Journal of Organic Chemistry 2006-12-22

2-Chloro-2,2-difluoroacetophenone: a non-ODS-based difluorocarbene precursor and its use in the difluoromethylation of phenol derivatives.

Laijun Zhang, Ji Zheng, Jinbo Hu

Index: J. Org. Chem. 71 , 9845, (2006)

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Abstract

A novel and non-ODS-based (ODS = ozone-depleting substance) preparation of 2-chloro-2,2-difluoroacetophenone (1) was achieved in high yield by using 2,2,2-trifluoroacetophenone as the starting material. Compound 1 was found to act as a good difluorocarbene reagent, which readily reacts with a variety of structurally diverse phenol derivatives 4 in the presence of potassium hydroxide or potassium carbonate to produce aryl difluoromethyl ethers 5 in good yields. This new and easy-to-handle synthetic methodology offers an environmentally friendly alternative to other Freon- or Halon-based difluoromethylating approaches.