2,4,6-TRIS(DIALKYLAMINO)PYRYLIUM SALTS AND RELATED SYSTEMS, SYNTHESIS AND REACTION BEHAVIOUR

Article abstract of DOI:10.1016/S0040-4039(00)80583-3

2,4,6-Tris(dialkylamino)pyrylium salts 9 and 2,6-bis(dialkylamino)-pyran-4-ones 11 as well as their thio-analogues 10, 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 9, 10 undergo electrophilic substitution.They are better represented as polymethine-like systems.The 2,6-bis(dialkylamino)-substituted 11, 12 display a significantly increased donor-reactivity at the carbonyl-oxygen.