Tetrabutylammonium Fluoride → 2,2-dimethyl-6-(5-{[(2-phenylethyl)amino]methyl}-1H-pyrazol-4-yl)-2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-(2,2-dimethyl-4-oxo-1,2,3,4-tetrahydrothieno[3,2-d]pyrimidin-6-yl)-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrazole-5-carbaldehyde (122 mg, 0.30 mmol), 2-phenylethanamine (0.151 mL, 1.20 mmol) and THF (5 mL) was stirred at room temperature overnight. Then, sodium borohydride (0.023 g, 0.60 mmol) and MeOH (2 mL) were added. After 30 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. The residue was purified by column chromatography (Purif, NH, 95:5 hexane/EtOAc to EtOAc then to 80:20 EtOAc/MeOH) to afford 2,2-dimethyl-6-(5-{[(2-phenylethyl)amino]methyl}-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrazol-4-yl)-2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-one (140 mg). 2,2-Dimethyl -6-(5-{[(2-phenylethyl)amino]methyl}-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-pyrazol-4-yl)-2,3-dihydrothieno[3,2-d]pyrimidin-4(1H)-one (140 mg) was dissolved with N,N,N,N-tetrabutylammonium fluoride (1.0 M in THF, 3.0 mL, 3.00 mmol) and the mixture was stirred at 60° C. overnight. The mixture was filtered, and the filtrate 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 (Purif, NH, 95:5 hexane/EtOAc to EtOAc then to 80:20 EtOAc/MeOH) to afford the title compound (27.5 mg, 24%) as a colorless oil:

Provenance & Evidence