Tributylphosphine → 4-[1-(2,6-Dimethyl-4'-trifluoromethyl-biphenyl-4-yloxy)-3-methyl-butyl]-benzoic Acid Methyl Ester

Participants

Reaction Conditions

Reaction Steps

Methyl 4-(1-hydroxy-3-methylbutyl)benzoate (44.00 g, 197.94 mmol) is dissolved in toluene (1.12 L) and the batch temperature is adjusted to 0° C. Solid azodicarboxylic acid dipiperidine (74.92 g, 296.92 mmol) is added to the reaction solution. Tri-n-butylphosphine (78.0 mL, 296.92 mmol) is added to the reaction solution drop-wise maintaining a batch temperature at 0° C. 2,6-Dimethyl-4′-(trifluoromethyl)biphenyl-4-ol (65.92 g, 237.53 mmol), dissolved in toluene (1 L), is added to the reaction drop-wise maintaining the batch temperature of 0° C. The reaction mixture is warmed to 25° C. and stirred approximately 16 h. The reaction is analyzed by TLC 30% EtOAc in hexanes. Product rf=0.63, carbinol rf=0.34, and the biaryl rf=0.39. The reaction is continued until no methyl 4-(1-hydroxy-3-methylbutyl)benzoate is observed by TLC. Upon reaction completion, the solvent is removed by vacuum distillation and replaced with hexane. The mixture is chromatographed using silica and is eluted with hexanes. The fractions, containing the product, are concentrated to 85.89 g (92.2%) of a viscous oil under reduced pressure at 45° C. 1H NMR (400 MHz, DMSO-d6): δ 7.92 (d, 2H), 7.72 (d, 2H), 7.55 (d, 2H), 7.29 (d, 2H), 6.68 (s, 2H), 5.44 (dd, 1H), 3.81 (s, 3H), 1.83 (m, 1H), 1.82 (s, 6H), 1.75 (m, 1H), 1.52 (m, 1H), 0.94 (dd, 6H).

Provenance & Evidence