Methyl formate → 5-[(1-methyl-1H-pyrazol-4-yl)methyl]-2-thioxo-2,3-dihydro-4(1H)-pyrimidinone

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Reaction Steps

To a stirred ice-cooled solution of potassium tert-butoxide (8.41 g, 74.9 mmol) in dry THF (150 mL) under argon was added dropwise a solution of methyl 3-(1-methyl-1H-pyrazol-4-yl)propanoate (4.2 g, 24.97 mmol) and methyl formate (4.50 g, 74.9 mmol) in THF (150 mL). The mixture was then allowed to warm to room temperature and stirring continued overnight. After removing the solvent, thiourea (1.901 g, 24.97 mmol) and methanol (100 mL) was added. The mixture was heated at 50° C. overnight. After removing the solvent, water (10 mL) was added. and acidified to pH 3 with HCl. The mixture was stirred in ice bath for 1 h. Filtration then drying in vacuo at 50° C. overnight then afforded the title compound (2.8 g, 12.60 mmol, 50.4% yield). LCMS: rt=0.99 min, [M+H+]=223

Provenance & Evidence