Hydrochloric Acid → 5-Carboxy-2-methylthiomethyl-6-methyl-4-(3-nitrophenyl)-3-carboethoxy-1,4-dihydropyridine

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Reaction Steps

A suspension of 2-methylthiomethyl-6-methyl-4-(3-nitrophenyl)-3-carboethoxy-5-carboallyloxy-1,4-dihydropyridine (g 0.27), palladium on charcoal (10% 6 mg), ammonium formate (mg 71) and triphenylphosphine (mg 3) in anhydrous 1,4-dioxane, is heated at the reflux temperature for 8 hours. The reaction mixture is cooled at room temperature, poured into an aqueous solution of hydrochloric acid (pH=2) and extracted with ethyl acetate (2×20 ml). The combined organic extracts are washed with aqueous sodium carbonate (1N; 3×10 l), the basic washings are collected, acidified to pH 5-6 with diluted aqueous hydrochloric acid. The resulting suspension is extracted with ethyl acetate (2×25 ml) the combined organic extracts are dried on Na2SO4 and evaporated under reduced pressure to give mg 160 of 5-carboxy-2-methylthiomethyl-6-methyl-4-(3-nitrophenyl)-3-carboethoxy-1,4-dihydropyridine as an amorphous solid.

Provenance & Evidence