S(Cl)(Cl)=O.[F:5][C:6]([F:25])([F:24])[CH2:7][O:8][C:9]1[CH:17]=[CH:16][CH:15]=[C:14]([O:18][CH2:19][C:20]([F:23])([F:22])[F:21])[C:10]=1[C:11](O)=[O:12].[NH2:26][NH2:27]>CN(C)C=O.C(O)C>[F:5][C:6]([F:25])([F:24])[CH2:7][O:8][C:9]1[CH:17]=[CH:16][CH:15]=[C:14]([O:18][CH2:19][C:20]([F:23])([F:22])[F:21])[C:10]=1[C:11]([NH:26][NH2:27])=[O:12]Thionyl cloride (11.9 g., 100 mmole), 2,6-di(2,2,2-trifluoroethoxy)benzoic acid (2.0 g., 6.3 mmole) and two drops of dimethyl formamide are heated to reflux temperature and maintained at reflux for 4 hours. Unreacted thionyl chloride is removed by distillation on a steam bath at water aspirator pressure. The residue is dissolved in dry tetrahydrofuran and added dropwise to a solution of 95 per cent hydrazine (3.2 g., 100 mmole) in ethanol (15 ml.). The mixture is allowed to sit overnight and evaporate to dryness. The residue is diluted with water and a white solid collected and purified by sublimation (138°-140°/0.2 to 0.5 mm. Hg.) followed by recrystallization from benzene to give 2,6-di-(2,2,2-trifluoroethoxy)benzoic acid hydrazide, m.p. 153°-154° C.
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