反应详情

A mixture containing 69 g of dimethyl 4-(2-fluorophenyl)-2,6-dimethyl-3,5-pyridinedicarboxylate, 300 ml of methanol and 100 ml of 35% aqueous sodium hydroxide solution was refluxed with stirring for 5 hours and then allowed to stand at room temperature overnight. The methanol was removed using a rotary evaporator and to the residual liquid was added 200 ml of water and filtered. The filtrate was acidifed with concentrated hydrochloric acid whereupon there precipitated a cream colored solid, which was washed with water and dried at 80°-85° C. to yield 52.6 g (88%) of 4-(2-fluorophenyl)-2,6-dimethyl-3,5-pyridinedicarboxylic acid, m.p. >285° C.

1. temperaturewas refluxed
2. waitto stand at room temperature overnight
3. customThe methanol was removed
4. customa rotary evaporator
5. additionto the residual liquid was added 200 ml of water
6. filtrationfiltered
7. customprecipitated a cream colored solid, which
8. washwas washed with water
9. customdried at 80°-85° C.