Water → Methyl 5-chloro-2-[(4-methylbenzene-1-sulfonyl)amino]benzoate

To a solution of methyl 5-chloroanthranilate (10.50 g (56.6 mmol) in pyridine (30 ml), p-toluenesulfonyl chloride (12.00 g (62.9 mmol)) was added with stirring at 5° C. The mixture was stirred at room temperature for 18 hours, and then, 200 ml of water was added to the resulting mixture. The crystals separated were filtered and washed to give 18.20 g (95%) of 4′-chloro-2′-methoxycarbonyl-p-toluenesulfonanilide as white crystals.