Hydrochloric Acid → (R)-(2,3-Dihydrobenzo[b][1,4]dioxin-2-yl)methyl 4-methylbenzenesulfonate

Participants

Reaction Steps

3-Chloroperoxybenzoic acid (4.19 g, 17.00 mmol) was added in small portions to 1-[5-fluoro-2-((R)-1-oxiranylmethoxy)-phenyl]-ethanone (2.55 g, 12.13 mmol) in dichloromethane (13 ml) and the reaction mixture was refluxed for 24 hours. The cooled reaction mixture was washed twice with 10% NaHCO3 solution, once with aq NaOH solution and evaporated to dryness. 2M NaOH (10.9 ml, 21.84 mmol) was added to the evaporation residue and the mixture was heated to reflux for 1 hour. The cooled reaction mixture was extracted with dichloromethane and dichloromethane layer was evaporated to dryness. p-Toluenesulfonyl chloride (2.78 g, 14.56 mmol) was added in small portions to the evaporation residue in pyridine (7.5 ml) and the reaction mixture was stirred at RT. After 4 hours 1M HCl (7.5 ml) was added and the mixture was stirred for 1 hour at RT. The reaction mixture was extracted twice with ethyl acetate and the combined ethyl acetate layers were evaporated to dryness. The crude product was crystallized from 2-propanol to yield 2.58 g (63%) of the pure title compound.

Provenance & Evidence