2-Methyl-3-(3-methyl-phen-yl)acrylic acid.

The crystal structure of the title compound, C(11)H(12)O(2), consists of dimers which are formed due to inter-molecular O-H⋯O hydrogen bonding. The dimers are linked to each other by C-H⋯O hydrogen bonds, where C-H belongs to the benzene ring and the O atom is of a carbonyl group of an adjoining mol-ecule. There exist two inter-molecular C-H⋯O hydrogen bonds which form five-membered rings. There exist two π-π inter-actions between the benzene rings. The perpendicular distance in these inter-actions are 3.006 and 3.396 Å. There also exist C-H⋯π and C-O⋯π inter-actions.