Reagent for synthesis of secondary amines by two consecutive N-alkylations and its application to orthogonally protected spermidine

A novel reagent, tert-butyl 2-naphthalenesulfonylcarbamate, has been designed to allow the stepwise synthesis of secondary aliphatic amines by two consecutive N-alkylations with intermediate Boc-cleavage and final desulfonylation under mild and experimentally convenient conditions. Its application was demonstrated to make an orthogonally protected spermidine derivative, suitable for further selective modification. Each individual step, including the final cleavage of 2-naphthalenesulfonyl to provide the secondary amine nitrogen, took place in high yield.