Pratibha Sharma, Ashok Kumar, Shikha Sharma
Nov 1, 2004
Citations
0
Influential Citations
2
Citations
Journal
ChemInform
Abstract
Present communication deals with the synthesis and electrochemical reduction of 1-dichlorophosphino-2-phospha-3-phenyl-4-mercapto-5-aza-6-hydroxy-7-arylazoindolizines 4a-1.Initially 6-hydroxy- 2-mercapto - 4 - methyl -5 -arylazopyrimidine was synthesized as precursor and which in turn was treated with benzyl chloride and phosphorus trichloride under strong alkaline conditions to obtain the title indolizines. Furthermore their purity has been ascertained by TLC resolution studies (xylene-ethylacetoacetate, 7:3). Structure of all the synthesized compounds have been established on the basis of their consistent elemental, IR and NMR spectral data. The comprehensive study of electrochemical behaviour of all the synthesized compounds has been studied over a wide pH range. It gives diffusion-controlled, irreversible and single two-electron wave corresponding to the reduction of -N=N- moiety. On the basis of d.c. polarography and cyclic voltammetry, a reaction mechanism is suggested. The kinetic parameters i.e., charge transfer coefficient (an) and forward rate constant (k o f , h ) have been calculated. The effect of ionic strength has also been studied. A plausible mechanism has also been suggested on the basis of number of protons involved in the rate determining step and number of electrons involved in the reduction.