ethyl 4-fluoro-3-oxopentanoate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of ethyl 4-fluoro-3-oxopentanoate (5.0 g), butanimidamide hydrochloride (4.6 g) and sodium methoxide (28% methanol solution, 16 mL) in methanol (50 mL) was stirred overnight. The reaction mixture was diluted with ethyl acetate, washed with 1 M hydrochloric acid, dried over sodium sulfate and concentrated. The residue was purified by silica gel column chromatography to give the title compound as a pale yellow oil (5.7 g, 100%). washed with 1 M hydrochloric acid dried over sodium sulfate concentrated The residue was purified by silica gel column chromatography

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of ethyl 4-fluoro-3-oxopentanoate (5.0 g), butanimidamide hydrochloride (4.6 g) and sodium methoxide (28% methanol solution, 16 mL) in methanol (50 mL) was stirred overnight. The reaction mixture was diluted with ethyl acetate, washed with 1 M hydrochloric acid, dried over sodium sulfate and concentrated. The residue was purified by silica gel column chromatography to give the title compound as a pale yellow oil (5.7 g, 100%). washed with 1 M hydrochloric acid dried over sodium sulfate concentrated The residue was purified by silica gel column chromatography

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution in which 24.3 g of ethyl 4-fluoro-3-oxopentanoate had been dissolved in 330 ml of methanol were added 72.3 g of a 28 % sodium methoxide methanol solution and 15.6 g of formarnidine acetate, and the mixture was stirred at 50° C. for 3 hours. To the mixture was further added 7.81 g of formamidine acetate and after stirring the mixture at 50° C. for 4 hours, the mixture was cooled to 10° C. or lower. After cooling, 18.8 g of conc. sulfuric acid and 13.5 g of water were added to the reaction mixture. After stirring the mixture at 50° C. for 15 minutes, insolubles were removed by filtration and the filtrate was quantitated by the liquid chromatography internal standard method. As a result, 18.0 g of 6-(1-fluoroethyl)-4-pyrimidone was formed (yield: 84.6%). after stirring the mixture at 50° C. for 4 hours the mixture was cooled to 10° C. After cooling After stirring the mixture at 50° C. for 15 minutes insolubles were removed by filtration