Methyl 2,6-dihydroxy-3-nitrobenzoate

Crystals of the title compound, C8H7NO6, were obtained by the reaction of methyl 2,6- dihydroxybenzoate with nitric acid and crystallization of the product from ethyl acetate. In the molecule, the nitro group is essentially coplanar with the attached benzene ring [ O - N - C - C = 5.2 ( 3) degrees] indicating conjugation with the pi- electron system. The methoxy group of the ester group is cis with respect to the ortho- nitrohydroxyl group. The crystal structure is stabilized by intra- and intermolecular hydrogen bonds. The ortho- nitrohydroxy group forms an intramolecular hydrogen bond with the nitro group and the para- nitrohydroxy group forms an intramolecular hydrogen bond with the ester carbonyl function. In addition, there is intermolecular hydrogen bonding between the ortho- nitrohydroxyl of one molecule and the O atom of para- nitrohydroxyl of another