Maleic Anhydride → 191014-72-9

Participants

Reaction Conditions

Reaction Steps

Aluminum chloride anhydrous (32.6 g, 0.245 mol.) was added at room temperature and under dry nitrogen atmosphere, to a solution of maleic anhydride (9.6 g, 0.098 mol.) and difluorobenzene (20 ml, 0.195 mol.) in dry dichloromethane. The reaction mixture was heated to reflux for 4 hours; then cooled and quenched with ice/37% hydrochloric acid (100 g/100 mL). Dichloromethane (200 mL) was added, the phases separated and the aqueous layer was extracted twice with dichloromethane (50 mL), the collected organic extracts were washed with 2N HCl and then with brine. The resulting solution was dried (Na2SO4) and evaporated in vacuo to provide the crude product, as deep yellow oily material, which was dissolved in diethyl ether (60 mL). The organic phase was extracted with saturated sodium bicarbonate solution (150 mL), the collected aqueous layers were washed with diethyl ether and cooled at 0° C., then to the alkaline aqueous solution, 37% hydrochloric acid was added on stirring until the pH was 2. The obtained suspension was extracted with ethyl acetate (3×100 mL); the collected organic extracts were washed with brine, dried (Na2SO4) and evaporated in vacuo to provide a yellow solid (11 g). Crystallisation from toluene provided the pure titled compound (7.6 g, 40%) melting at 107-108° C.

Provenance & Evidence