Imidazole → 6-(1H-imidazol-1-yl)-1,2,2-trimethyl-2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-one

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Reaction Conditions

Reaction Steps

A mixture of 6-bromo-1,2,2-trimethyl-2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-one (138 mg, 0.50 mmol), imidazole (68.1 mg, 1.00 mmol), copper (powder) (6.35 mg, 0.10 mmol) and water (2 mL) was refluxed for 1 h. The mixture was concentrated under reduced pressure. DMF (2 mL), cesium carbonate (326 mg, 1.00 mmol), imidazole (408 mg, 6.00 mmol) and copper(I) iodide (19.1 mg, 0.10 mmol) were added to the residue, and the mixture was purged with argon. Then, the mixture was stirred at 140° C. for 4 h. Then, the mixture was poured into saturated aqueous NaHCO3 (100 mL) and extracted with EtOAc/THF (2:1, 100 mL×2), and the extract was dried over MgSO4, filtered and concentrated under reduced pressure. The residual oil was purified by column chromatography (silica gel, EtOAc to 80:20 EtOAc/MeOH) to give a solid (56 mg). The solid was triturated with EtOAc/hexane, collected by filtration and washed with water to afford the title compound (10.4 mg, 7.9%) as a pale yellow solid:

Provenance & Evidence