4-Chlorobenzoyl chloride → 1-(4-Chlorobenzoyl)-2-chloro-4,6-dimethylbenzene

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A stirred, 0° C. solution of 1-chloro-3,5-dimethylbenzene (10.9 g, 77.2 mmol) and 4-chlorobenzoyl chloride (13.6 g, 77.2 mmol) in carbon disulfide (165 ml) was treated with aluminum chloride (11.4 g, 85.0 mmol) in portions over 15 minutes. The mixture was stirred 15 minutes at 0° C., 60 minutes at ambient temperature, 20 hours at reflux and 3 days at ambient temperature. The mixture was cooled to 0° C. and quenched by addition of ice (250 g) followed by concentrated hydrochloric acid (60 ml). The mixture was extracted twice with diethyl ether and the combined extracts were washed with water (3X), saturated aqueous sodium carbonate, and brine, dried over anhydrous magnesium sulfate, and evaporated to dryness of 30° C. under vacuum. The residue was chromatographed in three approximately equal batches on silica gel (500 g) eluted with 97:3 (v/v) hexane-ethyl acetate using a preparative high performance liquid chromatograph to provide 7.3 g (34%) 1-(4-chlorobenzoyl)-2-chloro-4,6-dimethylbenzene, m.p. 84°-87° C. [IR (neat): 2100, 1660 cm-1 ; 60 MHz 'H NMR (CDCl3): 2.11 s (3H), 2.34 s (3H), 6.94 bs (1H), 7.04 bs (1H), 7.34 dm (J= 9 Hz, 2H), 7.70 dm (J=9 Hz, 2H)] and 3.4 g (16%) 1-(4-chlorobenzoyl)-4-chloro-2,6-dimethylbenzene, m.p. 41°-52° C. [IR (neat): 2100, 1660 cm-1 ; 60 MHz 'H NMR (CDCl3) 2.08 s (6H), 7.07 s (2H), 7.38 dm (J=9 Hz, 2H), 7.69 dm (J=9 Hz,2H)].

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