Abstract
3,5-Dimethoxy-2,4-difluorobenzoic acid, as a key intermediate for preparing an impurity of moxifloxacin, was synthesised from 2,3,4,5-tetrafluorobenzoic acid in moderate yield by nitration, methoxyl substitution, reduction of NO2, diazotisation and reduction. The structures of the intermediates and the target compound were identified and determined with IR, NMR and HRMS (ESI).
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