Ethyl orthoformate → 3-(3-Methoxypropyl)-2-thioxanthine

Participants

Reaction Steps

Platinum on carbon (0.5 g) was added to a solution of the crude 6-amino-1-(3-methoxypropyl)-5-nitroso 2-thioxo-2,3-dihydro-1H-pyrimidin-4-one (1.80 g, 7.38 mmol) in tetrahydrofuran (80 mL) and water (20 mL) and the reaction mixture was hydrogenated at atmospheric pressure for 2 h. The catalyst was filtered off and the pale brown filtrate was co-evaporated with ethanol (250 mL). The resulting brown solid, 1.6 g, was used in the next step without further purification. 5,6-Diamino-1-cyclohexylmethyl-2-thioxo-2,3-dihydro-1H-pyrimidin-4-one (1.6 g, 12.2 mmol) was dissolved in ethanol (10 mL) and triethyl orthoformate (10 mL) and the reaction mixture was refluxed for 2.5 h. The solvents were evaporated off and the resulting brown solid was purified by flash chromatography (heptane/ethyl acetate, 4:1-1:1) to give the title compound (110 mg, 9%).

Provenance & Evidence