2-(Methoxycarbonyl)phenylboronic acid.

The structure of the title compound, 2(CH3OCO)C6H4B(OH)2 or C8H9BO4, involves two crystallographically independent conformers, A and B, in a 1:2 ratio; molecules of conformer A are located on a crystallographic mirror plane. The most striking difference between the two independent molecules is the opposite orientation of the methoxycarbonyl groups, while the conformations of the boronic acid groups vary more subtly. Molecules of both types are ordered to produce a specific hydrogen-bonding network that can be interpreted in terms of a layer lying parallel to (100). Within the layer, B molecules are linked with each other by two different O-H...O bonds to form an infinite chain where two centrosymmetric dimeric motifs can be distinguished.