Water → HCID 13368505, compound

5-Chloro-3-methyl-2-benzothiazolinone (70.0 g) was added to a mixture of water (118 ml), ethanol (350 ml) and potassium hydroxide (78.6 g). The solution was refluxed with stirring for three hours. After the solvent was evaporated under reduced pressure, the residual oil was dissolved in water. After removal of insoluble yellow crystals by filtration, the filtrate was neutralized with 2N-acetic acid, then resulting oily substance was extracted with ethyl acetate. The extract was washed with water, dried (Na2SO4), and evaporated to give oily 4-chloro-2-methylaminothiophenol (59.7 g). To a solution of sodium hydroxide (14.0 g) in water (100 ml) was added 4-chloro-2-methylaminothiophenol (59.6 g) with stirring, and then was added dropwise a solution of chloroacetic acid (34.0 g) in water (50 ml) at 20-25° C., followed by heating almost to boiling for three hours.