Chemical Properties
White to slightly beige crystalline powder
Uses
3-Aminobenzeneboronic acid hemisulfate salt is a boronic acid derivative, which can be used as an intermediate in pharmaceutical synthesis. Adsorbent additive for the chromatographic separation of 3'-terminal polynucleotides from RNA.
Application
3-Aminophenylboronic acid hemisulfate salt is used in the synthesis of:
Phenylboronic acid-functionalized inverse opal hydrogels within microfluidic flow cells for glucose sensing.
Phenylboronic acid-salicylhydroxamic acid-derived complexing reagent for protein immobilization on chromatographic support.
It can also be used in the preparation of phenylboronic acid (PBA) monolayer-modified Au electrode for the voltammetric sensing of uridine and cytidine.
Preparation
3-Aminobenzeneboronic acid hemisulfate salt synthesis: Benzenamine, 3-bromo-N-(diphenylmethylene)- (80,0 g; 0.24 moles) was added to the cryogenic reactor along with 1.4 equivalents of triisopropyl borate and dissolved in tetrahydrofuran. The resulting solution was cooled to -80°C under an inert atmosphere and 1.35 equivalents of n-butyllithium (as a solution in n-hexane) was added maintaining the internal temperature. When complete conversion was achieved, the reaction mixture was added to a dilute mixture of sulfuric acid (1 M) and toluene. The layers were separated to obtain an aqueous solution of 3-aminophenylboronic acid hydrogen sulfate (assay yield: 85%). 3-Aminobenzeneboronic acid hemisulfate salt can be obtained by precipitating a 0.5 M aqueous solution at pH 7.2 (pH corrected with 33% aqueous NaOH) at a temperature of 0-5°C. Filtration and drying under vacuum at 40°C for 8 hours yielded 21.7 g of 3-Aminobenzeneboronic acid hemisulfate salt (0.16 moles; 66% molar yield).
