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

Temperature

50 °C

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%).

1. filtrationThe reaction solution was filtered on Celite
2. customthe solvent was evaporated
3. dissolutionthe mixture was dissolved in ethyl acetate
4. washwashed with water
5. customdried on magnesium sulfate
6. customThe solvent was evaporated
7. customthe residue was purified by a column chromatography on silica gel (eluted with chloroform)
8. stirringthe mixture was stirred at 40° C. for 1 hour
9. extractionthe mixture was extracted with ethyl acetate
10. washwashed with 5% aqueous sodium chloride solution
11. customdried on magnesium sulfate
12. customThe solvent was evaporated
13. customthe residue was recrystallized from n-hexane

ORD record

ord-f5adb8dd11f34fcab8973acdda8e5840

Source dataset

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07816387B2