Hydrochloric Acid → epsilon-benzyloxycarbonyl-L-lysyl-sarcosyl-L-proline methyl ester hydrochloride

Participants

Reaction Steps

The reaction mixture consequently formed was filtered. The filtrate was concentrated under a vacuum. The residue of the concentration was dissolved in 50 ml of ethyl acetate and the resultant solution was filtered. The filtrate was washed with an aqueous 10% citric acid solution, an aqueous 5% sodium hydrogen carbonate solution, and water sequentially in the order mentioned and dried with anhydrous sodium sulfate. The dried substance was distilled under a vacuum to expel the solvent. The residue was solidified with n-hexane to afford 5.05 g of α-tertiary butyloxycarbonyl-ε-benzyloxycarbonyl-L-lysyl-sarcosyl-L-proline methyl ester (melting point 45° to 48° C., yield 79%). This ester was dissolved in 80 ml of a solution prepared by dissolving dry hydrogen chloride gas in ethyl acetate and adjusting the concentration to 3.5N and then left standing for reaction at room temperature for one hour.

Provenance & Evidence