Process for preparing 2-aminobenzothiazoles

摘要

Process for preparing 2-aminobenzothiazoles of the formula (1) <IMAGE> (1) in which R1 and R2 denote hydrogen or halogen atoms or alkylC1-C4, alkoxyC1-C4 or nitro groups, by reacting phenylthioureas of the formula (2) <IMAGE> (2) in which R1 and R2 have the abovementioned meanings, at temperatures of 20 DEG C. to 130 DEG C. in 70-100% strength sulfuric acid in the presence of catalytic amounts of bromine, hydrogen bromide, sodium bromide, potassium bromide or ammonium bromide which comprises carrying out the reaction in the presence of a finely divided solid which has a large specific surface area and is inert under the reaction conditions.