Crystal and molecular structure of dimethylpyrazolo [1,2-a]pyrazolo[1,2-b]benzotriazole-3,4-dicarboxylate,C15H13N3O4

Crystals of dimethyl pyrazolo [1,2-a]pyrazolo[1,2-b]benzotriazole-3,4-di-carboxylate, C₁₅H₁₃N₃O₄, are triclinic:a=9.268(10),b=19.367(50),c=8.821(9) Å,=96.76(18),=115.39(10),=80.17(22)°,Z=4, space group P¯1 with two independent molecules in the asymmetric unit. The crystal and molecular structures have been determined from X-ray diffractometer data by direct methods, and refined by least-squares methods toR=0.047 for 2653 observed reflections. In a least-squares fitting procedure the two independent molecules show an almost perfect resemblance, except for the orientations of the 3-carbomethoxy groups. Their chiral structure is described asS. There is an appreciable puckering of the condensed five-membered rings. Bond distances and angles are found to be not comparable with those in the literature, and are discussed. The carbomethoxy groups of the same molecule show a different slant, owing to overcrowding. Close molecular packing is afforded by layers of molecules approximately parallel to the (001) plane.