Hydrochloric Acid → N-(2-Nitrobenzene-1-sulfonyl)-beta-alanine

To a solution of methyl 3-(2-nitrobenzenesulfonylamino)propionate (6.15 g) in ethanol (20 mL)-methanol (5 mL) was added 5 mol/L aqueous sodium hydroxide solution (20 mL), and the mixture was stirred at room temperature overnight. The reaction mixture was acidified by addition of 2 mol/L hydrochloric acid (55 mL), and the resulting mixture was extracted with ethylacetate. The extract was washed with water and brine, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure, and the residue was treated with n-hexane and ethylacetate. The precipitated crystals were collected by filtration, washed with n-hexane and dried under reduced pressure to give 3-(2-nitrobenzenesulfonylamino)propionic acid (5.83 g). To a solution of the obtained 3-(2-nitrobenzenesulfonylamino)propionic acid (0.5 g) in tetrahydrofuran (5 mL) was added 1,1′-carbonylbis-1H-imidazole (0.35 g), and the mixture was stirred at room temperature for 2 hours. To the reaction mixture was added 1-methylpiperazine (0.46 g), and the mixture was stirred at 50° C. for 3 days. The reaction mixture was concentrated under reduced pressure, and the residue was purified by column chromatography on aminopropylated silica gel (eluent: dichloromethane/methanol 40/1) to give the title compound (0.61 g).

1. extractionthe resulting mixture was extracted with ethylacetate
2. washThe extract was washed with water and brine
3. dry with materialdried over anhydrous sodium sulfate
4. customThe solvent was removed under reduced pressure
5. additionthe residue was treated with n-hexane and ethylacetate
6. filtrationThe precipitated crystals were collected by filtration
7. washwashed with n-hexane
8. customdried under reduced pressure

ORD record

ord-ebb0dd041259477f9e2b2e0069cbeaca

Source dataset

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08324176B2