Abstract: 2, 4, 6-Tris (dialkylamino) pyrylium salts 2 and 2, 6-bis (dialkylamino)-pyran-&ones 11 as well as their thio-analogues l0, 12 have been prepared by a multi-step route starting with 1, 1, 5, 5-tetrachloro-penta-1, 4-dien-3-one (1). The tris (dialkylamino)-substituted 2, $ J undergo electrophilic substitution, They are better represented as polymethine-like systems. The 2, 6_bis (dialkylamino)-substituted ll, at the carbonyl-oxygen. 12 display a significantly ...
