Synthesis, properties and crystal structure of the 2,4-dichlorophenyl- cyanoxime: A powerful carbonyl reductase inhibitor

The compound 2,4-dichlorophenylcyanoxime (later H(2,4-diCl-PhCO)) has significance in its possible application in cancer chemotherapy treatments since it acts as an inhibitor of the human carbonic reductase. This enzyme decreases the effectiveness of anthracycline drug treatment of some types of cancer. The compound was synthesized in high yield at ambient conditions from 2,4-dichlorophenylacetonitrile, using gaseous methylnitrite. The compound was characterized by means of UV-visible, IR, ¹H, ¹³C NMR spectroscopy and X-ray analysis. The cyanoxime crystallizes in a monoclinic space group P2₁/c (#14) with unit cell constants: a = 3.7587(9) Å, b = 30.087(7) Å, c = 7.6874(17) Å, β = 96.163(3); V = 864.3(3) ų, Z = 4. The structure was solved, using direct methods, to final R indices [I > 2σ (I)] R1 = 0.0551 (wR2 = 0.1217). The compound adopts a non-planar, trans-anti configuration with the value of the dihedral angle between the cyanoxime and dichlorophenyl planes equal to 50.61.