| 摘要 |
<p>A process for the preparation of 2-chloro-4,5-difluorobenzoic acid and 2,4,5-trifluorobenzoic acid as well as synthetic intermediates useful in and prepared according thereto, comprising reacting a nitrobenzene having formula (II), wherein X is chloro or fluoro, with an appropriate carbanion to form a compound having formula (III) wherein one of Y and Z is chloro and the other is nitro, and R is a radical selected from the group consisting of -CCl3, -CH2NO2, -CH(NO2)R1, -CH(CO¿2R?1)2, -CH(C(O)R2)2, -CH(CN)CO2R1, -CH(CO¿2?R?1)COR2¿ and -COR2 where R1 is alkyl or arylalkyl and R2 is alkyl, aryl or arylalkyl and, where appearing more than once in such a radical, R?1 and R2¿ may be the same or different at each occurrence.</p> |
