Acetic Anhydride → 3-Ethyl 5-methyl 4-[3-(acetylamino)phenyl]-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate

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Reaction Steps

Under inert gas atmosphere Ac2O (43 mcl) is added to a stirred solution of (-)-2,6-dimethyl-3-carboethoxy-5-carbomethoxy-4-(3-aminophenyl)-1,4-dihydropyridine (100 mg) in pyridine (ml 1). 90 minutes after dilution with water (ml 50), extraction with AcOEt (3×10 ml) and crystallization from Et2O 70/EtOH 10, give mg 85 of +)-2,6-dimethyl-3-carboethoxy-5-carbomethoxy-4-(3-acetylaminophenyl)-1,4-dihydropyridine m.p. 197°-199° C. [α]D =+0.87°, [α]578 =+2.00°, [α]546 =+1.64° c=2.2 DMF.

Provenance & Evidence