反应详情

To a cold solution of dimethyl 2-methyl-4-(2-cyanophenyl)-6-formyl-1,4-dihydropyridine-3,5-dicarboxylate (2.3 g) in methanol (46 ml) at -5° C. was added portionwise sodium borohydride (140.7 mg) for 10 minutes, during which the temperature was kept at -4° to -5° C. with stirring. The mixture was stirred for additional 15 minutes at -6° C. The reaction mixture was diluted with water (20 ml) and acidified to about pH 5 with 50% actic acid, and then condensed under reduced pressure to separate out crystalline product. After adding water (30 ml), the crystals were collected by filtration, washed thoroughly with water and dried. Thus obtained crystals (2.05 g) were recrystallized from methanol (15 ml) to give pure crystals of dimethyl 2-methyl-4-(2-cyanophenyl)-6-hydroxymethyl-1,4dihydropyridine-3,5-dicarboxylate (1.67 g), mp 177° to 178° C.

1. customwas kept at -4° to -5° C.
2. stirringThe mixture was stirred for additional 15 minutes at -6° C
3. customcondensed under reduced pressure
4. customto separate out crystalline product
5. additionAfter adding water (30 ml)
6. filtrationthe crystals were collected by filtration
7. washwashed thoroughly with water
8. customdried
9. customThus obtained crystals (2.05 g) were recrystallized from methanol (15 ml)