Acetic Acid → 5-[5-(4-Fluorophenyl)pentan-2-yl]benzene-1,3-diol

Reaction equation

C[O:2][C:3]1[CH:4]=[C:5]([CH:11]([CH2:13][CH2:14][CH2:15][C:16]2[CH:21]=[CH:20][C:19]([F:22])=[CH:18][CH:17]=2)[CH3:12])[CH:6]=[C:7]([O:9]C)[CH:8]=1.C(O)(=O)C.Br>O>[OH:2][C:3]1[CH:4]=[C:5]([CH:11]([CH2:13][CH2:14][CH2:15][C:16]2[CH:17]=[CH:18][C:19]([F:22])=[CH:20][CH:21]=2)[CH3:12])[CH:6]=[C:7]([OH:9])[CH:8]=1

Participants

Procedure

Fifty grams of the above prepared 2-(3,5-dimethoxyphenyl)-5-(4-fluorophenyl)pentane, 450 ml. of acetic acid and 180 ml. of 48% HBr in water were mixed. While cooling, the mixture was saturated with hydrogen bromide gas (approximately 1/2 hour). The reaction was placed in an 87° bath and stirred for 17 hours. The reaction was then concentrated in vacuo and the residue neutralized with K2CO3 and NaHCO3, extracted with ether, treated with charcoal and MgSO4 and filtered to yield 45 g. of 2-(3,5-dihydroxyphenyl)-5-(4-fluorophenyl)pentane as a brown oil which distills at 180°/0.01 mmHg.