反应详情

To a suspended solution of diethyl 2-methyl-4-(3-nitrophenyl)-6-formyl-1,4-dihydropyridine-3,5-dicarboxylate (233 mg) in ethanol (10 ml) was added sodium borohydride (22.7 mg) at 0° to 5° C under stirring and this mixture was further stirred at about 5° C. for an hour and 10 minutes. After the reaction, the mixture was adjusted to pH 4 to 5 with 0.1N-hydrochloric acid, and then the solvent was removed under reduced pressure. The residue was extracted with ethyl acetate and the extract was washed with water and dried over magnesium sulfate. The extract was concentrated under reduced pressure and the residue was crystallized by treating with a mixture of diethyl ether and n-hexane. The precipitated crystals were collected by filtration, dried and recrystallized from a mixture of diethyl ether and n-hexane to give crystals of diethyl 2-methyl-4-(3-nitrophenyl)-6-hydroxymethyl-1,4-dihydropyridine-3,5-dicarboxylate (152 mg), m.p. 141° to 142.5° C.

1. stirringthis mixture was further stirred at about 5° C. for an hour and 10 minutes
2. customAfter the reaction
3. customthe solvent was removed under reduced pressure
4. extractionThe residue was extracted with ethyl acetate
5. washthe extract was washed with water
6. dry with materialdried over magnesium sulfate
7. concentrationThe extract was concentrated under reduced pressure
8. customthe residue was crystallized
9. additionby treating with a mixture of diethyl ether and n-hexane
10. filtrationThe precipitated crystals were collected by filtration
11. customdried
12. customrecrystallized from a mixture of diethyl ether and n-hexane