Phenothiazine → 2-(Trifluoromethylsulfonamido)ethyl methacrylate

Participants

Reaction Steps

In a 1-liter three-neck flask equipped with a thermometer, a reflex condenser and a calcium chloride tube were placed 350 g of acetonitrile, 70.7 g (0.699 mol) of triethylamine, 33.1 g (0.200 mol) of 2-aminoethyl 2-methylacrylate hydrochloride and 0.2 g of phenothiazine, followed by cooling to −30o C with stirring. After the inside temperature of the flask reached −30° C., 40.3 g (0.239 mol) of trifluoromethanesulfonyl chloride was introduced as a gas into the slurry over 1 hour. Upon completion of the gas introduction, the reaction solution was stirred for 1 hour and then warmed to room temperature. The solvent (acetonitrile) and the unreacted reaction substrate (trifluoromethanesulfonyl chloride) were evaporated from the reaction solution under a reduced pressure. To the solution was added 1 liter of diisopropyl ether. The resulting slurry was subjected to filtration to filter out a precipitate of triethylamine hydrochloride. The filtrate was washed three times with 200 g of 10% aqueous sodium chloride solution, and then, dried with 40 g of magnesium sulfate. The magnesium sulfate was removed by filtration. After that, 0.2 g of phenothiazine was added to the organic phase. The solvent was evaporated to obtain 22.5 g of a crude reaction product. The crude reaction product was subjected to distillation under a reduced pressure, thereby yielding 9.9 g of target 2-{[(trifluoromethyl)sulfonyl]amino}ethyl 2-methylacrylate as an organic fraction at 105-115° C. /13Pa. The purity of the 2-{[(trifluoromethyl)sulfonyl]amino}ethyl 2-methylacrylate was determined by gas chromatography to be 98.0%. The yield of the 2-{[(trifluoromethyl)sulfonyl]amino}ethyl 2-methylacrylate was 19%.

Provenance & Evidence