1,1'-Carbonyldiimidazole → Methyl 4-[6-(2-cyclopentylacetamido)indol-1-ylmethyl]-3-methoxybenzoate

Participants

Reaction Steps

A solution of cyclopentylacetic acid (0.24 ml) and 1,1'-carbonyldiimidazole (0.34 g) in methylene chloride (3 ml) was heated under reflux for 30 minutes and then treated with a solution of ester (B) (0.5 g) in methylene chloride (3 ml). The mixture was heated under reflux for 30 minutes, stirred at room temperature for 24 hours, and then diluted with ethyl acetate. This organic solution was washed sequentially with 10% v/v hydrochloric acid, water, and brine, dried (MgSO4) and evaporated. The residue was purified by flash chromatography on a 6×18 cm silica gel column using 99:1 v/v ethyl acetate:toluene as the eluent followed by recrystallization from hexane/ethyl acetate to give methyl 4-[6-(2-cyclopentylacetamido)indol-1-ylmethyl]-3-methoxybenzoate (P) as a solid; partial NMR: 2.0-2.5(br m, 3H, CH2CH), 3.9(s, 3H, OCH3), 4.0(s, 3H, OCH3), 5.3(s, 2H, NCH2).

Provenance & Evidence