Structure–pK a correlation via the integrated molecular transform

The integrated molecular transform ( FT m ) is a unitary structure index that has been successfully used for the correlation of 2‐ and 3‐dimensional structure representations with their physicochemical and pharmacological properties. In the present instance the reported pK a values in a series of 30 compounds consisting of five subseries were correlated with their FT m indices. The omission of four outliers gave a moderate correlation across the entire series; within the individual subseries the correlations were considerably improved even with inclusion of the outliers. In general, the logarithmic transform of the pK a did not improve the correlations. This method gives a relatively simple means of estimating pK a in several structure classes. © 1995 John Wiley & Sons, Inc.