Ammonium Chloride → 2,3-Diamino-4-(2-thienyl)pyridine

Temperature

0 °C

To a mixture of Compound 2 (2.06 g, 9.3 mmol) and 466 mg palladium carbon (10% by weight) in ethanol (130 ml) and ethyl acetate (65 ml), 28 ml of 1 M aqueous sodium borohydride was added at 0° C. The resulting mixture was stirred at 0° C. for 1 hour. To the mixture, 43 ml of 5% aqueous ammonium chloride was added. The mixture was filtered through celite. The filtrate was diluted with 500 ml water. After evaporation of ethanol and ethyl acetate, the mixture was extracted with ethyl acetate (250 ml×3). After drying over Na2SO4, the solvent was distilled off. The residue was purified by flash silica gel chromatography using methylene chloride:ethyl acetate (19:1 to 93:7) as an elution solvent to give 1.46 g of Compound 3 (Rf 0.24 on methylene chloride:ethyl acetate=9:1) in a yield of 82%.

1. additionwas added at 0° C
2. filtrationThe mixture was filtered through celite
3. additionThe filtrate was diluted with 500 ml water
4. customAfter evaporation of ethanol and ethyl acetate
5. extractionthe mixture was extracted with ethyl acetate (250 ml×3)
6. dry with materialAfter drying over Na2SO4
7. distillationthe solvent was distilled off
8. customThe residue was purified by flash silica gel chromatography

ORD record

ord-fc6e8ad14217459c916297dabbbe286f

Source dataset

uspto-grants-2011_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08030478B2