反応 #159461

反応方程式

hydrochloric acid

tert-Butyllithium

4-bromo-3,5-dimethylbiphenyl

Trimethylborate

→

3,5-dimethylbiphen-4-ylboronic acid

収率 93.0%

溶媒

tetrahydrofuran

反応条件

後処理

1. 1
   workup.STIRRINGthe resulting mixture is stirred at −78° C. for 30 min
2. 2
   抽出extracted with ether (2×150 ml)
3. 3
   乾燥dried over anhydrous magnesium sulfate
4. 4
   ろ過filtered
5. 5
   その他the filtrate evaporated in vacuo
6. 6
   その他to give a yellow solid
7. 7
   その他The crude product is triturated with iso-hexane
8. 8
   ろ過filtered

実験手順

tert-Butyllithium (1.7 M solution in hexanes, 36.2 ml, 62.6 mmol) is added dropwise to a solution of 4-bromo-3,5-dimethylbiphenyl (7.27 g; 28 mmol) in dry tetrahydrofuran (150 ml) at −78° C. and stirred under an atmosphere of nitrogen for 30 minutes. Trimethylborate (9.54 ml; 84 mmol) is added and the resulting mixture is stirred at −78° C. for 30 min and then allowed to warm to room temperature. The reaction mixture is acidified with aqueous hydrochloric acid and extracted with ether (2×150 ml). The organic layers are combined, dried over anhydrous magnesium sulfate, filtered and the filtrate evaporated in vacuo to give a yellow solid. The crude product is triturated with iso-hexane and filtered to give 3,5-dimethylbiphen-4-ylboronic acid (5.89 g) as a white powder.

出典