反应详情

To a suspension of 2-ethoxyethyl 2-methyl-4-(3-nitrophenyl)-5-ethoxycarbonyl-6-formyl-1,4-dihydropyridine-3-carboxylate (1.13 g) in ethanol (15 ml) was added sodium borohydride (80 mg) with stirring under ice-cooling, and this mixture was further stirred for an hour at the same temperature. The reaction mixture was adjusted with dilute hydrochloric acid to pH 6 under ice-cooling and then the solvent was distilled off. To the residue was added water and the aqueous mixture was extracted with diethyl ether. The extract was washed with water and dried over magnesium sulfate. Removal of the solvent gave an oil, which was crystallized by treating with n-hexane. These were recrystallized from a mixture of diethyl ether and n-hexane to give pure crystals (900 mg) of 2-ethoxyethyl 2-methyl-4-(3-nitrophenyl)-5-ethoxycarbonyl-6-hydroxymethyl-1,4-dihydropyridine-3-carboxylate, m.p. 99° to 100° C.

1. temperaturecooling
2. stirringthis mixture was further stirred for an hour at the same temperature
3. temperaturecooling
4. distillationthe solvent was distilled off
5. additionTo the residue was added water
6. extractionthe aqueous mixture was extracted with diethyl ether
7. washThe extract was washed with water
8. dry with materialdried over magnesium sulfate
9. customRemoval of the solvent
10. customgave an oil, which
11. customwas crystallized
12. additionby treating with n-hexane
13. customThese were recrystallized from a mixture of diethyl ether and n-hexane