Some nucleophilic substitutions in 2‐cyano‐3‐nitroimidazo[1,2‐<i>a</i>]pyridine

Arias, Ladislao; Salgado-Zamora, Héctor; Campos, Elena; Reyes, Adelfo; Cervantes, Humberto; Taylor, Edward C.

doi:10.1002/jhet.5570430307

Cited by 15 publications

(2 citation statements)

References 17 publications

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“…48 Studies of the substitution patterns in 2-cyano-3-nitroimidazole[1,2a]pyridine have shown that nitrogen and oxygen nucleophiles substitute the 2-cyano group whereas sulfur nucleophiles replace the 3-nitro group. 49 4,5-Dicyanopyridazine may react with pyrrole and indole systems as a heterocyclic azadiene in IEDDA Diels-Alder reactions. However, in acetic acid as solvent reaction occurs by substitution of CN at the 4-position and intermediates such as (10) may be isolated.…”

Section: Heterocyclic Systemsmentioning

confidence: 99%

Nucleophilic Aromatic Substitution

Crampton

2010

Organic Reaction Mechanisms · 2006

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There has been a study of the dediazoniation of 4-nitrobenzenediazonium ions in methanol-water mixtures under acidic conditions using kinetic, spectrophotometric, and chromatographic methods. Two decomposition routes were identified: an ionic pathway yielding nitrophenol and nitroanisole, and a radical pathway involving transient diazo ethers which undergo homolytic fragmentation giving nitrobenzene or 4,4 -dinitrobiphenyl. 1 Catalysis by the Cu(I)-Cu(II)-1,10-phenanthroline system has been reported in the reaction of arenediazonium salts with potassium thiocyanate to yield aryl thiocyanates. 2 Bis(trifluoromethanesulfonyl)amide anions (Tf 2 N − ) are usually considered to have very low nucleophilic reactivity. However, in imidazolium ionic liquids this anion has been shown to have higher reactivity than bromide ions in heterolytic dediazoniation reactions. 3 It has been shown that displacement of the iodo substituent in 4-iodo-1,1,2,2,9,9,10, 10-octafluoro[2.2]paracyclophane by arenethiolates or by stabilized enolates occurs by the radical chain S RN 1 mechanism. The reaction occurs in DMF with photochemical stimulation. 4 The S N Ar MechanismThere has been a review of relationships between activation parameters and mechanisms for biomolecular reactions in solution, including both nucleophilic substitutions and additions. 5 Several studies have been reported involving substitutions by amine nucleophiles where both electronic and steric effects may be important. Kinetic studies of the reactions of 2,4-dinitrophenyl 2,4,6-trinitrophenyl ether (1) with ring-substituted 175

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Section: Heterocyclic Systemsmentioning

confidence: 99%

Nucleophilic Aromatic Substitution

Crampton

2010

Organic Reaction Mechanisms · 2006

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“…Another protocol involves the reaction of cyanamides with pyridinium salts, preliminarily obtained by microwave activation from 2‐chloropyridines and compounds containing a halomethylene group . Finally, aminoimidazo[1,2‐ a ]pyridines can be synthesized by substitution of the nitrile group with amino function in the corresponding cyanosubstituted derivatives, reduction of the nitro group in nitroimidazo[1,2‐ a ]pyridines, or direct amination of 3‐nitroimidazo[1,2‐ a ]pyridines with hydroxylamine in alcoholic alkali …”

Section: Introductionmentioning

confidence: 99%