Sodium Hydroxide → 2-Methyl-4-oxo-6-(pyridin-4-yl)-1,2,3,4-tetrahydrothieno[3,2-d]pyrimidine-2-carboxylic acid

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Reaction Steps

A mixture of methyl 2-methyl-4-oxo-6-(pyridin-4-yl)-1,2,3,4-tetrahydrothieno[3,2-d]pyrimidine-2-carboxylate (0.152 g, 0.500 mmol) and 2 M sodium hydroxide (0.75 mL, 1.5 mmol) in methanol (10 mL) was stirred at room temperature for 3 h, and the resulting suspension was stored at −20° C. for 65 h. Then, the reaction mixture was warmed to room temperature, and the precipitate was collected by filtration and washed with methanol (1 mL) to give a yellow solid. This yellow solid was partitioned between ethyl acetate (25 mL) and water (10 mL), and the ethyl acetate layer was extracted with water (2×5 mL). The combined aqueous layers were acidified with acetic acid to a pH of 5 to 6, and the resulting orange precipitate was collected by filtration and washed with water to give an orange solid. Trituration with acetonitrile/methanol gave the title compound (0.031 g, 21%) as an orange solid:

Provenance & Evidence