A series of thioether profragrances was prepared by reaction of different sulfanylalkanoates with δ-damascone and tested for their release efficiencies in a fabric-softener and an all-purpose cleaner application. Dynamic headspace analysis on dry cotton and on a ceramic plate revealed that the performance of the different precursors depended on the structure, but also on the particular conditions encountered in different applications. Moreover, profragrances derived from other α,β-unsaturated fragrance aldehydes and ketones were synthesized analogously and evaluated using the same test protocol. Thioethers were found to be suitable precursors to release the corresponding fragrances, but neither the quantity of profragrance deposited from an aqueous environment onto the target surface, nor the amount of fragrance released after deposition could be linearly correlated to the hydrophilicity or hydrophobicity of the compounds. Different sets of compounds were found to be the best performers for different types of applications. Only one of the compounds evaluated in the present work, namely the thiolactic acid derivative of δ-damascone, efficiently released the corresponding fragrance in both of the tested applications. Profragrance development for functional perfumery thus remains a partially empirical endeavour. More knowledge (and control) of the various application conditions are required for an efficient profragrance design.

The n‐octanol/water partition coefficient (LogP) of a chemical substance is a key parameter for assessing its potential (eco)‐toxicological effects and environmental fate. To measure the LogP of properfume Haloscent®D (expected LogP > 9), no direct measurement technique can be applied and the reliability of in silico models is impaired by the absence of robust datasets in the high LogP range. Indirect method using reversed‐phase‐HPLC (RP‐HPLC) is promising but we demonstrate that the lack of suitable standards lead to significant discrepancy and poor accuracy. Extrapolation of the correlation between the RP‐HPLC retention factor (logk) of low‐carbon chain homologues and their LogP measured by slow‐stir method has been studied. To select the most suitable standards, the impact of specific moiety representative of Haloscent®D (linear alkyl chain, delta‐damascone moiety, thioether function) on the logk vs. estimated LogP has been checked on different molecules and it was demonstrated that the alkyl chain had the most impact on this correlation. The stability in the molecular conformation of Haloscent®D homologue series was also verified to ensure that no folding occurred as from a certain alkyl chain length, and that consequently extrapolation is feasible up to Haloscent®D. Accuracy of the extrapolated LogP value was calculated from the prediction interval of the logk vs. LogP regression. The LogP of the Haloscent®D was concluded to be 9.7 ± 0.5. Copyright © 2016 John Wiley & Sons, Ltd.

No abstract