Synthesis of α-chloroketones from secondary alcohols using dichloramine-T

Abstract

Various secondary alcohols reacted with dichloramine-T in $CH_3CN$ at $40^{\circ}C$ to give the corresponding α-chloroketones in good yields under mild and neutral conditions. This new method for the synthesis of α-chloroketones from secondary alcohol was accomplished by oxidation of secondary alcohols with dichloramine-T and then $\underline{in}$ $\underline{situ}$., followed by α-chlorination of the ketone. The reaction rate is strongly dependent on the nature of the substrate and substituent on the pheny ring moiety. Among the various solvents, acetonitrile showed by best results. The key to the success of this method appears to use aprotic polar solvent such as acetonitrile.