Efficient synthetic routes for the preparation of azetidine starting from commercially available 3‐amino‐l‐propanol or 3‐halopropylamine hydrohalides are reported. First, the appropriate N‐trityl‐ or N‐dimethoxy‐trityl protected tosyloxy‐ or halopropylamines were prepared. These precursors were then cyclized into the N‐trityl‐ or N‐dimethoxytritylazetidines. The N‐protecting groups were removed in the presence of perchloric acid giving the hydrogen perchlorate salt of azetidine. The latter compound was transformed into its free base using a strong base under anhydrous conditions. The relatively expensive 4,4′‐dimethoxytrityl chloride and less expensive trityl chloride used in these synthetic procedures were recycled in good yields. Azetidine hydrogenperchlorate can be used to prepare N‐substituted azetidines without the need to isolate the free azetidine.
ASJC Scopus subject areas
- Organic Chemistry