Propionitrile → 5-Propylamino-3-[methyl(methylsulfonyl)amino]benzoic acid

Participants

Reaction Conditions

Reaction Steps

To a mixture of methyl 3-[methyl(methylsulfonyl)amino]-5-nitrobenzoate obtained in Reference Example 92.88 g (10 mmol), 10% Pd/C (50% wet) (0.60 g), methanol (30 mL), propionitrile (10 mL) and H2O (10 mL) was added ammonium formate 12.6 g (200 mmol) and the mixture was stirred at 50° C. for 5 hours. The reaction solution was filtered on Celite and the solvent was evaporated and the mixture was dissolved in ethyl acetate, washed with water and dried on magnesium sulfate. The solvent was evaporated and the residue was purified by a column chromatography on silica gel (eluted with chloroform). The resulting methyl ester 1.90 g (6.33 mmol) was dissolved in methanol (20 mL) and thereto was added 2.5N aqueous sodium hydroxide solution 7.60 mL (18.99 mmol) and the mixture was stirred at 40° C. for 1 hour. To the reaction solution was added 5% aqueous citrate and the mixture was extracted with ethyl acetate and washed with 5% aqueous sodium chloride solution and dried on magnesium sulfate. The solvent was evaporated and the residue was recrystallized from n-hexane to give 1.28 g (4.3 mmol) of the title compound (yield: 43%).

Provenance & Evidence