Synthesis of N,N'-dimethyl diazacoronands via double-quaternization reaction

Article abstract of DOI:10.1016/S0040-4020(01)90199-1

α,ω-Tertiary diamines react under high pressure with α,ω-di-lodo compounds to give the cyclic bis-quaternary salts in almost quantitative yields. It is also shown that the same reaction can be carried out under atmospheric-pressure conditions with slightly lower yields. Subsequent demethylation of the bis-quaternary salts with triphenylphosphine affords N,N'-dimethyl diazcoronands in high yield.