Diisopropylethylamine → 4-(2,3-dihydro-1,3-dioxo-1H-pyrrolo[3,4-c]pyridin-2-yl)-N-[[1-[(4-methoxyphenyl)methyl]cyclopentyl]carbonyl]-L-phenylalanine

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Reaction Steps

A solution of 4-amino-N-[[1-[(4-methoxyphenyl)methyl]cyclopentyl]carbonyl]-L-phenylalanine (98 mg, 0.23 mmol), DIPEA (30 μL, 0.23 mmol) and 3,4-pyridinedicarboxylic acid anhydride (114 mg, 0.77 mmol) in dichloromethane (10 mL) was stirred 18 hr at room temperature. The mixture was concentrated to remove most of the dichloromethane and the residue was taken up in DMF (3 mL). Carbonyl diimidazole (103 mg, 0.64 mmol) was added to the resulting solution and the reaction was allowed to proceed for 18 hr. The resulting mixture was purified directly by RP-HPLC on a 4×30 cm Rainin C-18 column using a gradient of 5 to 95% acetonitrile:water containing 0.75% trifluoroacetic acid at a flow of 49 mL/min over 35 min. The peak eluting at 45.6% acetonitrile was concentrated and lyophilized to give 4-(2,3-dihydro-1,3-dioxo-1H-pyrrolo[3,4-c]pyridin-2-yl)-N-[[1-[(4-methoxyphenyl)methyl]cyclopentyl]carbonyl]-L-phenylalanine (28 mg) HR FABMS: obs. mass 528.2146. Calcd. mass 528.2134 (M+H).

Provenance & Evidence