- A new application of diphenylphosphorylazide (DPPA) reagent: Convenient transformations of quinolin-4-one, pyridin-4-one and quinazolin-4-one derivatives into the 4-azido and 4-amino counterparts
-
Herein, we describe a transformation of the oxo-function of a series of quinolin/pyridin/quinazolin-4-ones into 4-azido and thence into 4-amino derivatives in moderate yields by a very short and convenient new procedure using DPPA (diphenylphosphoryl azide) as reagent. A mechanism for this interesting new application of DPPA is suggested based on the identification of some of the intermediates.
- Aizikovich, Alexander,Kuznetsov, Vladimir,Gorohovsky, Sofia,Levy, Amalia,Meir, Simha,Byk, Gerardo,Gellerman, Garry
-
-
Read Online
- Chemistry of Thienopyridines. XXXIII. Synthetic Routes to 5- and 7-Substituted Thienopyridines from the N-Oxide
-
Thienopyridine (1) is oxidized to N-oxide 1a by means of m-chloroperoxybenzoic acid (83percent).Compound 1a forms adducts with hydrogen chloride and picric acid and gives ring substitution alpha or gamma to the heteronitrogen atom.Thus, 1a plus nitric and sulfuric acids produces the 7-nitro-N-oxide 1m (63percent), or plus phosphorus oxychloride gives a mixture of 5-chloro and 7-chloro (1j) derivatives of 1.Compound 1m is convertible into a variety of other derivatives of 1, viz 7-chloro-N-oxide, 1j, 7-bromo-N-oxide, 7-nitro and 7-amino. 5-Cyano-1, formed from 1a, is, in turn, transformed into a methyl imidate (93percent), cyclic amidines, and a 5-tetrazolyl-1 (91percent).These results confirm the prediction that 1a, thienopyridine-4-oxide and quinoline 1-oxide should exhibit closely similar (i.e. analogous) chemical reactions.
- Klemm, L. H.,Louris, John N.,Boisvert, William,Higgins, Clay,Muchiri, Daniel R.
-
p. 1249 - 1252
(2007/10/02)
-