Bromine → 7-bromo-2,2-dimethyl-6-(5-methyl-1H-pyrazol-4-yl)-2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-one

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Reaction Conditions

Reaction Steps

To a vigorously stirred solution of 2,2-dimethyl-6-(5-methyl-1H-pyrazol-4-yl)-2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-one (0.080 g, 0.305 mmol) in acetic acid (2 mL) was added slowly bromine (0.019 mL, 0.366 mmol). After 5 min, the mixture was poured into excess saturated aqueous NaHCO3 and extracted with EtOAc, and the extract was dried over MgSO4, filtered and concentrated under reduced pressure. The residue was mixed with acetone (5 mL), PTSA (3 mg) and DMF (1 mL). The mixture was stirred for 30 min at 70° C. and 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 (Purif, silica gel, 95:5 hexane/EtOAc to EtOAc) to give a yellow solid. This solid was triturated with EtOAc/hexane, and the precipitate was collected by filtration to afford the title compound (65.4 mg, 63%) as a yellow solid:

Provenance & Evidence