ethyl 6-fluorobenzofuran-3-carboxylate synthesis

Yield:863250-72-0 26%

Reaction Conditions:

with water;dimethyl sulfoxide;sodium chloride at 160; for 4 h;

Steps:

4.D

109 (40 g, 142.7 mmol) is dissolved in 300 ml of a DMSO and after addition of sodium chloride (16.7 g, 285.4 mmol) and water (5.1 ml) the mixture is stirred for 4h at 160°C (temperature of reaction mixture). Then the mixture is allowed to cool down and evaporated at high vacuum. The residue is dissolved in ethyl acetate, washed with water and brine and dried over sodium sulfate. Evaporation gave 14.8 g of an red oil, which is further purified by filtration over silica gel (ethyl acetate/hexanes 2: 8). Yield: 7. 8 g (26%) of a yellow solid. MS (ESI) : 208 [M] +, 1 H-NMR (DMSO-d6) : 6 (ppm) 8.77 (s, 1H), 7.92 (dd, 1H), 7.68 (dd, 1H), 7.29 (ddd, 1H), 4.35 (q, 2H), 1.32 (t, 3H).

References:

WO2005/77932,2005,A2 Location in patent:Page/Page column 101