Crystal and molecular structure of 3-phenylisoxazolin-4,5-dione-4-[3′-phenyl-(2′H)Δ3′-isoxazolin-5′-on-4′-yl]hydrazone

The crystal and molecular structure of 3-phenylisoxazolin-4,5-dione-4-3-phenyl-(2H)³-isoxazolin-5-on-4-yl]hydrazone, C₁₈H₁₂N₄O₄, has been determined from X-ray diffractometer data and refined by least-squares methods toR=0.047 for 1413 observed reflections. Crystals of C₁₈H₁₂N₄O₄ are monoclinic:a=13.76(1),b=11.11(1),c=14.10(1) Å, =90.5(1) °,Z=8, space groupC2/c.Among 11 possible tautomeric structures, this compound exhibits a hydrazono structure with intermolecular hydrogen bonds. The phenyl rings make angles of 9.03 ° and 35.12 ° with the planes of the isoxazole rings. Bond distances and angles have reasonable values, and extensive conjugation is evident within the molecule. Close molecular packing is given by layers of molecules approximately parallel to the (001) plane, and in each layer rows of molecules joined by hydrogen bonds run parallel to (¯110).