Tetrahedron Letters p. 333 - 336 (2016)
Update date:2022-08-31
Topics:
Mastalir, Matthias
Pittenauer, Ernst
Allmaier, Günter
Kirchner, Karl
A series of ring substituted pyridines were selected for the sodium amide initiated heterogeneous Chichibabin amination to obtain 2,6-diaminopyridine derivatives which are important synthons for the preparation of PNP pincer ligands. The substrates were treated with an excess of sodium amide in neat mineral oil as solvent under an argon atmosphere. The reaction required temperatures of up to 215°C under vigorous stirring with an overall reaction time of 3-5 h. In the case of methyl, tert-butyl, phenyl, pyridinyl, and hydroxyl substituted pyridines the desired products were obtained in good to excellent yields (63-96%). Thus, the Chichibabin reaction provides an inexpensive and economic alternative to methodologies starting from halopyridines or pyridine N-oxides provided that the substituents are inert under the harsh reaction conditions.
View MoreContact:+86-0512-62857507
Address:Boji Science Park, No1688C,Taishan road, Suzhou ,China
Hangzhou Dawn Ray Pharmaceutical Co.,Ltd
website:http://www.dawnraypharma.com/
Contact:+86-571-85335020
Address:1018 Guangyin Building,No.42 E.Fengqi Road,Hangzhou,310012 China
Xinji City Taida Sinopec Co., Ltd.
Contact:0086-311-85341278
Address:No.6, Nanhua Road,Xinji City Road,Hebei Province,China
Shanghai doly chemical Co.,Ltd
Contact:+86-21-34716221
Address:No.328,WuHe Roard,MinHang,ShangHai China
Huzhou City Linghu Xinwang Chemical Co.,Ltd.
Contact:86-572-3948695/3945236
Address:huzhou
Doi:10.1002/asia.201300500
(2013)Doi:10.1246/cl.2005.180
(2005)Doi:10.1016/j.saa.2015.12.024
(2016)Doi:10.1139/v99-123
(1999)Doi:10.1021/ja01857a018
(1941)Doi:10.1021/ja0541940
(2005)