Crystal structure of 3-(2,5-dimethoxyphenyl)propionic acid

In the crystal of the title compound, C₁₁H₁₄O₄, the aromatic ring is almost coplanar with the 2-position methoxy group with which it subtends a dihedral of 0.54 (2)°, while the 5-position methoxy group makes a corresponding dihedral angle of just 5.30 (2)°. The angle between the mean planes of the aromatic ring and the propionic acid group is 78.56 (2)°. The fully extended propionic side chain is in a trans configuration with a C-C-C-C torsion angle of -172.25 (7)°. In the crystal, hydrogen bonding is limited to dimer formation via R₂²(8) rings. The hydrogen-bonded dimers are stacked along the b axis. The average planes of the two benzene rings in a dimer are parallel to each other, but at an offset of 4.31 (2) Å. Within neighbouring dimers along the [101] direction, the average molecular benzene planes are almost perpendicular to each other, with a dihedral angle of 85.33 (2)°.