Crystal and molecular structure of the α-modification of 2-methyl-3,5-dinitrobenzamide (coccidine)

Two crystalline forms of coccidine (α from water, acetone, and aqueous ethanol; β from ethanol) that melt without decomposition at 180-181 and 176177°C, respectively, are isolated by recrystallization of the commercial material. The x-ray structure of the a -form is solved (R = 0.053). The molecule of α-coccidine is nonplanar. The amide group is rotated relative to the plane of the benzene ring by 75.3°; the nitro groups, by 14.1 and 22.8°, respectively. The molecules in the crystal are linked into centrosymmetric H-dimers [N...O distance in N-H...O amide H-bonds is 2.923(2) A] that form a zigzag array