
Magnetic Resonance in Chemistry p. 468 - 475 (1991)
Update date:2022-08-03
Topics:
Barraclough, Paul
Firmin, David
Lindon, John C.
Nobbs, Malcolm S.
Sanderson, Paul N.
et al.
The pKa values of six sulmazole analogues were measured spectrophotometrically.The major protonation sites for most of these bridgehead nitrogen heterocycles were determined by 1H and 13C NMR methods.The arylsubstituted imidazo<1,2-a>pyrimidine (4), 8-methoxyimidazo<1,2-a>pyrazine (6), imidazo<1,2-b>pyridazine (9) and imidazo<1,2-b><1,2,4>triazine (11) undergo protonation at the imidazo nitrogen.The imidazo<1,2-a>pyrazine (5) protonates mainly at N-7.In some cases differences in basicity properties between these aryl analogues and the bridgehead heterocycles have been observed.KEY WORDS Polyazaindolizines Protonation 13C NMR 1H NMR pK values
View MoreHubei Lingsheng Pharmaceuticals Co., Ltd.
Contact:+86-0710-3538058
Address:Xiangyang City Xiangcheng Economic Development Zone, Hubei Province
Contact:+86-27-67841589
Address:Add: 999 Gaoxin Road, Donghu New Technology Development Zone, Wuhan City, Hubei, China
Suzhou BEC Fine Chemicals Co., Ltd.
website:http://www.bek.com.cn
Contact:0512-68095917 18913193865
Address:6, Jin Shan Road, Suzhou New District, 215011 China Suzhou Nations Pharmaceutical Innovation Center Inside
Contact:
Address:
Contact:+86-0512-62857507
Address:Boji Science Park, No1688C,Taishan road, Suzhou ,China
Doi:10.1002/ejoc.200500390
(2005)Doi:10.1021/jo00016a014
(1991)Doi:10.1007/BF00476755
(1991)Doi:10.1007/BF00902579
(1966)Doi:10.1002/cmdc.201100288
(2011)Doi:10.1246/cl.2011.1009
(2011)