反应详情

15.5 g of methyl 2-methoxy-6-methylpyrimidine-4-carboxylate are added to a stirred solution of 3.6 g of sodium hydroxide in 100 ml of methanol and 10 ml of water. Stirring is continued at room temperature until the starting material disappears (TLC checking; 3 h). The methanol is distilled off under reduced pressure, the residue is taken up in water and the mixture is extracted once with ethyl acetate. The aqueous phase is acidified to pH 2 with conc. hydrochloric acid and then stirred for 1 h, and the product is filtered off with suction. 6.6 g of 2-methoxy-6-methylpyrimidine-4-carboxylic acid of melting point 161°-163° C. are obtained in this way. Concentration and extraction of the mother liquor using dichloromethane additionally gives 3.1 g of product of melting point 159°-161° C.

1. customis continued at room temperature until the starting material
2. custom(TLC checking; 3 h)
3. distillationThe methanol is distilled off under reduced pressure
4. extractionthe mixture is extracted once with ethyl acetate
5. stirringstirred for 1 h
6. filtrationthe product is filtered off with suction