New processes that can selectively prepare a-mono or a,a-dichloro ketones and b-ketoesters using 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) are reported. Using silica gel as the catalyst and methanol as the solvent and heating for 1 h under reflux, a-monochlorinated products were selectively obtained in 86-98% yield. However using a deep eutectic solvent (choline chloride: p-TsOH = 1:1) as the solvent and stirring for 45 min at room temperature, a,a-dichlorinated products were selectively obtained in 86-95% yield.

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A New Synthetic Route to Polyfluorobenzyl Alcohol. -The route for the preparation of polyfluorobenzyl alcohols from pentafluorobenzoic acid (I) is shortened by direct reduction of (I) utilizing zinc borohydride as a reductive agent. Reduction of the carboxyl group of (I) by using LiAlH4 as a reductive agent leads to substitution of a fluorine atom by a hydride at the para-position. Tetrafluorobenzyl alcohol (III) can be used as a starting material for the preparation of further benzylic alcohols, e.g. (

Halogenation O 0235Simple and Efficient Methods for Selective Preparation of α-Mono or α,α-Dichloro Ketones and β-Ketoesters by Using DCDMH. -Optimum reaction conditions are studied for the selective preparation of α-mono or α,α-dichloro ketones and β-ketoesters using 1,3-dichloro-5,5-dimethylhydantoin (DCDMH). The structure of some side-products is also reported. -(CHEN, Z.; ZHOU, B.; CAI, H.; ZHU, W.; ZOU*, X.; Green