Thionyl Chloride → 4-Chloro-5-ethyl-6-methylthieno[2,3-d]pyrimidine

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Reaction Steps

A mixture of 5-ethyl-6-methyl-3-hydrothiopheno[2,3-d]pyrimidin-4-one (0.5 g), thionyl chloride (5 mL) and catalytic amount of DMF (0.2 mL) was refluxed for 1 h. Solvents were removed under vacuum and the mixture was diluted with ice cold water and stirred for 10 min. The solution was extracted with chloroform (3×100 mL) and the combined chloroform layer was washed with water, brine and dried over sodium sulfate. The solution was filtered and evaporated the solvent. The residue was triturated with hexane to give the product as a dark brown color solid (400 mg, 73%), mp 52-56° C. 1H NMR (400 MHz, CDCl3): δ 8.73 (1H, s), 3.05 (2H, q, J=7.5 Hz), 2.55 (3H, s), 1.24 (3H, t, J=7.6 Hz).

Provenance & Evidence