4-Quinolinecarboxylic acid → N-[[1-[(4-methoxyphenyl)methyl]cyclopentyl]carbonyl]-4-[(4-quinolinylcarbonyl)amino]-L-phenylalanine

Participants

Reaction Steps

A solution of 4-amino-N-[[1-[(4-methoxyphenyl)methyl]cyclopentyl]carbonyl]-L-phenylalanine methyl ester (30.7 mg, 0.075 mmol), quinoline-4-carboxylic acid (17 mg, 0.10 mmol), and HBTU (38 mg, 0.10 mmol) in 1 mL of DMF was treated with diisopropylethylamine (30 μL, 0.17 mmol). The mixture was stirred over night and was diluted with 15 mL of ethyl acetate and 10 mL of ether and was washed with water (2×10 mL), saturated NaHCO3 (1×10 mL) and was dried (MgSO4). Concentration gave 42 mg which was dissolved in 3 mL of methanol. Sodium hydroxide (0.10 mL, 4 N, 0.4 mmol) was added and the mixture was stirred for 2 hours. The excess base was quenched by addition of acetic acid (0.1 mL), the solution was filtered through a 0.2μ nylon filter and the filtrate was purified 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 30 min. The peak eluting at 74% acetonitrile was concentrated and lyophilized to give N-[[1-[(4-methoxyphenyl)methyl]cyclopentyl]carbonyl]-4-[(4-quinolinylcarbonyl)amino]-L-phenylalanine (22.8 mg), HR—FAB—MS: obs. mass 552.2482. Calcd. mass 552.2498 (M+H). The peak eluting at 82.6% acetonitrile was recovered N-[[1-[(4-methoxyphenyl)methyl]cyclopentyl]carbonyl]-4-[(4-quinolinylcarbonyl)amino]-L-phenylalanine methyl ester (11.2 mg), HR—FAB—MS: obs. mass 566.2675. Calcd. mass 566.2655 (M+H).

Provenance & Evidence