反应详情

The starting materials for the present invention are known, or if new, may be prepared from known materials by known means. Thus, ethyl 1-cyclopropyl-6,7,8-trifluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylate is prepared as described in Belgian Pat. No. 899,399 or No. DE3318145. Alternatively, it may be prepared by a series of reactions starting from 2,3,4,5-tetrafluorobenzoic acid. The sodium salt of 2,3,4,5-tetrafluorobenzoic acid is reacted with oxalyl chloride and the product condensed with diethyl malonate in the presence of magnesium turnings to afford after hydrolysis 2,3,4,5-tetrafluorobenzoylacetic acid, ethyl ester. This compound is, in turn, treated with triethylorthoformate and acetic anhydride, followed by cyclopropylamine to afford 2-(2,3,4,5-tetrafluorobenzoyl)-3-cyclopropylamino acrylic acid, ethyl ester, which is then ring closed to give the desired starting material. The corresponding methyl ester is prepared using dimethylmalonate in the sequence described above.

1. customif new, may be prepared
2. customAlternatively, it may be prepared by a series of reactions
3. customto afford