Key indicators: single-crystal X-ray study; T = 298 K; mean (C-C) = 0.003 Å; R factor = 0.033; wR factor = 0.063; data-to-parameter ratio = 12.9.In the title Schiff base, C 19 H 19 N 3 O 2 , the dihydropyrazole ring is essentially planar, with an r.m.s. deviation of 0.0289 Å for the fitted atoms. This ring makes dihedral angles of 41.8 (2) and 51.1 (3) with the phenyl and benzene rings, respectively. In the crystal structure, there is one intramolecular O-HÁ Á ÁN hydrogen bond. M r = 321.37 Monoclinic, P2 1 =n a = 7.5655 (19) Å b = 7.5713 (19) Å c = 29.146 (7) Å = 92.006 (4) V = 1668.5 (7) Å 3 Z = 4 Mo K radiation = 0.09 mm À1 T = 298 (2) K 0.34 Â 0.28 Â 0.17 mm
Data collectionBruker APEX area-detector diffractometer Absorption correction: multi-scan (SADABS;Sheldrick, 1996) T min = 0.972, T max = 0.986 9793 measured reflections 2820 independent reflections 1464 reflections with I > 2(I) R int = 0.039