反应详情

温度

0 °C

Compound 25 of the present invention may be prepared according to Scheme A as follows. A slurry of 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzoic acid (Compound A1, 1.5.0 g; 52.8 mmol) and 100 μL of dimethylformamide catalyst in 250 mL of anhydrous dichloromethane is allowed to cool to 0° C. Oxalyl chloride (9.2 mL, 105.5 mmol, 2.0 eq.) is added to this slurry over 3 minutes. The reaction mixture is then allowed to warm to room temperature, and is stirred for 16 h. The resultant yellow solution is concentrated in vacuo, azeotroped several times with anhydrous dichloromethane (2×50 mL) and dried under high vacuum for 2 hrs to give 15.5 g of 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzoyl chloride (Compound A2) as a white solid (97%): 1H NMR (CDCl3) δ 7.23-7.38 (m, 2H), 7.58-7.71 (m, 2H), 8.22-8.29 (m, 2H), 8.50 (d, J=7.8 Hz, 1H), 8.91 (t, J=1.6 Hz, 1H).

1. temperatureto warm to room temperature
2. concentrationThe resultant yellow solution is concentrated in vacuo
3. customazeotroped several times with anhydrous dichloromethane (2×50 mL)
4. customdried under high vacuum for 2 hrs