反应详情

Add oxalyl chloride (17.6 mL, 201.8 mmol) to compound 8c (25 g, 183.7 mmol) and dimethylformamide (3 drops) under neat conditions at room temperature. Observe gas evolution for approximately 2 h. After 5 h, treat the reaction mixture with an additional 0.08 eq of oxalyl chloride (1.2 mL) and stir for 18 h. Use fractional distillation (88°-91° C.) to obtain 24.4 g, 158 mmol of the title compound 8a as an oil in 85% yield. 19F NMR (CDCl3) δ -101.9 (t); 13C NMR (CDCl3) δ 167.3 (t, CO2H), 125.5 (s, C=C), 123.1 (s, C=C), 115.6 (t, CF2), 38.3 (t, CH2); 1H NMR (CDCl3) δ 2.90 (m, 2H), 5.33 (d, 1H), 5.36 (s, 1H), 5.74 (m, 2H).

1. waitAfter 5 h
2. distillationdistillation (88°-91° C.)