1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → dibenzylphosphoryl-L-alanyl-L-prolyl-L-phenylalanine ethylester

Participants

Reaction Conditions

Reaction Steps

Dibenzylphosphoryl-L-alanyl-L-proline (1.2 g, 2.5 m mole), HOBt (338 mg, 2.5 m mole) and L-phenylalanine ethylester hydrochloride (690 mg, 3 m mole) were suspended in DMF (10 ml) and WSC (0.5 ml) were added thereto while cooling to -15° C. and stirring. The reaction was carried out for 3 hours under cooling and then overnight at room temperature. To the reaction solution, ethyl acetate (100 ml) was added, and the mixture was washed with 1N hydrochloric acid and water in order, and dried with anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain oily dibenzylphosphoryl-L-alanyl-L-prolyl-L-phenylalanine ethylester (1.3 g). The oily material gave a single spot with Rf 0.7 by thin layer chromatography (developing solvent; chloroform:methanol:acetic acid=95:5:3, colour forming method: spraying of 25% hydrobromic acid and 0.1% ninhydrine, and heating).

Provenance & Evidence