Hydrochloric Acid → 1,4-Bis(4-fluorophenyl)but-2-ene-1,4-dione

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Reaction Steps

To a solution of fluorobenzene (0.52 mols, 50 g, 48.83 mL) in carbon disulfide (500 mL) was added aluminium chloride (0.651 mmol, 86.8 g). The resulting suspension was gently refluxed under an atmosphere of nitrogen. Fumaryl chloride (0.26 mols, 28.2 mL) was added over a period of 15-20 minutes. The resulting dark orange reaction mixture was refluxed for 18 h and the residue was poured into crushed ice (1 Kg) and concentrated hydrochloric acid (15.0 mL). The semi-solid was filtered off, washed with ether and ethanol, digested in ethanol, and recrystallized from ethyl acetate/ethanol to give pale yellow needles of compound 1 in 96% yield, m.p. 115°-116° C. 1H NMR: 7.14-7.18 (t, 2H, Jmeta =1.9 Hz, C6H4), 7.96 (s, 2H, CH=CH), 8.05-8.12 (q, 6H, J=2.2 Hz, C6H4); ms m/e (Cl with NH3 ), 290(NH3 +H+M), 273(M+1), 272(M); HRMS m/e calcd for C16H10O2F2 273.0727, found 273.0727.

Provenance & Evidence