p-Toluenesulfonic acid → HCID 86757942, compound

Participants

Reaction Steps

p-Toluene sulfonic acid (0.40 g) was added to an ice-cooled solution of 4-Bromo-2-fluoro phenol (205.38, 1.075 mol) in dihydro-2H-pyran (452.23 g, 5.376 moles). The ice bath was removed after 30 min. and the mixture was stirred for two hours and then diluted with methylene chloride (500 ml). The methylene chloride solution was extracted with 10% aqueous KOH solution (3×500 ml), rinsed with water (3×500 ml), dried over MgSO4, filtered and rotavaped. The crude product was further dried overnight over a vacuum pump and then vacuum distilled. The first distillation fraction was unreacted phenol, (52.0 g) followed by a fraction of the protected phenol (212.29 g, 71.8%). The purified product was frozen in dry ice/acetone bath and then allowed to sit in the refrigerator over 2-3 days to obtain the Monomer IA2 intermediate as clear needle shaped crystals, mp=25-27° C., mp of the Monomer IA1 intermediate=62-63° C., TLC (1:1 CH2Cl2/hexane), Rf=0.42.

Provenance & Evidence