HCID 86755835, compound → HCID 131716382, compound

Participants

Reaction Steps

The N2 -(1-carboxy-3-oxo-3-phenylpropyl)-L-lysine derivative can be subjected to catalytic hydrogenolysis proceeding gently in water, an alcohol or a polar protic solvent such as acetic acid in the presence of a suitable amount of an acid such as sulfuric acid, hydrochloric acid or formic acid to give the N2 -(1-carboxy-3-phenylpropyl)-L-lysine derivative in a high yield. In catalytic hydrogenolysis, palladium, Raney nickel, and the like are examples of suitable catalysts. For instance, when N2 -[1-ethoxycarbonyl-3-oxo-3-phenylpropyl]-N6 -trifluoroacetyl-L-lysine is subjected to catalytic hydrogenolysis, the lysine derivative is hydrogenated in an alcohol (such as ethanol) as the solvent in the presence of the acid at a temperature of 0° C. to 60° C., preferably from 5° C. to 40° C. for several to 24 hours by using palladium/carbon as the catalyst to give almost quantitatively N2 -(1-ethoxycarbonyl-3-phenylpropyl)-N6 -trifluoroacetyl-L-lysine. After completing the hydrogenation, the catalyst is removed from the reaction mixture, the acid of the resulting solution is neutralized with an alkali, from which the solvent is distilled away, and then the desired compound having the (S,S)-configuration can be isolated in a usual manner such as extraction. If necessary, recrystallization can be conducted from the obtained reaction mixture.

Provenance & Evidence