Fluorination ethyl-3-oxobutanoate

Aliphatics Fluorination Investigated in Micro Reactors Cas/liquid reaction 3 [CL 3] Fluorination of ethyl 3-oxobutanoate (ethyl acetoacetate) [15, 16]... 

Two alditols containing fluorine atoms, namely, 2,4-difluoro-l,3-bu-tanediols, were prepared304 by controlled reduction of ethyl 2,4-di-fluoro-3-oxobutanoate with potassium borohydride. 

No metalation is required for the / -fluorination of a-oxo esters.150 Ethyl 3-methyl-2-oxo-butanoate and 3-methyl-2-oxopentanoic acid give the corresponding /f-fluoro derivatives 30 a and 30 b, respectively, in quantitative yield on reaction with A-fluorobis(trifluoromethylsul-fonyl)amine (Id). 3-Fluoro-2-oxobutanoic acid (30c) is exclusively formed by treating 2-oxobutanoic acid with an equimolar amount of reagent Id.150... 

This microflow processing was also demonstrated using other P-keto esters such as ethyl 2-chloro-3-oxobutanoate [309,273] or ethyl 2-methyl-3-oxobutanoate [273]. Five-and six-ring P-ketoester derivatives such as 3-acetyl-3,4,5-trihydrofuran-2-one (1) [273], 2-acetyl cyclohexanone [273] and ethyl 2-oxocydohexane carboxylate (2) [273] were directly fluorinated as well. 

Following extensive laboratory studies at the University of Durham, UK, on the direct fluorination of ethyl 3-oxobutanoate in formic add, scale-out was made from a three- to a nine-channel microstructured reactor, in cooperation with Asahi Glass Co. in Yokohama, Japan [60],... 

Figure 5.27 A 30-channel microstructured reactor for the direct fluorination of ethyl 3-oxobutanoate (by courtesy of the Royal Society of Chemistry) [60].

Scheme 8.2 Fluorination of ethyl 3-oxobutanoate using 9-, 18-and 30-channel microreactors.

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