Issue in Honor of Prof. (Mrs.) Asima Chatterjee ARKIVOC 2003 (ix) 34-38 Ceric ammonium nitrate catalyzed mild and efficient α-chlorination of ketones by acetyl chloride Subhas Chandra Roy,* Kalyan Kumar Rana, Chandrani Guin, and Biplab Banerjee Department of Organic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Calcutta-700032, India E-mail: ocscr@mahendra.iacs.res.in Dedicated to Professor (Mrs.) A. Chatterjee on her 85 th birthday (received 25 Nov 03; accepted 15 Jan 04; published on the web 20 Jan 04) Abstract A mild and efficient method of α-chlorination of ketones has been developed using acetyl chloride as the chlorinating agent in the presence of a catalytic amount of ceric ammonium nitrate in good yield. The reaction is highly chemo and regio selective in nature. Keywords: Ceric ammonium nitrate, ketones, α-chlorination, acetyl chloride Introduction α-Chlorination of carbonyl compounds is one of the major investigated organic reactions and it has been discussed in a wealth of chemical literature. A wide variety of useful reagents and procedures are available for the synthesis of α-chloroketones 1 which are versatile intermediates in organic synthesis (such as Cornforth olefin synthesis, Favorskii rearrangement etc) 2 particularly for the synthesis of heterocyclic compounds. Direct side chain chlorination of ketones using chlorine or sulfuryl chloride 3 is a commonly accepted procedure. But this protocol is not reliable for activated aromatic substrates 4 such as hydroxy acetophenones or with electron rich heterocyclic systems where concurrent nuclear halogenation is facile. 5 Recent reports have been found to deal with the use of aqueous TiCl 3 , 6 hexachloro-2,4-cyclohexadienone, 7 benzyl trimethylammonium dichloroiodate, 8 N-chlorosuccinimide, 9 α-chloroalkyllithium 10 etc for the α- chlorination of ketones. ISSN 1551-7012 Page 34 © ARKAT USA, Inc