反应详情

A 100-ml flask was charged with 5 ml of toluene and 2.12 g (10 mmol) of 4′-methyl-2-biphenylcarboxylic acid, and they were vigorously stirred. To this mixture was added 0.32 ml (5 mmol) of methanesulfonic acid, and isobutene gas (98 mmol) was introduced thereto at a flow rate of 1.2 liter/min for 2 minutes. The resulting mixture was stirred at room temperature for 20 minutes. After having confirmed that almost all of the peaks ascribed to 4′-methyl-2-biphenylcarboxylic acid disappeared by HPLC, the reaction solution was washed with a 1.5 M aqueous sodium hydroxide, and dried over anhydrous magnesium sulfate. Thereafter, the solution was concentrated by distilling off toluene by using a rotary evaporator, to give 2.52 g of tert-butyl 4′-methyl-2-biphenylcarboxylate as crystals (yield: 94% based on 4′-methyl-2-biphenylcarboxylic acid, purity by HPLC: 99.9%). Incidentally, the obtained compound had the same physical properties as those of the compound obtained in Example II-1.

1. additionwas introduced
2. stirringThe resulting mixture was stirred at room temperature for 20 minutes
3. washthe reaction solution was washed with a 1.5 M aqueous sodium hydroxide
4. dry with materialdried over anhydrous magnesium sulfate
5. concentrationThereafter, the solution was concentrated
6. distillationby distilling off toluene
7. customa rotary evaporator