
%0 Journal Article
%A Brown, DJ 
%A Ienaga, K 
%T The Dimroth rearrangement. XVII. The rearrangement of some 1,6-Dihydro-6-imino-1,2-polymethylenepyrimidines into 2,N<sup>6</sup>-polymethylene-bridged 6-aminopyrimidines
%J Australian Journal of Chemistry
%D 1975/01/01
%V 28
%N 1
%P 119-127
%K 
%R https://doi.org/10.1071/CH9750119
%U https://www.publish.csiro.au/paper/CH9750119 
%X The cyclic imino ether, 2-ethoxy-3,4,5,6,7,8-hexahydroazocine (4; n = 6), condenses with amino-methylenemalononitrile (3; R = CN) to give the bicyclic imine, 6,7,8,9,10,11-hexahydro-4-imino-4H-pyrimido[1,2- alazocine-3-carbonitrile (5f), which undergoes Dimroth rearrangement in boiling butanol to yield a &#946;-bridged isomer, 2,10,13- triazabicyclo[7,3,1]trideca-1(13),9,11-triene-12-carbo-nitrile (7a). Imino ethers (4) with fewer than six methylene groups give bicyclic imines which are incapable of rearrangement; those with more than six methylene groups give imines which cannot be isolated on account of their extremely facile rearrangement into &#946;-bridged isomers. Ionization constants and the ultraviolet, infrared, proton magnetic resonance and mass spectra of the main products are discussed. 
