Chlorobenzene Chlorobenzoyl chloride

Figure 2. Catalytic activities of SO /ZrCK prepared by use of HiSOj ( ) and (NH4) S04 ( >) vs calcination temperature. Yield % of dichlorobenzophenone in acylation of chlorobenzene with o-chlorobenzoyl chloride at 403 K in 3 h.

Acylation of aromatics which had been known to be catalyzed only by AICI3 was found to be effectively catalyzed by solid superacids. As shown in Table 4, SO4 /ZrCL exhibited a high activity for the acylation of chlorobenzene with o-chlorobenzoyl chloride in the liquid phase. The yield is 100% at 406 K in lOh, while the yields over H-ZSM-5 and SiC -ALOj are 0 and 0.17%, respectively [9]. 

Chlorobenzene with sulfur dioxide - 659 Chlorobenzol - 156 Chlorobenzotrifluoride - 659 Chlorobenzoyl chloride - 659 Chlorobenzyl chloride 55, 254, 265 Chlorobromomethane (see Bromochloromethane) Chlorobromopropane - 659 Chlorobutadiene - 357, 825, 840, 861 Chlorobutane (see Butyl chloride) Chlorodifluoromethane - 681 Chlorodiphenylamine - 487 Chlorododecane - 357 Chloroethane (see Ethyl chloride)... 

Obtained by Friedel-Crafts acylation of 3,5-dimethylphenol with 2-chlorobenzoyl chloride in the presence of aluminium chloride in chlorobenzene [1700],... 

Ordinary solid acids such as SiOz —AI2O3 and zeolites are almost or completely inactive for acylation reactions. However, a solid superacid, Zr02 — S04 (cf. Section 3.9) was recendy found to exhibit high activity for the acylation of chlorobenzene or toluene with benzoyl chloride or o-chlorobenzoyl chloride in liquid phase. This was ascertained by separation of the solid superacid from the reaction mixture during a reaction in which the solid superacid acted as the perfect heterogeneous catalyst. 

Catalytic activities of various solid acids for the acylation of chlorobenzene with 0-chlorobenzoyl chloride are shown in Table 4.7. The yield in the case of Zr02 S04 was 100% at 406 K for 10 h, whereas yield in Ae case of ZSM-5 and Si02 — AI2O3 was 0 and 0.17%. In the acylation of toluene with p-chlorobenzoyl chloride, the yield of substituted benzophenone derivatives was 93% at 373 K for 1 h over Zr02 containing 7 wt% of S04 (Table 4.8), while ZSM-5 and SiCfe —AI2O3 did not show any activity under the s[Pg.239]

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