Unusual ring expansion observed during the Dakin–West reaction of tetrahydroisoquinoline-1-carboxylic acids using trifluoroacetic anhydride: an expedient synthesis of 3-benzazepine derivatives bearing a trifluoromethyl group

1992 ◽  
Vol 0 (15) ◽  
pp. 1076-1077 ◽  
Author(s):  
Masami Kawase
Keyword(s):  
Carboxylic Acids ◽  
Ring Expansion ◽  
Trifluoroacetic Anhydride ◽  
Trifluoromethyl Group

Some Derivatives of 1-Benzazepine. Part II

1974 ◽  
Vol 52 (4) ◽  
pp. 610-615 ◽  
Author(s):  
G. R. Birchall ◽  
A. H. Rees
Keyword(s):  
Carboxylic Acids ◽  
Ring Expansion ◽  
Hydrazoic Acid ◽  
Ring Contraction ◽  
Effect Of Substituents ◽  
Ring Expansion Reaction ◽  
Derivatives Of

We have investigated the ring expansion of some substituted 1,4-naphthoquinones by hydrazoic acid to yield new 1-benzazepine derivatives of the "azatropolone" type. Ring contraction of those products, which are 2,5-dihydro-3-hydroxy-2,5-dioxo-1-benzazepines, gives 4-quinolone-2-carboxylic acids. Some of the reactions of the new benzazepine system were investigated. Attempts to prepare substituted derivatives suitable for making 1-benzazatrop-5-one were not successful.The effect of substituents on the ring expansion reaction is discussed and an anomalous ring expansion to a 2,5-dihydro-4-hydroxy-2,5-dioxo-1-benzazepine is described and explained mechanistically.

ChemInform Abstract: Ruthenium-Catalyzed Regio- and Stereoselective Addition of Carboxylic Acids to Aryl and Trifluoromethyl Group Substituted Unsymmetrical Internal Alkynes.

ChemInform ◽  
2011 ◽  
Vol 42 (39) ◽  
pp. no-no
Author(s):  
Motoi Kawatsura ◽  
Junya Namioka ◽  
Koji Kajita ◽  
Mitsuaki Yamamoto ◽  
Hiroaki Tsuji ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Trifluoromethyl Group ◽  
Stereoselective Addition ◽  
Internal Alkynes

scholarly journals Synthesis of 2,2'-Dipyrryl Ketones from Pyrrole-2-carboxylic Acids with Trifluoroacetic Anhydride

2013 ◽  
Vol 34 (9) ◽  
pp. 2604-2608 ◽  
Author(s):  
Se Hee Kim ◽  
Jin Woo Lim ◽  
Jin Yu ◽  
Jae Nyoung Kim
Keyword(s):  
Carboxylic Acids ◽  
Trifluoroacetic Anhydride

Synthesis of Tetracyclic Fused Quinolines via a Friedel–Crafts and Beckmann Ring Expansion Sequence

2019 ◽  
Vol 72 (12) ◽  
pp. 945
Author(s):  
Hassan A. K. Abd El-Aal ◽  
Talaat I. El-Emary
Keyword(s):  
Carboxylic Acids ◽  
Ring Expansion ◽  
Molecular Scaffolds ◽  
Elemental Analyses ◽  
Key Steps

An efficient protocol for the construction of tetracyclic fused quinolines (pyrazole-fused azepino-, azocino-, and azonino[3,2-b]quinolinones) via consecutive Friedel–Crafts and Beckmann reactions has been developed. The key steps in the syntheses of these new molecular scaffolds involve acid-mediated cyclization of 2-(pyrazol-3-yl)quinoline based carboxylic acids 6a–c, 8, and 12 to ketones 13a–e, followed by Beckmann rearrangements of the corresponding oximes 14a–e to provide the tetracyclic-fused quinoline skeletons 15a–e. Structures of synthesised compounds without stereochemical implication were confirmed by NMR and elemental analyses.

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