OLD REAGENTS, NEW RESULTS - AROMATIZATION OF HANTZSCH 1,4-DIHYDROPYRIDINES WITH MANGANESE-DIOXIDE AND 2,3-DICHLORO-5,6-DICYANO-1,4-BENZOQUINONE

Authors
EYNDE JJV DELFOSSE F MAYENCE A VANHAVERBEKE Y
Citation
Jjv. Eynde et al., OLD REAGENTS, NEW RESULTS - AROMATIZATION OF HANTZSCH 1,4-DIHYDROPYRIDINES WITH MANGANESE-DIOXIDE AND 2,3-DICHLORO-5,6-DICYANO-1,4-BENZOQUINONE, Tetrahedron, 51(23), 1995, pp. 6511-6516
Citations number
43
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron → ACNP
ISSN journal
00404020
Volume
51
Issue
23
Year of publication
1995
Pages
6511 - 6516
Database
ISI
SICI code
0040-4020(1995)51:23<6511:ORNR-A>2.0.ZU;2-U
Abstract
Hantzsch 1,4-dihydropyridines are readily oxidized by manganese dioxid e or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in dichloromethan e at room temperature. With manganese dioxide loss of the 4-substituen t, in addition to aromatization, occurs when it is a secondary alkyl o r a benzylic group and sonication significantly reduces the reaction t imes. In contrast, loss of the 4-substituent is never observed when DD Q is the oxidative species.