Title: Benzeneboronic Acid
CAS Registry Number: 98-80-6
CAS Name: Phenylboronic acid
Additional Names: phenylboric acid; phenylboron dihydroxide
Molecular Formula: C6H7BO2
Molecular Weight: 121.93
Percent Composition: C 59.10%, H 5.79%, B 8.87%, O 26.24%
Literature References: Prepd by the reaction of phenylmagnesium bromide with methyl borate: Washburn et al. in Adv. Chem. Ser. 23, entitled "Metal-Organic Compounds," M. Sittig, Ed. (ACS, Washington DC, 1959) pp 102-128. Crystal and molecular structure: S. J. Rettig, J. Trotter, Can. J. Chem. 55, 3071 (1977).
Properties: Crystals from water. Spontaneous conversion to C6H5BO, benzene boronic anhydride or phenylboroxide on standing in dry air, although the best method is by azeotropic dehydration with toluene. mp 215-216° (anhydride). pKa 13.7. Dipole moment 1.72 (dioxane). Soly in water at 25°: 2.5%, benzene: 1.75%, xylene: 1.2%, ether: 30.2%, methanol: 178%.
Melting point: mp 215-216° (anhydride)
pKa: pKa 13.7