COLORIMETRIC DETERMINATION OF PHENOTHIAZINE DRUGS. 4- CORRELATION BETWEEN MOLAR ABSORPTIVITY AND F, R AND X PARAMETERS OF RING SUBSTITUENTS

Document Type : Original Article

Authors

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Assiut, Assiut, Egypt

Abstract

Colorimetric determination of phenothiazines with NBS in strong sulfuric acid solution has been previously reported (6, 7). Correlation of log emax with  and 2cv parameters of C-2 and N-10 substituents is highly significant only on absence of vulnerable groups at C-2 position. Log emax of four compounds with the same N-10 side chain was correlated with Á parameters of C-2 substituents irrespective of their vulnerability to the reagents. Correlation equations were used to predict the electronic parameters Á, and sp of –SO2N(CH3)2 from the spectrophotometric reaction model.