反应详情

A solution of 2-chloro-5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-4-fluorophenyl isothiocyanate (6.0 g, 15.8 mmol) and β-alanine, methyl ester, hydrochloride salt (2.65 g, 19.0 mmol) in acetone is cooled to 0° C., treated dropwise with a solution of triethylamine (1.92 g, 19.0 mmol) in methylene chloride, stirred overnight at room temperature, and poured into water. The resultant aqueous mixture is extracted with ethyl acetate. The organic extracts are combined, washed sequentially with 5% hydrochloric acid and brine, dried over anhydrous magnesium sulfate, and concentrated in vacuo to obtain a brown foam. Flash column chromatography of the foam using silica gel and a (9:1) methylene chloride/diethyl ether solution gives the title product as an off-white foam (5.68 g, 74.4% yield, mp 110° C.) which is identified by 1H NMR spectral analysis.

1. extractionThe resultant aqueous mixture is extracted with ethyl acetate
2. washwashed sequentially with 5% hydrochloric acid and brine
3. dry with materialdried over anhydrous magnesium sulfate
4. concentrationconcentrated in vacuo
5. customto obtain a brown foam