Background and overview of preparation and application of 2-bromophenylboronic acid
2-Bromophenylboronic acid is a boronic acid derivative. Boric acid derivatives are widely used in organic synthesis for the formation of carbon-carbon bonds. In the Suzuki coupling, aryl halides and aryl or vinyl borates or boronic acids are coupled using Pd(PPh3)4.
Preparation and application of 2-bromophenylboronic acid
High purity calcium carbonate
O-dibromobenzene (0.5 cm3, 4.15 mmol), THF-Et2O (25 cm3: 25 cm3) solution was cooled to -115°C. Quickly add precooled (-78°C) t-BuLi (5.9 cm3, 8.73 mmol). The yellow reaction mixture was stirred at -115°C for 35 minutes. Add precooled (-78° dimethyl sulfoxide; C) B(OMe)3 (5 cm3, 44 mmol) in Et2O (10 cm3). Stir for two hours at -115 to -105°C. Quench the reaction with 5 cm3EtOH-concentrated hydrochloric acid (8:2) at -115°C. Warm slowly to room temperature and recrystallize from water (150 cm3) to give 2-bromophenylboronic acid.
Preparation and application of 2-bromophenylboronic acid
CN201910088264.X can be used to prepare a triarylmethane derivative. Due to the particularity of its structure, triarylmethane derivatives are widely used in medicinal chemistry, dye industry and materials science, and are a very important class of compounds.
A synthesis method of triarylmethane derivative ((4-dimethylaminophenyl)(2-hydroxyphenyl)(2-bromophenyl)methane), including the following steps: sequentially add 1.0mmol (0.122 g) Salicylaldehyde, 1.0mmol (0.200g) o-bromophenylboronic acid, 1.2mmol (0.102g) piperidine, 1.2mmol (0.145g) N,N-dimethylaniline and 0.5mmol (0.127g) catalyst (catalyst Add 10 ml of I2) into a dry round-bottomed flask, then add 1 ml of chlorobenzene as the solvent, heat to reflux at 100°C, and monitor the reaction with TLC. After the reaction is complete, cool to room temperature and add to the reaction system. Add 30 ml of ethyl acetate to the solution, and wash with 20 ml of water and 10 ml of saturated brine in sequence. The organic phase is dried over anhydrous sodium sulfate and filtered. After a large amount of solvent is evaporated under reduced pressure, the residue is separated by column chromatography, using n-hexane and Ethyl acetate was used as the eluent. The solvent was evaporated and dried to obtain the target compound. The reaction yield was 76%.
References
[1] Matthias, Filthaus, Iris, et al. Supramolecular structures and spontaneous resolution: the case of ortho-substituted phenylboronic acids.[J]. Organic & Biomolecular Chemistry, 2008.
[2] [Chinese invention] CN201910088264.X Synthesis method of triarylmethane derivatives
