Synthesis of (2-chlorophenyl)(phenyl)methanones and 2-(2-chlorophenyl)-1-phenylethanones by Friedel–Crafts acylation of 2-chlorobenzoic acids and 2-(2-chlorophenyl)acetic acids using microwave heating

• Published in: Tetrahedron letters 2011-05, Vol.52 (20), p.2594-2596
• Main Authors: Mahdi, Jasia, Ankati, Haribabu, Gregory, Jill, Tenner, Brian, Biehl, Edward R.
• Format: Article
• Language: English
• Subjects: 2-Chlorobenzoic acids and 2-(2-chlorophenyl)acetic acids; Acetic acid; Acylation; Aluminum chloride catalysts; Catalysis; Catalysts: preparations and properties; Chemistry; Chlorides; Chromatography; Exact sciences and technology; Ferric; Friedel–Crafts acylation; General and physical chemistry; Heating; Ketones; Microwave heating; Microwaves; Noncondensed benzenic compounds; Organic chemistry; Preparations and properties; Purification; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2011.03.052

Several 2-(2-chlorophenyl)-1-phenylethanones and (2-chlorophenyl)(phenyl)methanones were prepared by the Friedel–Crafts acylation reaction of 2-(2-chlorophenyl) acetic acids and 2-chlorocarboxylic acids, respectively, in the presence of cyanuric chloride, pyridine, and AlCl3 or FeCl3 using microwave heating. The yields of the ketones were significantly higher than those obtained using conventional heating. In addition, similar reactions carried out with the less inexpensive and less toxic FeCl3 gave titled ketones in comparable yields. Interestingly, the FeCl3 catalyzed reactions gave pure ketones (no chromatographic purification required), whereas the AlCl3 catalyzed reaction gave impure product that required chromatographic purification.