反应详情

To a solution of diethyl 2-methyl-4-(2-nitrophenyl)-6-hydroxymethyl-1,4-dihydropyridine-3,5-dicarboxylate (1.95 g) in pyridine (25 ml) was dropwise added over 5 minutes a solution of p-chlorophenoxyacetyl chloride (3.07 g) in methylene chloride under stirring and ice-cooling. The resultant mixture was stirred at room temperature overnight under cooling with water at 20° C. After removal of the pyridine, water was added to the residue. The precipitated oily substance was extracted with ethyl acetate. The extract was adjusted to pH 4 to 5 with dil. hydrochloric acid, washed each three times with water and then an aqueous solution of sodium bicarbonate and dried over magnesium sulfate. The solvent was distilled off and the residual oil (4.75 g) was subjected to column chromatography on silica-gel using an eluent (benzene-ethyl acetate = 10:1 ) to give an oil (2.65 g) of diethyl 2-methyl-4-(2-nitrophenyl)-6-(4-chlorophenoxy)acetoxymethyl-1,4-dihydropyridine-3,5-dicarboxylate, m.p. 86° to 88° C. (recrystallized from a mixture of diisopropylether and ethanol).

1. temperatureice-cooling
2. customAfter removal of the pyridine, water
3. additionwas added to the residue
4. extractionThe precipitated oily substance was extracted with ethyl acetate
5. washwashed each three times with water
6. dry with materialan aqueous solution of sodium bicarbonate and dried over magnesium sulfate
7. distillationThe solvent was distilled off