Quaternization of 2-(arylamino)aryliminophosphoranes. A route to N,N'-disubstituted 2-aminodiarylamines and unsymmetrically substituted 1-aryl-1,2,5,6-tetrahydro-1,6-benzodiazocines
摘要:
A convenient route leading to variously substituted N-alkyl-N'-aryl-o-phenylenediamine derivatives via quaternization of the imine nitrogen atom of 2-(arylamino)aryliminophosphoranes is presented. The method allows to introduce identical or different alkyl groups onto both nitrogen atoms. The N, N'-bis-allyl derivatives so obtained, after protecting the secondary amine group, easily undergo RCM cyclization providing unsymmetrically substituted 1,2,5,6-tetrahydro-1,6-benzodiazocine systems in high yields.