Acetyl chloride → 1-(4-Hydroxy-2-methoxy-5-methylphenyl)ethanone

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Reaction Steps

1.16 ml (16 mmol) Acetylchloride were added within 5 min to a ice cooled suspension of 2.4 g (16.4 mmol) AlCl3 in 5 ml 1,2-dichloroethane under an argon atmosphere. A solution of 1.13 g (8.2 mmol) 5-methoxy-2-methyl-phenol (PCT Int. Appl. WO 2003/084916 A2) in 2.4 ml 1,2-dichloroethane was added within 5 min. The mixture was naturally warmed to ambient temperature, poured after 4 h onto ice water and extracted twice with dichloromethane. The combined extracts were washed with ice water/0.5 M NaOH solution 1/1 and brine and dried over sodium sulfate. Removal of the solvent under reduced pressure gave a yellow oil which was dissolved in a mixture of 3.5 ml methanol, 7 ml THF and 7 ml 1 M LiOH solution. The solution was stirred for 30 min at ambient temperature and the solvent was partially removed under reduced pressure. Ice water/1 M HCl solution 1/1 was added and the solution was extracted twice with ethyl acetate. The combined extracts were washed with brine and dried over sodium sulfate. Evaporation of the solvent left a yellow solid which was crystallized from dichloromethane/methanol/heptane to yield 441 mg (2.45 mmol, 30%) of the title compound as colorless crystals.

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