反应详情

A solution of 1,4-dihydro-2-methoxy-6-methyl-4-(3-nitrophenyl)-5-pyrimidinecarboxylic acid, ethyl ester (750 mg., 2.35 mmole) and dry pyridine (0.57 ml., 7.05 mmole) in dichloromethane (5.0 ml.) at -20° (methanol/ice bath) under argon is treated dropwise via gas-tight syringe with propionyl chloride (0.26 ml., 2.82 mmole). The reaction mixture is stirred for 2.0 hours and evaporated. The solid yellow residue is dissolved in methanol (25 ml.) and tetrahydrofuran (15 ml.) and treated with 5N hydrochloric acid (6.0 ml.). After stirring at room temperature for 1.0 hour, the reaction mixture is evaporated. The residue is partitioned between ethyl acetate and sodium bicarbonate solution. The organic phase is washed with saturated sodium chloride, dried over magnesium sulfate, and evaporated. The residue is flash chromatographed to give the title compound as a white foam (567 mg.). This foam is combined with material from another batch (290 mg.) and recrystallized from dichloromethane/isopropyl ether to give large shiny white crystals (784 mg., m. p. 152°-154°). TLC(silica gel; 50% ethyl acetate:hexanes) Rf =0.57.

1. customevaporated
2. dissolutionThe solid yellow residue is dissolved in methanol (25 ml.)
3. additiontetrahydrofuran (15 ml.) and treated with 5N hydrochloric acid (6.0 ml.)
4. stirringAfter stirring at room temperature for 1.0 hour
5. customthe reaction mixture is evaporated
6. customThe residue is partitioned between ethyl acetate and sodium bicarbonate solution
7. washThe organic phase is washed with saturated sodium chloride
8. dry with materialdried over magnesium sulfate
9. customevaporated
10. customchromatographed