[C:1]([OH:10])(=[O:9])[C:2]1[C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[NH2:4].C(=O)([O-])[O-].[Na+].[Na+].[S:17](Cl)([C:20]1[CH:26]=[CH:25][C:23]([CH3:24])=[CH:22][CH:21]=1)(=[O:19])=[O:18]>O>[S:17]([NH:4][C:3]1[C:2](=[CH:8][CH:7]=[CH:6][CH:5]=1)[C:1]([OH:10])=[O:9])([C:20]1[CH:26]=[CH:25][C:23]([CH3:24])=[CH:22][CH:21]=1)(=[O:19])=[O:18]In a 1 L reaction flask equipped with a condenser, 34.25 g (0.25 mol) of anthranilic acid, 411 g of water and 63.59 g (0.6 mol) of sodium carbonate were heated. The resulting reaction solution was maintained at an inner temperature of 78° C. for 30 minutes and then cooled to 67° C., and 57.2 g (0.3 mol) of tosyl chloride was added in two portions. The reaction solution gradually generated heat upon addition of tosyl chloride and turned homogeneous at 78° C. The reaction solution was aged at 80° C. for 1 hour. Crystals started to separate out in the first ten or so minutes of the aging. The completion of the reaction was confirmed by liquid chromatography, and the reaction solution was carefully neutralized with concentrated hydrochloric acid and allowed to cool. The crystals were collected by filtration at room temperature and washed with 100 ml of dilute hydrochloric acid at pH 3 and with 125 ml of water. Recrystallization from 247 g of n-propanol afforded 56.97 g of tosylanthranilic acid in a 78.3% yield.
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