Citric Acid → Z-Leu-Gly-OEt

Participants

Reaction Conditions

Reaction Steps

1.86 Milliliters of N-methylmorpholine was dissolved in 60 ml of tetrahydrofuran and to this solution 4.85 g of Z-Leu-OH was added. The mixture was cooled to -15° C. and 2.41 ml of isobutyl chloroformate was added and then vigorously stirred for 30 seconds. To this reaction mixture, 40 ml of a dimethylformamide solution containing 2.54 g of H-Gly-OC2H5, and 2.56 ml of triethylamine were added and stirred for 1 minute. After the reaction mixture was warmed at 0° C. for 5 minutes, then at 40° C. for 2 minutes and was stirred at a room temperature for 15 minutes. Tetrahydrofuran and dimethylformamide were removed by distillation to obtain the residue, then 1M-citric acid was added to this residue and the crystals thus formed were collected by filtration. The crystals were washed with water until the filtrate become neutral, and the crystals were dried, reprecipitated from ethyl acetate-ether to obtain 4.68 g of Z-Leu-Gly-OC2H5.

Provenance & Evidence