Acetone → 6-(5-ethyl-1H-pyrazol-4-yl)-1,2,2-trimethyl-2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-one

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Reaction Steps

A mixture of 5-ethyl-N,N-dimethyl-4-(1,2,2-trimethyl-4-oxo-1,2,3,4-tetrahydrothieno[3,2-d]pyrimidin-6-yl)-1H-pyrazole-1-sulfonamide (129 mg, 0.325 mmol) and TFA (2.00 mL, 26.0 mmol) was stirred for 1 h at room temperature. 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 mixed with acetone (5 mL, 68.1 mmol), MgSO4 (78 mg, 0.649 mmol), PTSA (6.2 mg, 0.032 mmol) and DMF (1 mL). This mixture was stirred at 60° C. for 1 h. The mixture was poured into saturated aqueous NaHCO3 and extracted with 3:1 EtOAc/THF, and the extract was dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified by column chromatography (Purif, silica gel, hexane to EtOAc then to 80:20 EtOAc/MeOH). The obtained solid was triturated with EtOAc and collected by filtration to afford the title compound (41.2 mg, 44%) as a pale yellow solid:

Provenance & Evidence