Efficient Preparation of Pyridinyl-1,2,4-Triazines via Telescoped Condensation with Diversely Functionalized 1,2-Dicarbonyls

Article abstract of DOI:10.1002/jhet.2374

The development of materials for efficient chemoselective extraction of minor actinides remains at the forefront of research efforts in the area of separation science. Lewis basic complexants derived from nitrogen-donor scaffolds are often employed in this area due to favorable complexation with the transuranic element americium. In the present work an efficient procedure for the preparation of eight useful 3-pyridin-2-yl-1,2,4-triazines (2 novel) is demonstrated via telescoped condensation with the requisite 1,2-dicarbonyl in two-pots without additives, differentially extractive work-up procedures, or recrystallization. Additional efforts in this area have demonstrated the utility of polar aprotic solvents for the preparation of nine functionalized pyridinyl-2,6-bis-1,2,4-triazines (4 novel) directly from the requisite 2,6-pyridine dicarbonitrile in 49–99% yield over four total steps. The streamlined preparation of these important materials and detailed synthetic procedures is reported herein.