Diisopropylethylamine → HCID 69020035, compound

Participants

Reaction Steps

By using an analogous procedure described in General Procedure I Method A, N,β,β,3-tetramethyl-L-phenylalanyl-N1-[(1S,2E)-3-carboxy-1-isopropyl-2-butenyl]-N1,3-dimethyl-L-valinamide (100 mg, 0.205 mmol) is treated with hydroxybenzotriazole (36 mg, 0.27 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (59 mg, 0.31 mmol) in anhydrous acetonitrile (10 ml) at room temperature for 40 hours, followed by addition of diisopropylethylamine (0.143 ml, 0.82 mmol) and a solution of L-prolyl-N-benzyl-L-prolinamide trifluoroacetic acid salt (255 mg, 0.615 mmol) in anhydrous acetonitrile (3 ml). After stirring at room temperature for 4 hours, the product is purified by preparative HPLC, to provide the trifluoroacetic acid salt of the title compound (126.6 mg, 69%) as a white amorphous solid. MS (ES): m/z 771.5 (M+H). IR cm−1: 3306.94, 2969.17, 1673.9, 1642.27, 1203.38. Analytical HPLC: (4.6×150 mm YMC Pack Pro C18 column eluted with 10 to 100% acetonitrile in water containing 0.02% formic acid over 35 minutes): 92.56% (at 17.7 minutes) of 1-{(2E,4S)-2,5-dimethyl-4-[methyl(N,β,β,3-tetramethyl-L-phenylalanyl-3-methyl-L-valyl)amino]hex-2-enoyl}-D-prolyl-N-benzyl-D-prolinamide, and 6.92% (at 18.5 minutes) of the other diastereomer.

Provenance & Evidence