title: 5-Methyl-isoxazole-4-carboxylic acid.
abstract: In the title compound, C(5)H(5)NO(3), the mol-ecule lies on a crystallographic mirror plane with one half-mol-ecule in the asymmetric unit. An intramolecular C-H⋯O inter-action is present. In the crystal, strong inter-molecular O-H⋯N hydrogen bonds result in the formation of a linear chain structure along [100], and there are also weak C-H⋯O hydrogen bonds between the chains which help to stabilize the crystal packing.
authors.forename: De-Cai
authors.initials: DC
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Wen-Yuan
authors.initials: WY
authors.lastname: Wu