3-(Trifluoromethyl)benzaldehyde → 5-Amino-2-phenoxy-benzoic acid (3-trifluoromethyl-benzylidene)-hydrazide

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Reaction Steps

A mixture of phenol (5.64 g, 60 mmol) and potassium t-butoxide (6.74 g, 60 mmol) in 50 mL 1,4-dioxane was stirred at room temperature for 0.5 h. To the mixture was added 2-chloro-5-nitro-benzoic acid methyl ester (10.78 g, 50 mmol) and the mixture was refluxed overnight. The solvent was evaporated and the residue was purified by chromatography with EtOAc:hexanes, 1:4, as eluant, yielding (11.739 g, 86%) 5-nitro-2-phenoxy-benzoic acid methyl ester. A mixture of 5-nitro-2-phenoxy-benzoic acid methyl ester (2.0 g, 7.32 mmol) in 30 mL ethanol and Pd/C (200 mg) were hydrogenated at 40 psi overnight to yield 5-amino-2-phenoxy-benzoic acid methyl ester (1.672 g, 94%). A mixture of 5-amino-2-phenoxy-benzoic acid methyl ester (0.95 g, 3.9 mmol) and hydrazine (4 mL, 80%) was refluxed for 4 h to yield 5-amino-2-phenoxy-benzoic acid hydrazide (0.722 g, 76%). The title compound was prepared from 5-amino-2-phenoxy-benzoic acid hydrazide and 3-trifluoromethyl-benzaldehyde by a procedure similar to Example 22. 1H NMR (CDCl3): 10.81 (s, 1H), 8.15 (s, 1H), 8.0 (s, 1H), 7.98 (d, J=7.5 Hz, 1H), 7.66 (s, 1H), 7.64 (d, J=7.5 Hz, 1H), 7.53 (t, J=7.2 Hz, 1H), 7.40 (m, 2H), 7.19 (t, J=7.5 Hz, 1H), 7.07 (d, J=7.8, 2H), 6.80 (m, 2H).

Provenance & Evidence