1,1'-Carbonyldiimidazole → 2-[(4-ethyl-2-fluorophenyl)amino]-3,4-difluoro-N-(2-hydroxyethoxy)benzamide

Participants

Reaction Steps

The title compound was prepared from the reaction of the product of Step D, 2-[(4-ethyl-2-fluorophenyl)amino]-3,4-difluorobenzoic acid (93 mg, 0.32 mmol) dissolved in dry THF (5 mL), and carbonyldiimidazole (CDI) (102 mg, 0.63 mmol). Within 10 minutes, a bright yellow solution was obtained and conversion to the imidazolide was confirmed by TLC (50% EtOAc/hexanes). A solution of 2-(aminooxy)ethanol (97 mg, 1.26 mmol) in THF (5 mL) was then added and the mixture stirred for 15 hours at room temperature. The reaction solvent was removed under reduced pressure and the residue partitioned between 1 M HCl (50 mL) and EtOAc (50 mL). The EtOAc layer was then washed with water (50 mL) and saturated NaCl solution (50 mL), dried (Na2SO4), and the solvent removed under reduced pressure to afford an oil which was purified by flash column chromatography on silica gel (50% EtOAc/hexanes) to give 2-[(4-ethyl-2-fluorophenyl)amino]-3,4-difluoro-N-(2-hydroxyethoxy)benzamide as a cream solid (65%); m.p. (EtOAc/hexanes) 134–138° C. 1H NMR [400 MHz, (CD3)2SO] δ 11.84 (br s, 1 H), 8.76 (br s, 1 H), 7.43–7.37 (m, 1 H), 7.14–7.02 (m, 2 H), 6.90 (dd, J=8.3, 1.5 Hz, 1 H), 6.83. (td, J=8.6, 4.4 Hz, 1 H), 4.70 (br s, 1 H), 3.86 (t, J=4.9 Hz, 2 H), 3.57 (t, J=4.9 Hz, 2 H), 2.54 (q, J=7.6 Hz, 2 H), 1.15 (t, J=7.6 Hz, 3 H).

Provenance & Evidence