Sammendrag
?-Fluoroacetophenones can be obtained from the corresponding acetophenones using only Selectfluor in refluxing methanol.[1] The procedure consists of two steps; fluorination yielding the target ?-fluoroketone, 3, its dimethyl acetal, 2; and subsequent hydrolysis to convert 2 to 3, Scheme 1. Scheme 1. Thermal fluorination of acetophenones using F-TEDA-BF4 in methanol, followed by hydrolysis Although simple, an obvious drawback of the thermal method was the prolonged reaction times needed. Moreover, several of the dimethyl acetals, 2, required heating to reflux in the presence of trifluoroacetic acid for several hours for complete conversion to 3. To improve the usefulness of the method, we have investigated the use of microwaves to increase the reaction rates and yields in conversion of 1-arylethanones, 1 to the corresponding 1-aryl-2-fluoroethanones, 3.[2]
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