p-Toluenesulfonic acid → 5-Hydroxy-4'-trifluoromethyltolan

Participants

Reaction Conditions

Reaction Steps

Compound 4 (13.84 g, 40 mmol), CH2Cl2 (75 ml) and MeOH (125 ml) were placed in a 250 ml round-bottomed flask, then TsOH (0.4 g, 0.4 mmol) was added. The reaction mixture was stirred at 30° C. for 1 hour. When the reaction was finished (TLC showed no starting material remaining), the solvent was removed by rotary evaporation and the residue was dissolved in EtOAc and filtered through silica gel. The solvent was removed and the solid was recrystallized from solvents of ethyl acetate and hexane (1:5) to give a pale yellow crystal 9.5 g (90%), mp 131-132° C., δH (CDCl3, 300 MHz): 7.59 (s, 4H, Ar—H), 7.44 (d, J=8.7, 2H, Ar—H), 6.82 (d, J=8.7, 2H, Ar—H), 5.16 (s, 1H, OH).

Provenance & Evidence