Gas-phase pyrolysis in organic synthesis: A route for synthesis of cyanamides

Article abstract of DOI:10.1002/jhet.217

(Chemical Equation Presented) Pyrolysis of 1,7-di-[(E)-1- morpholinomethylidene]- and 1,7-di-[(E)-1-piperidino-methylidene]-4,6,10,12- tetramethylamino-2,8-dioxo-1,7-diaza-3,5,9,11-cyclododecatetraene-3, 9-dicarbonitrile 6a,b afforded pyridone 10 in addition to cyanamides 11a,b. On the other hand, pyrolysis of 1-[E-(4-(E-3-cyano-4,6-dimethyl-2-oxopyridin-1(2H)- ylimino) methylpiperazin-1-yl] methylenamino-4,6-dimethyl-2-oxo-1,2- dihydropyridine-3-carbonitrile 8 gave 1-amino-4,6-dimethyl-2-oxo-1,2- dihydropyridine-3-carbonitrile 13 as well as piperazine. The mechanism of pyrolysis and the effect of stereochemistry of pyrolyzed substrates on the nature of the pyrolysates are discussed.