Collect. Czech. Chem. Commun. 2002, 67, 1416-1420

Fluorination of Methyl 3-Oxopentanoate (MOP) Using Difluorobis(fluoroxy)methane, BDM

Wade H. Bailey III, William J. Casteel, Jr. and Robert G. Syvret*

Air Products and Chemicals, Inc., Allentown, PA 18195, U.S.A.


Difluorobis(fluoroxy)methane, BDM, is an electrophilic fluorinating agent that is capable of affecting selective monofluorination of 1,3-dicarbonyls such as diketones and ketoesters with very high regioselectivity. For example, in highly acidic anhydrous HF (AHF) solvent, fluorination of methyl 3-oxopentanoate (MOP) with BDM provides methyl 2-fluoro-3-oxopentanoate (MFOP) with 100% conversion and 95% selectivity. In mixtures of HF and methanol, fluorination conversions and selectivity are markedly lower. In comparison, direct fluorination of MOP with dilute F2 typically affords a fluorinated product that is less pure, being contaminated with radical fluorination byproducts that are difficult to separate. Fluorination of MOP with dilute mixtures of BDM and F2 is generally more selective than using dilute F2 alone.

Keywords: Electrophilic fluorination; Fluoroxy compounds; Dicarbonyl fluorination; Fluorinated compounds; Keto esters.

References: 16 live references.