Diaryl with oxalyl chloride

The AICI3-mediated chlorocarbonylation of arenes with oxalyl chloride has been used in the preparation of symmetrical and unsymmetrical diaryl ketones 1266 [945, 946],... 

Tab. 4.43. Synthesis of diaryl ketones with oxalyl chloride [946].

Under Friedel-Crafts conditions (AICI3, CS2), oxalyl chloride reacts with aromatic hydrocarbons to give carbonyl chlorides, which are hydrolyzed by water to give carboxylic acids. The AICI3-mediated chlorocarbonylation of arenes with oxalyl chloride has been used in the preparation of symmetrical and unsymmetrical diaryl ketones [946] (see also Section 4.3.6). 

Synthesis.—Another report has appeared of the condensation of sulphur di-imides ArN=S=NAr with oxalyl chloride to give, in this case, 2,5-diaryl-l-arylimino-1,2,5-thiadiazolidine-3,4-diones (174). 3-Chloro-4,4-dimethyl-A -1,2,5-thiadiazoline 5-oxide (175) and the dioxide (176) arise in good yield from the interaction of 2-amino-2-cyanopropane with thionyl or sulphuryl chloride, respectively. The halogen is replaced by basic groups. ... 

The most important method for the preparation of aryl ketones is known as Friedel-Crafts acylation. The reaction is of wide scope. Reagents other than acyl halides can be used," including carboxylic acids," anhydrides, and ketenes. Oxalyl chloride has been used to give diaryl 1,2-diketones." Carboxylic esters usually give alkylation as the predominant product (see 11-11)." A-Carbamoyl p-lactams reacted with naphthalene in the presence of trifluoromethanesulfonic acid to give the keto-amide." ... 

A diaryl cyclopropenone (171) catalyses nucleophilic substitution of alcohols, for example, chlorination. Employing an activator such as oxalyl chloride [(COCl)2], a cyclopropenium salt (172) is generated and adds to the alcohol (to give 173), with the nucleophile then generating the product (with inversion of configuration), and regenerating the original cyclopropenone (171). The method shows considerable promise for dehydrations. ... 

Typical procedure. Symmetrical diaryl ketone [946] In a 100-mL round-bottomed flask with a side-arm, oxalyl chloride (1.05 mL, 12 mmol) was added dropwise over a period of 5 min to a solution of p-xylene (1.23 mL, 10 mmol) in dichloromethane (50 mL) at 5 °C. Aluminum chloride (1.33 g, 10 mmol) was then added portion-wise over 5 min to give a yellow suspension. The reaction mixture was allowed to warm to room temperature and stirred for 1 h, during which time dissolution of the solid and gas evolution were observed. A second equivalent of p-xylene (1.23 mL, 10 mmol) was then added dropwise over a period of 5 min, and the reaction mixture was stirred for 13 h at room temperature. It was then chilled in an ice/ water bath, and water (25 mL) was added dropwise over a period of 10 min. The layers were separated, and the aqueous layer was extracted twice with dichloro-... 

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