Yield:94571-13-8 68%

Reaction Conditions:

Stage #1: p-benzyloxyphenylbromidewith iodine;magnesium in tetrahydrofuran at 20; for 0.5 h;Reflux;Inert atmosphere;
Stage #2: acetone in tetrahydrofuran; for 3 h;Reflux;Inert atmosphere;

Steps:

22.a (a) 2-(4-benzyloxyphenyl)-2-propanol

[0250] 62.3 g (0.25 mol) of4-benzyloxybromobenzene was dissolved in 300 mL of tetrahydrofuran. 6.3 g (0.263 mol) of magnesium metal was added under the protection of argon. A catalytic amount of iodine was added. The reaction mixture was heated and refluxed for 30 minutes. 58 g (1mol) of acetone was added dropwise. After the addition, the reflux reaction was continued for 3 hours. The reaction mixture was cooled to room temperature. Under ice bath cooling, 132 mL of 2M hydrochloric acid was added dropwise, and the tetrahydrofuran and excess acetone were removed under reduced pressure. The remaining aqueous phase was extracted 3 times with ethyl ether (200mL3) and dried over anhydrous magnesium sulfate overnight. The desiccant was removed by filtration, and the filtrate was concentrated to dryness to obtain 38.8 g of the target product with a yield of 68.0%. m/z 228.11.

References:

EP3556435,2019,A1 Location in patent:Paragraph 0250