반응 #62681

반응 방정식

(R)-1-(2-methoxyethoxy)methyl-2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-carboxy-1,4-dihydropyridine

HCl

formula 18

(R)-1-(2-methoxyethoxy)methyl-2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-carboxy-1,4-dihydropyridine

acetone

→

(R)-2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-carboxy-1,4-dihydropyridine

용매

CH2Cl2

water

THF

water

반응 조건

후처리

1. 1
   여과the resulting precipitate is filtered

실험 절차

The resolved mono-ester of formula 18 is then deprotected by acid hydrolysis using a dilute (about 1N to about 2N) mineral acid in a suitable water-miscible solvent (preferably acetone or THF) at a temperature between about 0° and about 15° C. for about 30 to about 120 minutes. For example, (R)-1-(2-methoxyethoxy)methyl-2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-carboxy-1,4-dihydropyridine is dissolved in CH2Cl2, treated with 1N HCl at 0° C., and allowed to stand for one hour at room temperature. Then, water (100 mL) is added, and the resulting precipitate is filtered to yield (R)-2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-carboxy-1,4-dihydropyridine (19). (Scheme VI, Step 5)

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