Triethylamine → 1-Methacryloylindoline-2-carboxylic acid ethyl ester

Participants

Reaction Steps

To a chilled and stirred mixture of 2,3-dihydroindole-2-carboxylic acid ethyl ester (4.78 g., 25.0 mmole), triethylamine (2.7 g., 26.7 mmole), and anhydrous ether (500 ml) was added dropwise methacryloyl chloride (2.9 g., 27.7 mmole) dissolved in a small amount of ether. After the completion of the addition, the ice bath was removed, and the reaction mixture was stirred for 4 hours. The precipitate which separated was removed by filtration, and the filter residue was washed with ether. The combined filtrate and washing were washed with water (two 700-ml portions), then with saline, and dried over anhydrous magnesium sulfate. Evaporation of the solvent under reduced pressure on a rotary evaporator gave the prouct as an oil. The product was purified by preparative HPLC (Prep LC/System 500, Waters Associates), using a micro porasil column eluted with a mixture of hexane (95%) and ethyl acetate (5%). The crude oil may be used directly in the following reaction

Provenance & Evidence