1-Hydroxybenzotriazole → 5-(4-Hydroxy-phenyl)-isoxazole-3-carboxylic acid {2-oxo-2-[4-(2-trifluoromethyl-benzoyl)-piperazin-1-yl]-ethyl}-amide

Participants

Reaction Steps

DIPEA (65 mg, 0.51 mmol) was added to a stirred solution of 2-amino-1-[4-(2-trifluoromethyl-benzoyl)-piperazin-1-yl]-ethanone TFA salt. (87 mg, 0.20 mmol) in DMF (1 mL). HOBT (28 mg, 0.20 mmol) and EDCI.HCl (39 mg, 0.20 mmol) were then added at room temperature. After 2 minutes, 5-(4-hydroxyphenyl)-isoxazole-3-carboxylic acid (35 mg, 0.17 mmol) was added and the resulting mixture was stirred at room temperature for 4 hrs. Cold water (20 mL) was then added and the product was extracted with EtOAc and the organic layer was washed with brine. The organic phase was dried over Na2SO4 and concentrated under reduced pressure to afford 23 mg (26.7% yield) of 5-(4-hydroxy-phenyl)-isoxazole-3-carboxylic acid {2-oxo-2-[4-(2-trifluoromethyl-benzoyl)-piperazin-1-yl]-ethyl}-amide. LCMS Purity: 93.77%, HPLC Purity: 90.43%, 1H NMR (DMSO-d6): δ 10.1-10.0 (s, 1H), 8.6-8.5 (s, 1H), 8.0-7.6 (m, 5H), 7.5 (bs, 1H), 7.1 (s, 1H), 6.8 (d, 2H), 4.2-4.1 (d, 2H) 3.8-3.7 (m, 2H), 3.6 (m, 2H), 3.4 (m, 2H), 3.2-3.1 (m, 2H).

Provenance & Evidence