Synthesis and Crystal Structure of 3-(Trichloroacetyl) Indole

3-(Trichloroacetyl) indole has been synthesized by the reaction of indole with trichloroacetyl chloride in 73% yield, and its crystal structure was determined by X-ray diffraction method. The crystal is of orthorhombic, space group Pnma with a = 20.781(7), b = 6.857(2), c = 7.431(3) (A), V = 1058.8(6) (A)3, Z = 4, Mr = 262.51, Dc = 1.647 g/cm3, λ = 0.71073(A), μ(MoKα) = 0.833 mm(A) 1 and F(000) = 528. The structure was refined to R = 0.0286 and wR = 0.0749 for 1073 observed reflections with I > 2σ(I). It exhibits a characteristic plane structure consisting of all atoms except Cl(2) and Cl(2)A. Two kinds of intermolecular hydrogen bonds are formed: N(1)- H(8A)…O(1) and N(1)H(8A)…Cl(1). There also exist three kinds of π-π stacking in the crystal.