Convenient preparation of 3,6-dialkyl-1,6-dihydro-s-tetrazines

1,6-Dihydro-s-tetrazines such as 1, with a large variety of substituents in the 3- and 6-position of the heterocycle, have been synthesized, and due to their homoaromaticities and their potential reactivities, have aroused more and more interests (Sauer, J. 1,2,4,5-Tetrazines. In Comprehensive Heterocyclic Chemistry 11, Boultou, A.J., Ed.; Elsevier: Oxford, UK, 1996; Vol. 6, 901; Neunhoeffer, H. In Comprehensive Heterocyclic Chemistry 1, Katritzky, A., Ed.; Pergamon Press Ltd.: Federal Republic of Germany, 1984; Vol. 3, 545).