(1-Ethoxycarbonylethylidene)triphenylphosphorane is an important raw material and intermediate used in organic synthesis, pharmaceuticals, agrochemicals. It?s also a Horner-Wadsworth-Emmons reagent. It can be used for olefination. It can also be utilized for the synthesis of more complex compounds, such as (29S,37S)-isomer of malevamide E, a potent ion-channel inhibitor.
Ethyl 2-(triphenylphosphoranylidene)propionate was prepared this reagent from ethyl 2-bromopropanoate and triphenylphosphine.A 500-mL, one-necked, round-bottomed flask equipped with an egg-shaped magnetic stirring bar is charged with triphenylphosphine (52.46 g, 200.0 mmol), ethyl acetate (130 mL), and ethyl 2-bromopropanoate (26.03 mL, 200.0 mmol). A reflux condenser is attached to the flask and the solution is heated under reflux (oil bath temperature: 75-80 °C) under argon for 24 h. The resulting white precipitate is collected through suction filtration on a Büchner funnel and washed with ethyl acetate (100 mL). The salt is dissolved in dichloromethane (500 mL) and the solution is transferred to a 1-L separation funnel. Aqueous sodium hydroxide solution (2 M, 200 mL) is added and, after vigorously shaking, the organic and aqueous layers are separated. The aqueous phase is extracted with dichloromethane (100 mL). The combined organic phases are washed with brine, dried over anhydrous Na2SO4, filtered, and concentrated at 30 °C under rotary evaporation (20-25 mmHg); drying under vacuum (0.1-0.2 mmHg) affords 54.51 g (75.2%) of ethyl 2-(triphenylphosphoranylidene)propionate as a light-yellow solid, mp 156-158 °C.
