Synthetic approach to the construction of unsymmetric pyridyl-1,2,4-triazine complexants.

Efforts toward further closure of the nuclear fuel cycle are contingent, in part, on chemoselective removal of the minor An from Ln within spent nuclear fuel. Liquid-liquid extraction has been demonstrated as an effective vehicle to further irradiate daughter nuclides of the minor An to products with shorter half-lives, lower radiotoxicity, and diminished contribution to heat load. Strategic synthetic methods to evaluate structure-activity relationships of complexants utilized in minor An separations are limited. Traditional, soft-donor complexants of bis-1,2,4-triazinyl-2,6-pyridines (BTPs) reported to date are entirely C2 -symmetric. Disruption of C2 -symmetry was hypothesized to accentuate the solubility of complexants in nonpolar diluents. In this article, a scalable synthetic strategy for the construction of unsymmetric-BTPs is described. Method development, substrate scope, a scale up reaction, and hypothesis-validating solubility data are reported herein. [Display omitted] [ABSTRACT FROM AUTHOR]