Preparation of hexaaza and heptaaza macrocycles functionalized with a single aminoalkyl pendant arm



: Zhang ZB, Mikkola S, Lonnberg H

Publisher: ROYAL SOC CHEMISTRY

: 2003

: Organic and Biomolecular Chemistry

: ORGANIC & BIOMOLECULAR CHEMISTRY

: ORG BIOMOL CHEM

: 1

: 5

: 854

: 858

: 5

: 1477-0520

DOI: https://doi.org/10.1039/b210663a(external)


A practical and reproducible route for the preparation of 1,4,7,10,13,16,19-heptaazacyclohenicosane (1) 1,4,7,10,13,16-hexaazacyclooctadecane (2), and 1,4,7,10,13,17-hexaazacycloicosane (3) bearing a single N-(2-aminoethyl) pendant arm has been developed. Richman-Atkins cyclization in the presence of caesium carbonate was applied to construct the macrocycle from 3-benzoyl-N-1 ,N-5-ditosyl-3-azapentane-1,5-diamine and the appropriate fully N-tosylated N-alpha,N-omega-bis(2-mesyloxyethyl) tri- or tetra-amine. The benzoyl group was selectively removed with potassium tert-butoxide, and the exposed nitrogen atom was reacted with N-tosylaziridine. The tosyl protections were removed with hydrogen bromide in acetic acid, and the product was converted to a free base with the aid of a strong anion exchange resin (OH- form).



Last updated on 2024-26-11 at 12:08