Construction of 2,3,4,5-tetrahydro-1,2,4-triazines via [4 + 2] cycloaddition of α-halogeno hydrazones to iminesElectronic supplementary information (ESI) available: Copies of NMR spectra for all products related to this article; X-ray single crystal structure analysis data for 3aa. CCDC 1508810. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6ra27767e

In the presence of sodium carbonate, the [4 + 2] cycloaddition of α-halogeno hydrazones to imines proceeded readily, and furnished 2,3,4,5-tetrahydro-1,2,4-triazines in moderate to high chemical yields. In the presence of sodium carbonate, the [4 + 2] cycloaddition of α-halogeno hydrazones to imines proceeded readily, and furnished 2,3,4,5-tetrahydro-1,2,4-triazines in moderate to high chemical yields.