Metronidazole (443-48-1) 's Synthetic route

SYNTHESIS OF METRONIDAZOLE FROM ETHYLENEDIAMINE

Kraft, M. Ya.  Kochergin, P. M.  Tsyganova, A. M.  Shlikhunova, V. S.

Alkali Metal, Chlorine and other Promoters in the Silver-catalysed Selective Oxidation of Ethylene

Grant, Robert B.  Harbach, Christopher A. J.  Lambert, Richard M.  Tan, S. Aun

Ethylene oxidation over well characterised Ag(111) surfaces has been investigated by temperature-programmed reaction measurements and by differential batch reactor studies at pressures up to 50 Torr.The influence of chlorine predosing on catalytic activity indicates that a chemisorbed atomic oxygen species is responsible for both partial oxidation and complete oxidation to CO2 + H2O.This tends to be confirmed by experiments using N2O as the oxidant, both with the single crystal specimen and with a practical Ag-αAl2O3 catalyst in a flow microreactor.Dissolved oxygen, like adsorbed chlorine, is found to be a selectivity promoter.Adsorbed Cs also increases the rate of ethylene oxide production but can also positively influence the overall activity of the system.The results suggest that chlorine and dissloved oxygen promoters principally affect the primary chemistry, whereas the main effect of Cs is on the secondary chemistry (further oxidation of ethylene oxide).This view tends to be confirmed by temperature-programmed reaction measurements and by direct experiments on the influence of Cl and Cs on the isomerisation and combustion of ethylene oxide itself.It is suggested that these effects are primarily electronic in origin and a mechanism based on this view is presented.In the presence of Cs, both CO2 and NO_x can act as selectivity promoters for the formation of ethylene oxide.