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

2-Methyl benzothiazoles are widely used as key precursors for dyes, photosensitizers, and fluorescent markers. Thus, they are demanded in multigram and even kilogram quantities. We propose a scalable single-step procedure for producing 2-alkyl-substituted benzothiazoles from the corresponding bis-(2-nitrophenyl)-disulfide commercial, technical-grade quality. The reaction scope looks promising; substrates containing various substituents, including carboxylic and ester groups, were introduced. The reaction conditions were carefully optimized according to reducing agents (diverse sodium salts), solvents, ratio, and reaction time. This led to the acquisition of target products in up to 350 g quantities in a single run.