Diethyl Oxalate → N-{4-[3-(4-fluorobenzenesulfonyl)-4-hydroxyphenoxy]-3,5-dimethylphenyl}oxamic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of the title D compound, 4-(4-amino-2,6-dimethylphenoxy)-2-(4-fluoro-benzenesulfonyl)phenol (0.64 g, 1.65 mmol) and 2 mL of diethyl oxalate is heated at 180° C. for 3 h. The reaction is cooled to RT and diethyl oxalate is removed under vacuum. Chromatography on silica (eluant; EtOAc/hexane —1/3→2/3) affords N-{4-[3-(4-fluoro-benzenesulfonyl)-4-hydroxyphenoxy]-3,5-dimethylphenyl}oxamic acid ethyl ester: NMR (CDCl3) 1.46 (t, 3H, J=7.5), 2.06 (s, 6H), 4.42 (q, 2H, J=7.5), 6.90-6.98 (m, 3H), 7.22 (app t, 2H, J=8.3),7.40 (s, 2H), 7.87-7.93 (m, 2H), 8.87 (br s, 1H); ESI-MS 486 [M-1]−.

Provenance & Evidence