Condensation of Ethyl 1-Benzyl-3-oxo-4-isopropyl-2-pyrrolidine-carboxylate with Ethyl Cyanoacetate

Abstract

Catalytic reduction of a combination of ethyl 1-benzyl-3-oxo-4-isopropyl-2-pyrrolidine-carboxylate and ethyl cyanoacetate over palladium-carbon afforded a substance assumed to be ethyl α-hydroxymethyl-2-ethoxycarbonyl-4-isopropyl-3-pyrrolidineacetate, whose reduction in glacial acetic acid over platinum oxide gave ethyl α-hydroxy-2-ethoxycar-bonyl-4-isopropyl-3-pyrrolidineacetate. Hydrolysis of the latter furnished a dibasic amino acid, α-hydroxymethyl-2-carboxy-4-isopropyl-3-pyrrolidineacetic acid.
These facts showed that reduction over palladium-carbon in hydrochloric acid effects reduction of a nitrile to hydroxymethylene group. In order to provide explanation on this observation, catalytic reduction of two kinds of chemically different nitriles was carried out under the same conditions as above. Reduction of ethyl 2-(N-benzyl-N-cyanomethylaminomethyl) isovalerate afforded an amino alcohol compound, and that of ethyl 2-(cyanomethylaminomethyl) isovalerate gave the corresponding secondary amine.