| 摘要 |
NEW MATERIAL:A compound shown by the formula I (R is lower alkyl; X is halogen). EXAMPLE:3-Chloro-2,4,5-triflurobenzoylacetic acid ethyl ester. USE:An intermediate for producing an antimicrobial agent. PREPARATION:A compound shown by the formula II is condensed with a malonic acid dialkyl ester in the presence of a magnesium alcoholate in an inert solvent such as an ether, toluene, etc. at -50-50 deg.C, preferably -20- room temperature for 10 minutes-20 hours, to give a compound shown by the formula III. This compound is not purified, refluxed in an aqueous solution of an acid containing a catalytic amount of p-toluenesulfonic acid for 30 minutes - 20 hours so that ir is decarbonated, to give a compound shown by the formula I. The compound shown by the formula I can be converted into a compound shown by the formula IV which is extremely useful as an antimicrobial agent.
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