Selective Protection of the Primary Amine Functions of Linear Tetraamines Using the Trityl Group

Abstract

Treatment of linear tetraamines 3,6-diaza-1,8-octanediamine (1); 4,7-diaza-1,10-decanediamine (2); and 4,9-diaza-1,12-dodecanediamine (spermine) (3) with equimolar amounts of trityl chloride allowed preparation of the α,ω-bistrityl-protected tetraamines 4, 6 and 8 in good to excellent yields. A 2:1 ratio of trityl chloride to tetraamine gave a tritrityl-substituted by-product. An internal N,N'-ditrityl-substituted tetraamine, 5,8-ditrityl-1,5,8,12-tetraazadodecane (10), was also prepared as a further proof of the structures of the α,ω-ditrityl-substituted tetraamines.