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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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%.

Herkunft & Nachweise