Crystal structure and conformation study of N‐methyl‐t‐3‐methyl‐r‐2, c‐6‐diphenylpiperidin‐4‐one thiosemicarbazone

Thiosemicarbazones are having the ability to bind with metal and inhibit the enzyme ribonucleoside diphosphate reductase (RDR), an enzyme which is involved in the synthesis of DNA precursors in the mammalian cells. The title compound N‐methyl‐t‐3‐methyl‐r‐2, c‐6‐diphenylpiperidin‐4‐one thiosemicarbazone (NMMDPT), CCDC 218052, was prepared using Mannich reaction and characterized by X‐ray diffraction methods. The crystal data are: C20H24N4S; M.W = 352.49, triclinic, space group P1, a = 8.467(2) Å, b = 10.228(2) Å, c = 12.249(2) Å; α = 92.595(3)°, β = 104.173(3)°, γ =113.628(3)°; V = 930.0(3) Å3, Z = 2, Dcal = 1.259 Mgm–3, µ = 0.184 mm–1, λ (MoKα)= 0.71073 Å, final R1 and wR2 are 0.0470 and 0.1052, respectively. The piperidine rings adopt chair conformation. The planar phenyl rings are oriented equatorially at 2,6‐positions of the piperidine ring. The molecular packing can be viewed as dimers held together by two N–H…S types of intermolecular hydrogen bonds. Weak C–H…π interactions also support the stability of the molecules in the crystal in addition to van der Waals forces. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)