1-Hydroxybenzotriazole → 4-{5-[4-Phenyl-5-(trifluoromethyl)-2-thienyl]-1,2,4-oxadiazol-3-yl}-1H-indole

Participants

Reaction Steps

4-Phenyl-5-(trifluoromethyl)-2-thiophenecarboxylic acid (310 mg), HOBT (170 mg) and EDCI.HCl (242 mg) were dissolved in DMF (3 ml) and stirred at room temperature for 20 mins. D9 (200 mg) was dissolved in DMF (3 ml) and added to the above solution and stirring continued at room temperature for two hours. The reaction mixture was then heated to 90° C., cooled to RT, stood overnight, re-heated to 80° C. and stirred for 3 hours, cooled to room temperature and evaporated to dryness. The residue was re-dissolved in H2O and extracted with EtOAc (×3) and the combined organic extracts evaporated to dryness. The residue was purified by flash silica chromatography, eluting with a 25-75% mixture of diethyl ether in hexane to give the title compound (265 mg) as a brown solid. A sample of this compound (100 mg) was purified by MDAP to give the title compound (62 mg) as an off white solid. δH (CDCl3, 400 MHz): 7.33-7.36 (2H, m), 7.41-7.42 (1H, m), 7.46-7.52 (5H, m), 7.61 (1H, d), 7.94 (1H, s), 8.06 (1H, d), 8.46 (1H, br s). MS (ES): C21H12F3N3OS requires 411; found 412 (MH+).

Provenance & Evidence