1682-20-8Relevant articles and documents
Studies on the synthesis of fluorinated Schiff bases; biological activity of resulting (E)-N-benzylidene-2,3,5,6-tetrafluoropyridin-4-amine and 4-amino-2-ethoxy-3,5,6-trifluoropyridine
Raache, Imane,Sekhri, Lakhdar,Tabchouche, Ahmed
, p. 1799 - 1813 (2016)
The present work is aimed mainly to synthesize new fluorinated compounds and their biological significance against tested bacteria and fungus. Thus, the 4-amino-2-ethoxy-3,5,6-trifluoropyridine 4 was synthesized by the reaction of 4-amino 2,3,5,6-tetraflu
MECHANISM FOR REACTIONS OF HALOGENATED COMPOUNDS. PART 4. ACTIVATING INFLUENCES OF RING-NITROGEN AND TRIFLUOROMETHYL IN NUCLEOPHILIC AROMATIC SUBSTITUTION
Chambers, R. D.,Martin, P. A.,Waterhouse, J. S.,Williams, D. L. H.,Anderson, B.
, p. 507 - 514 (1982)
Rate constants have been measured for the reactions of ammonia with various fluorinated pyridines and diazines in aqueous dioxan at 25 deg C.From the results the activating effects of ring-nitrogen (relative to C-H) and of trifluoromethyl (relative to -H)
Reactions of polyfluoropyridines with bidentate nucleophiles: Attempts to prepare deazapurine analogues
Coe, Paul L.,Rees, Anthony J.,Whittaker, Jane
, p. 13 - 22 (2001)
Reactions of pentafluoropyridine with guanidine, thiourea and urea with the hope of preparing derivatives which may be cyclised to polyfluorodeazapurines are described The reactions with urea and thiourea produced, somewhat unexpectedly, bis-(2,3,5,6-tetrafluoro-4-pyridyl)amine and bis-(2,3,5,6-tetrafluoro-4-pyridyl)sulfide, respectively, the structure of the amine was confirmed by X-ray crystallography. The product from the guanidine reaction was the expected 4-substituted tetrafluoropyridine derivative. Attempts to cyclise the latter are described and a rationalisation to explain the unexpected melamine derivatives which were produced is given.
STUDIES IN AZIDE CHEMISTRY. PART 12. ONE-POT CONVERSION OF 4-AZIDOTETRAFLUOROPYRIDINE TO 1,3,4-TRIFLUORO-7,9-DIMETHYL-11H-PYRIDOBENZODIAZEPINE
Banks, Ronald E.,Madany, Ismail M.
, p. 357 - 360 (1985)
Thermolysis of 4-azidotetrafluoropyridine in the presence of an excess of mesidine at 170 deg C yields tetrafluoro-4-(2,4,6-trimethylphenylazo)-pyridine, which undergoes intramolecular dehydrofluorination in situ to provide 1,3,4-trifluoro-7,9-dimethyl-11H-pyridobenzodiazepine.
Reductive defluorination of polyfluoroarenes by zinc in aqueous ammonia
Laev, Sergey S.,Shteingarts, Vitalij D.
, p. 3765 - 3768 (1997)
Aqueous ammonia has been found to be a good and versatile medium for the reductive defluorination of polyfluoroarenes by zinc. Upon the reduction of pentafluorobenzoic acid, 2,3,4,5,6-pentafluorobenzyl alcohol, pentafluoropyridine and heptafluoro-2-naphthoic acid individual products derived from the removal of one fluorine atom have been obtained.
N-Halogeno compounds. Part 16. Perfluoro-[N-fluoro-N-(4-pyridyl)acetamide] - A new site-selective electrophilic fluorinating agent
Banks,Besheesh,Tsiliopoulos
, p. 39 - 42 (1996)
Perfluoro-[N-fluoro-N-(4-pyridyl)acetamide] (2), prepared via direct fluorination of the sodium salt (4) of perfluoro-[N-(4-pyridyl)-acetamide], readily fluorinates diethyl sodio(phenyl)malonate [→PhCF(CO2Et)2], 1-morpholinocyclohexene(→2-fluorocyclohexanone), anisole (→2-and 4-FC6H4OMe), and phenol (→2-and 4-FC6H4OH) under mild conditions. The sodium salt precursor (4) of this side-chain N-F reagent (2) is easily made from pentafluoropyridine via the trifluoroacetylation of its 4-amino derivative or, more directly, by treating it with two equivalents of the monosodium salt of trifluoroacetamide.
Hydrogen Bond Directed Photocatalytic Hydrodefluorination: Overcoming Electronic Control
Khaled, Mohammad B.,El Mokadem, Roukaya K.,Weaver, Jimmie D.
supporting information, p. 13092 - 13101 (2017/09/26)
The photocatalytic C-F functionalization of highly fluorinated arenes is a powerful method for accessing functionalized multifluorinated arenes. The decisive step in the determining regioselectivity in fluorine functionalization is fluoride fragmentation from the radical anion of the multifluorinated arene. To date, the availability of regioisomers has been dictated by the innate electronics of the fluorinated arene, limiting the synthetic utility of the chemistry. This study investigates the remarkable ability of a strategically located hydrogen bond to transcend the normal regioselectivity of the C-F functionalization event. A significant rate acceleration is additionally observed for hydrodefluorination of fluorines that can undergo intramolecular hydrogen bonds that form 5-8-membered cycles with moderately acidic N-H's. The hydrogen bond is expected to facilitate the fragmentation not only by bending the C-F bond of the radical anion out of planarity but also by increasing the exothermicity of the fluoride extrusion step through protonation of the naked fluoride. Finally, the synthetic utility of the method is demonstrated in an expedited synthesis of the trifluorinated α-phenyl acetic acid derivative required for the commercial synthesis of Januvia, an antidiabetic drug. This represents the first synthesis of a commercially important multifluorinated arene via a defluorination strategy and is significantly shorter than the current strategy.
Radical ipso-substitution of a carbon-fluorine bond leading to fluoro-7-azaindolines and fluoro-7-azaindoles
Liu, Zhibo,Qin, Ling,Zard, Samir Z.
supporting information, p. 2704 - 2707 (2014/06/09)
Rare examples of a synthetically useful radical ipso-substitution of a carbon-fluorine bond are reported, leading to highly functionalized 5,6-difluoro-7-azaindolines. An unexpected hydrogen atom translocation and fragmentation with loss of molecular nitrogen and formation of a nitrile were observed in the case of an N-benzyl-tetrazole derivative.
Photocatalytic hydrodefluorination: Facile access to partially fluorinated aromatics
Senaweera, Sameera M.,Singh, Anuradha,Weaver, Jimmie D.
supporting information, p. 3002 - 3005 (2014/03/21)
Polyfluorinated aromatics are essential to materials science as well as the pharmaceutical and agrochemical industries and yet are often difficult to access. This Communication describes a photocatalytic hydrodefluorination approach which begins with easily accessible perfluoroarenes and selectively reduces the C-F bonds. The method allows facile access to a number of partially fluorinated arenes and takes place with unprecedented catalytic activity using a safe and inexpensive amine as the reductant.
Imidazopyridine and pyrimidinopyridine systems from perfluorinated pyridine derivatives
Cartwright, Matthew W.,Sandford, Graham,Bousbaa, Jamaal,Yufit, Dmitrii S.,Howard, Judith A.K.,Christopher, John A.,Miller, David D.
, p. 7027 - 7035 (2008/02/05)
Annelation of pentafluoropyridine via an intramolecular nucleophilic aromatic substitution process with benzamidine gave an imidazopyridine system in high yield in a two step process whilst alkyl amidines gave 4-aminotetrafluoropyridine by a competing eli
