

2-Aryl-1,4-benzoquinones, that can be obtained by arylation of quinone by arenediazonium salts, regioselectively react with thiourea in acid medium to form 7-aryl-5-hydroxy-1,3-benzoxathiol-2-ones. In the presence of excess arylquinones at room temperature, 2-amino-6-hydroxybenzothiazoles are formed in the same reaction.