Benzothiophene-3-boronic acid

Uses

• To prepare thienyl substitutedpyrimidine derivatives as potent antimycobacterialcompounds.
• To prepare 3-O-protected 17-heteroaryl-3-hydroxyestra-1,3,5,16-tetraene-16-carbaldehyde, which in turn is used for the synthesis of heteroarenes-annelated estranes.
• As a substrate in the study of metal-free coupling reactions of allylic alcohols with heteroaryl boronic acids.
• As a starting material for the preparation of thienyl based quinoline and pyridine ligands, which are further used to synthesize platinum complexes.

Synthesis

7342-82-7

5419-55-6

113893-08-6

Under nitrogen protection, 10 g (47 mmol) of 3-bromobenzothiophene was dissolved in 100 ml of tetrahydrofuran (THF) and cooled to -60 °C. 36 ml of hexane solution of n-butyllithium (concentration 1.57 mol/L) was slowly added dropwise, and after the dropwise addition, the reaction mixture was continued to be stirred for 1 hour. Subsequently, 13.3 g (71 mmol) of triisopropyl borate was added and stirring was continued for 1 hour. The reaction system was slowly brought back to room temperature and the reaction was quenched by the addition of 50 ml of saturated aqueous ammonium chloride solution. The reaction mixture was extracted with 100 ml of toluene, the organic phase was washed three times (100 ml each) with distilled water and dried over anhydrous magnesium sulfate. The desiccant was removed by filtration and the solvent was removed by concentration under reduced pressure to afford intermediate B-1. 6.9 g (39 mmol, 83% yield) of the target product, benzothiophene-3-boronic acid, was finally obtained.

References