117896-99-8

1. Boron tribromide (53 ml, 0.561 mol) was added dropwise to a dichloromethane solution (500 ml) of 1,1,1-trifluoro-4-(4-methoxyphenyl)butan-2-one (43.5 g, 0.187 mol) at -78 °C. 2. The reaction mixture was transferred to a 0°C ice bath and stirring was continued for 3 hours. 3. Ice water (200 ml) was added slowly and dropwise over 1 hr to quench the reaction. 4. The aqueous phase was saturated with solid sodium chloride and extracted with dichloromethane (500 ml) and ether (500 ml) respectively. 5. The organic layers were combined and dried with anhydrous magnesium sulfate and subsequently concentrated under vacuum. 6. Purification of the residue by ball-ball distillation (96-100 °C, 0.2 mmHg) afforded 1,1,1-trifluoro-4-(4-hydroxyphenyl)butan-2-one (34.4 g, 84%) as a yellow liquid, which solidified on standing. 7. Elemental analysis results (C10H9F3O2-0.5H2O): calculated value C 52.87%, H 4.44%; measured value C 52.93%, H 4.53%.

[1] Patent: US6350892, 2002, B1
[2] Patent: US6255496, 2001, B1
[3] Chemical Science, 2018, vol. 9, # 30, p. 6340 - 6347
[4] Analytical Chemistry, 2018, vol. 90, # 15, p. 9301 - 9307