Studies On The Improvment Of Chlorination Of Benzyl Alcohols Using Imidoyl Chloride Catalyzed By DMSO

We report a mild and efficient procedure for converting benzyl alcohols into the corresponding halides in this paper. The chlorination reagent was N-phenyl- benzimidoylchloride and the catalyst was DMSO. Anhydrous chloroform was used as solvent. We have explored the effects of various factors of reaction, optimizing the reaction conditions and further enhancing the yields. When DMSO was 0.05eq, N-phenylbenzimidoylchloride was 2～3eq , the reaction temperature was controlled at room temperature, and the reaction time took 2～4 days, the yield of chlorination was 54～82%. The yield of chlorination of 1-(4-benzyloxyphenyl) ethanol was 76 % for 2 days, and 1-(4-bromophenyl) ethanol 82% for 3 days, and 1-(4-fluorophenyl) ethanol 54% for 4 days. This showed that the electron density on the phenyl substituents influenced the reaction rate and yield to a certain extent. Higher electron density leads to faster reaction rate, and higher yield.In conclusion, we have established a new method of chlorination of benzyl alcohols. The yields are higher, reaction conditions are milder, and reaction time is shorter. It is an effective chlorination method for benzyl alcohols.