Acetone → 7-bromo-2,2-dimethyl-6-(1H-pyrazol-4-yl)-2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-one

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Reaction Conditions

Reaction Steps

To a solution of 2,2-dimethyl-6-(1H-pyrazol-4-yl)-2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-one (248 mg, 1.00 mmol) in acetic acid (5 mL) was added slowly bromine (0.077 mL, 1.50 mmol) with vigorous stirring. After 3 min, the mixture was poured into saturated aqueous NaHCO3 and extracted with EtOAc, and the extract was dried over MgSO4, filtered and concentrated under reduced pressure to give a yellow solid. This residue was mixed with acetone (5.0 mL, 68.1 mmol), PTSA (9.5 mg, 0.050 mmol), MgSO4 (120 mg, 1.00 mmol) and DMF (1 mL). This mixture was stirred at 60° C. for 1 h. Then, the mixture was poured into saturated aqueous NaHCO3 and extracted with EtOAc, and the extract was dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, hexane to EtOAc) to give a pale yellow solid (100 mg). This solid was triturated with EtOAc and collected by filtration to afford the title compound (69.9 mg, 21%) as a pale yellow solid:

Provenance & Evidence