Citric Acid → HCID 7154480, compound

Participants

Reaction Steps

The thus obtained N-t-butoxycarbonyl-prolylleucyl-glycine methyl ester in an amount of 294.6 g was dissolved in 1.6 l of methanol. To this, 1.6 l of 1N-NaOH was added dropwise with ice cooling and the reaction was carried out at room temperature for 2 hours. Subsequently, 20% citric acid was added dropwise to the reaction mixture to make the pH 3 to 4. Then, the whole reaction mixture was extracted with 5 l of ethyl acetate, and the extract was washed well with 5% citric acid solution and saturated sodium chloride aqueous solution, and dried. After removing the solvent by distillation, a white solid was obtained. The resulting solid of N-t-butoxycarbonyl-prolyl-leucyl-glycine was purified by washing with petroleum ether. Yield: 269.3 g (94.7%). Melting point 87°-90° C. [α]D20 =-80.5° (C=1, ethanol). Rf =0.46 (TLC, chloroform: methanol: acetic acid =95:5:3 by volume).

Provenance & Evidence