One-Step Cyclization:
Synthesis of <i>N</i>‑Heteroalkyl‑<i>N</i>′‑tosylpiperazines
- Publication date
- Publisher
Abstract
Piperazine derivatives are important intermediates in
organic synthesis and useful building blocks in pharmaceutical and
fine chemical industries. Currently available synthetic routes for
these heterocyclic compounds have limited scope owing to the harsh
reaction conditions, low yields, and multistep process. Herein, we
reported a practical method for synthesis of alkyl-, alcohol-, amine-,
and ester-extended tosylpiperazines under mild conditions with moderate
to high yields. This protocol exhibits potential applicability in
the synthesis of pharmaceuticals and natural products because of the
operational simplicity and the conveniently available reactants. On
the basis of the experimental and theoretical results, a plausible
mechanism of aliphatic nucleophilic substitution (S<sub>N</sub>) in
the cyclization has been postulated and evidence for the formation
of a six-membered ring has also been confirmed by means of density
functional theory (DFT) calculations