Triethylamine → 5-((E)-2-Ethoxycarbonyl-vinyl)-1H-indole-2-carboxylic acid

Participants

Reaction Steps

5-Bromoindole-2-carboxylic acid (400 mg, 1.66 mmol) and tri-O-tolylphosphine (96 mg, 0.32 mmol) were added to a microwave tube. Ethyl acrylate (0.56 ml, 5.6 mmol), Et3N (0.92 ml, 6.6 mmol), acetonitrile (2.5 ml) and Pd(OAc)2 (40 mg, 0.18 mmol) were added. The reaction was placed in a CEM microwave at 150 W, 90° C. for 30 minutes with 5 min ramp time. EtOAc was added and the reaction mixture filtered through celite. The celite pad was washed with DCM and the combined organic fractions removed to give a yellow solid. The solid was redissolved in DCM and extracted into saturated sodium hydrogen carbonate. The aqueous layer was washed with DCM and diethyl ether. The aqueous basic layer was acidified with 2M HCl (pH=5) and the product extracted into EtOAc. The solvent was removed to give the required product (370 mg, 86% yield). LCMS purity 86%, m/z 260 [M++H]+

Provenance & Evidence