Diisopropylcarbodiimide → Boc-Phe-N-Me-Val-Tyr(3-tBu) NH3

Participants

Reaction Steps

A mixture of 810 mg of Z-N-Me-Val-Tyr(3-tBu)-NH2 and 300 mg of 10% palladium carbon in 50 ml of methanol was stirred under a hydrogen stream for 13 hours and a half. The reaction mixture was filtered and the filtrate was distilled off under reduced pressure. To a solution in DMF (12 ml) of 470 mg (1.35 mmol) of the resulting N-Me-Val-Tyr(3-tBu)-NH2, 390 mg (1.48 mmol) of Boc-Phe-OH and 230 mg (1.48 mmol) of HOBT, 0.23 ml (1.48 mmol) of DIC was added dropwise under cooling with ice and the mixture was stirred at room temperature for 13 hours and a half. The reaction mixture was diluted with ethyl acetate and washed with saturated brine. The organic layer was dried with anhydrous sodium sulfate and concentrated under reduced pressure; the resulting residue was subjected to silica gel column chromatography (eluting solvent consisting of methylene chloride, methanol and aqueous ammonia at a ratio of 100:3:1) to give Boc-Phe-N-Me-Val-Tyr(3-tBu)-NH3 in the amount of 380 mg (47%).

Provenance & Evidence