Methyl 2,6-dihydr-oxy-3-nitro-benzoate

Crystals of the title compound, C8H7NO6, were obtained by the reaction of methyl 2,6-dihydroxy-benzoate with nitric acid and crystallization of the product from ethyl acetate. In the mol-ecule, the nitro group is essentially coplanar with the attached benzene ring [O - N - C - C = 5.2 (3)°] indicating conjugation with the π-electron system. The meth-oxy group of the ester group is cis with respect to the ortho-nitro-hydroxyl group. The crystal structure is stabilized by intra- and inter-molecular hydrogen bonds. The ortho-nitro-hydr-oxy group forms an intra-molecular hydrogen bond with the nitro group and the para-nitro-hydr-oxy group forms an intra-molecular hydrogen bond with the ester carbonyl function. In addition, there is inter-molecular hydrogen bonding between the ortho-nitro-hydroxyl of one mol-ecule and the O atom of para-nitro-hydroxyl of another mol-ecule.