Practical One Pot Synthesis of 2-Alkyl-substituted Benzothiazoles from Bis-(2-nitrophenyl)-disulfides.

2-Methyl benzothiazoles are widely used as key precursor for dyes, photosensitizers and fluorescent markers. Therefore, they are demanded in multigram and even kilogram amounts. Hereby, we propose a scalable single-step procedure for production of 2-alkylsubstituted benzothiazoles from corresponding bis-(2-nitrophenyl)-disulfides. Substrates containing various substituents including carboxylic and ester groups were introduced into reaction. Different sodium salts were tested as reducing agents, extensive optimization was performed. The products were obtained in the amounts of up to 350 g in a single run.