Hydrochloric Acid → Z-Tyr-Gly-Gly-Phe-OCH2CN

Participants

Reaction Steps

300 mg (0.69 mmole) of Z-Tyr-Gly-Gly-OH was dissolved in 5 mL dry THR, and the temperature was lowered to -10° C. in a dry ice/ethylene glycol bath. One equivalent of N-methyl morpholine and 1 equivalent of isobutyl chloroformate was added with stirring. One equivalent of H-L-Phe-OCH2CN, HCl (166 mg), and 1 equivalent of N-methyl morpholine dissolved in 2 mL DMF was added and the solution stirred for 5 minutes. The reaction was allowed to come to room temperature, then diluted with six volumes of ethyl acetate. The ethyl acetate was washed with cold water (2x), 0.1 N HCl (3x), 0.2 M Na2CO3 (2x), water (2x) and concentrated brine (1x). The ethyl acetate as concentrated carefully under vacuum, and the residue was recrystallized from CH2Cl2 /hexanes to give 260 mg (62%) of Z-Tyr-Gly-Gly-Phe-OCH2CN. Amino acid analysis: tyr1.0, gly1.9, phe0.9.

Provenance & Evidence