摘要：9-Pyridyl-1,8-dioxo-2,3,4,5,6,7-hexahydroxanthene 3 (C18H17NO3) was prepared by the reaction of 4-pyridinecarboxaldehyde and 1,3-cyclohexanedione using Nafion-H as catalyst. The crystal and molecular structures were studied. The crystal is of orthorhombic, space group Pbcn with a = 20.369(4), b = 14.528(2), c = 9.747(17) (A), V = 2884.3(9) (A)3, Dc = 1.360 g/cm3, Z = 8, F(000) = 1248 and μ(MoKα) = 0.093 mm-1. The final R = 0.0395, wR = 0.1087 for 1458 observed reflections (I > 2σ(I)), and R = 0.1032, wR = 0.1340 for all 2580 reflections. The outer rings of the xanthene groups adopt an almost ideal envelope conformation, and the heterocyclic central ring exhibits a distorted boat conformation. The pyridyl group is rotated with respect to the xanthene system by 87°.

关键词：晶体结构 合成方法 3 4 5 

单位：DepartmentofChemistry; ShanghaiUniversiry; Shanghai200436; China; ResearchCenterofAnalysisandMeasurement; FudanUniversiry; Shanghai200433; China