2-(methylamino)benzenethiol

Conditions: temp:5.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4.5 g (=0.032 m) of 2-(methylamino)-thiophenol, 6 g of triethylbenzylammonium chloride, and 11.20 g of sodium hydrogen carbonate were added to 120 ml of chloroform. The resulting suspension was cooled to 5° C., and then a solution of 10.88 g of 2,6-dibromohexanoyl bromide in 20 ml of chloroform was added dropwise so slowly that the temperature did not exceed 5° C. 20 minutes were required for the addition. The reaction mixture was then allowed to warm to room temperature and was subsequently heated under reflux for 4 hours. The reaction mixture was worked up by cooling and filtering it. The chloroform phase was washed, dried over sodium sulfate, and the solvent was distilled off. The 2-(4-bromobutyl)-4-methyl-2H-1,4-benzothiazine-3(4H)-one which formed was isolated from the remaining residue by fractional column chromatography. 2.78 g of white crystals having a melting point of 116° C. were obtained. did not exceed 5° C 20 minutes were required for the addition to warm to room temperature was subsequently heated under reflux for 4 hours by cooling filtering it The chloroform phase was washed dried over sodium sulfate the solvent was distilled off