Synthesis and characterization of 7,16-bis(phenylazo)tetraaza[14]annulenes

Citation
K. Sakata et al., Synthesis and characterization of 7,16-bis(phenylazo)tetraaza[14]annulenes, J HETERO CH, 38(4), 2001, pp. 933-938
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
JOURNAL OF HETEROCYCLIC CHEMISTRY
ISSN journal
0022-152X → ACNP
Volume
38
Issue
4
Year of publication
2001
Pages
933 - 938
Database
ISI
SICI code
0022-152X(200107/08)38:4<933:SACO7>2.0.ZU;2-G
Abstract
The diazo coupling reaction between a tetraaza[14]annulene (1) and a series of 4-substituted phenyldiazonium tetrafluoroborates yielded the correspond ing 7,16-disubstituted products. Mass spectra indicate the presence of mole cular ion peaks that substantiate the 7,16-disubstituted products (4); the lack of olefinic proton signals corresponding to the 7,16- position in the H-1 nmr spectra of 4 also show that diazo coupling has taken place. Analysi s of signals corresponding to the methyl groups of 4 in their H-1 and C-13 nmr spectra indicate that the imine-bis-hydrazone form is present for compo unds that do not contain p-methoxyphenyl groups. However, analysis of methy l signals in the nmr specta of compounds 4 containing p-methoxyphenyl group s show that the bis-azo form and the imine-bis-hydrazone form are present t hrough tautomerism. Complexation with nickel(II) ion induces the formation of the bis- azo structure.