PK(A), LOG P-OCT AND HPLC CAPACITY FACTOR ON A POROUS POLYMER GEL IN THE STUDY OF A SERIES OF 2-BENZAMIDO-5-NITROTHIAZOLES

Partitioning of 15 derivatives of 2-benzamido-5-nitrothiazole between octanol and Tris/HCl buffers yields values for acidity constant in wat er (K-a), partition coefficient (P-oct), extraction constant of base-c ation ion-pair (K-e). pK(a)'s have also been measured by spectrophotom etric titration in an acetonitrile/water (10:90 v/v) solvent mixture. Lipophilicity has also been determined using HPLC on a styrene/divinyl benzene polymeric stationary phase in methanol/water and acetonitrile/ water media. Correlations between log P-oct and HPLC capacity factor l og k' are established. On the basis of our results, the fragmental con tribution of the benzamide moiety in the CLOGP program could be correc ted.