New phosphoramidic acid derivatives were synthesized by three different methods in the liquid-liquid and liquid-solid systems. The highest yields were obtained when the liquid-solid system was used. Moreover, for these compounds, the retention factor was predicted, using a robust model obtained for a set of phosphoramidic acid derivatives, which were previously synthesized in our laboratory. For these compounds, the retention factor (k ) was determined by means of the high performance liquid chromatography technique, using a Nucleosil C18 column as a stationary phase and methanol as a mobile phase. The stepwise multiple linear regression (MLR) and partial least square (PLS) methodology were used to investigate the correlation between the retention factor and a number of molecular descriptors for the mentioned compounds. In both procedures, a considerably large number of molecular descriptors have been used. The statistical qualities of MLR and PLS equations have been assessed on the basis of several parameters such as squares of the correlation coefficient (R 2 = 0.985), standard error of estimate (SEE = 0.149), Fischer test (F = 257.528), and the cumulative sum of squares of the correlation coefficient R 2 Y(CUM) = 0.984, the cu-Correspondence to: Luminita Crisan; mulative fraction of the total variation of the Y values that can be predicted for all the extracted principal components by cross-validation Q 2 (CUM) = 0.971, respectively, and by the Y-randomization test. The MLR and PLS equations can be useful for the estimation and comparison of the retention factor, for new synthesized phosphoramidic acid derivatives, using the selected molecular descriptors. C 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:138-145, 2013; View this article online at wileyonlinelibrary.com.