5-Methyl-1,2-oxazole-3-carboxy-lic acid

Abstract

In the crystal structure of the title compound, C 5H 5NO 3, all the non-H atoms are approximately coplanar: the carboxy O atoms deviating by 0.013 (2) and -0.075 (2) Å from the isoxazole ring plane. In the crystal, the molecules form inversion dimers linked by pairs of O-H⋯O hydrogen bonds and the dimers stack via π-π interactions [centroid-centroid distance = 3.234 (2) Å].