Hydrochloric Acid → Methyl 4-[5-(2-cyclopentylacetamido)-1-ethylindol-3-ylmethyl]-3-methoxybenzoate

Participants

Reaction Steps

A mixture of the ester (H) described above (used without further characterization) (4.43 g), cyclopentylacetic acid (1.85 g), 4-(dimethylamino)pyridine (1.76 g), and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (3.26 g), was dissolved in methylene chloride (100 ml), under an atmosphere of nitrogen, and stirred at room temperature for 18 hours. The mixture was poured into 1M hydrochloric acid (25 ml), the separated aqueous layer extracted with dichloromethane (2×100 ml), the combined organic extracts washed with water, brine, dried (MgSO4) and evaporated. The residual oil was crystallized from ethanol to give off-white needles which were recrystallized from methylene chloride/hexane to give methyl 4-[5-(2-cyclopentylacetamido)-1-ethylindol-3-ylmethyl]-3-methoxybenzoate (I) as a white powder (5.12 g, 87%); mp 144°-146° C.; partial NMR (250 MHz, DMSO-d6): 1.17(m, 2H), 1.32(t, 3H), 1.4-1.8(m, 6H), 2.25(m, 3H), 3.82(s, 3H, OCH3), 3.92(s, 3H, OCH3), 3.97 (s, 2H, ArCH2), 4.09(q, 2H, CH2CH3), 9.61(s, 1H, NH).

Provenance & Evidence