Yield:-

Reaction Conditions:

with iodine in tetrahydrofuran; for 1.66667 h;Heating / reflux;

Steps:

1

Dried magnesium turnings (4.24 g, 0.55 mole) were stirred with a heavy stirrer bar under argon for 16 hours. A few crystals of iodine were added followed by a solution of 4-bromo-2- fluorotoluene (94.5 g, 0.5 mole) in tetrahydrofuran [THF] (200 ml). This addition took place over about 40 minutes and the solution was allowed to reflux during the addition. The resulting solution was stirred for 1 hour. 4-Bromobenzaldehyde (71.7 g 0.39 mole) in THF (200 ml) was cooled to 0°C then treated with the above Grignard solution. The addition of the Grignard solution took place over 30 minutes and the resulting solution was stirred for 2 hours at room temperature. The reaction mixture was poured slowly into a solution of potassium sodium tartrate (10% solution, 1 L) and extracted with ethyl acetate (EtOAc). The organic solution was dried with brine and sodium sulfate and evaporated. Trituration with hexane gave the title compound (D1) as a white solid (71.8 g, 65%).'H NMR: 8 CDCI3 2.20 (1H, d), 2.24 (3H, m), 5.75 (1H, d), 6.98 (1H, s) 7.05 (1H, m), 7.16 (1H, m), 7.24 (2H, m) 7.47 (2H, m).

References:

WO2005/51397,2005,A1 Location in patent:Page/Page column 21