Ueber die Einführung der Benzoyl‐gruppe in tertiäre cyclische Basen

Reissert, Arnold

doi:10.1002/cber.19050380260

Cited by 147 publications

(51 citation statements)

References 7 publications

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“…The marginally better correlation with u,,, (eq. [7]) and the lack of a clear preference for up-indicates that, as expected, resonance stabilization involving W is less important in the transition state for hydroxide ion attack at C-4 than it is in the product (7) itself. Combination of eqs.…”

Section: Discussionmentioning

confidence: 51%

“…Thus the equilibrium ratio of pseudobases ( [7]/ [6]) can be evaluated from eq. [2] for W = CONH?, C02CH3, CN, and NO,, and is included in Table 3.…”

Section: Discussionmentioning

confidence: 99%

“…[9] in this case suggests that, in general, steric effects from C-3 substituents are far less important than electronic effects, a result which is also confirmed by the reasonable correlations obtained in eqs. [4]- [7] where steric effects are ignored. Equations [8] and [9] may also be used to predict second-order rate constants of 1000 M-' s-' and 2 M-' s-' for hydroxide ion attack at C-2 and C-4, respectively, in the parent 1 -methylquinolinium cation.…”

Section: Discussionmentioning

confidence: 99%

“…Thus, whereas cyanide ion addition to the 1-methylquinolinium cation occurs at C-4 to give 1 (5,6), the Reissert compound 2 is isolated from mixtures of quinoline and benzoyl chloride in the presence of cyanide ion and is presumably formed by addition of cyanide ion at C-2 of the 1-benzoylquinolinium cation (7). For neither 1 nor 2 is it clear whether these are the products of kinetic or thermodynamic control.…”

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confidence: 99%

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Kinetic and thermodynamic control of pseudobase formation from C-3 substituted 1-methylquinolinium cations

Bunting¹,

Fitzgerald²

1984

Can. J. Chem.

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. Can. J. Chem. 62, 1301 (1984). The kinetic and thermodynamic control of pseudobase formation from 3-W-1-methylquinolinium cations has been studied for a variety of substituents (W). Spectral data indicate that, in both aqueous and methanolic solution, the C-2 pseudobases predominate at equilibrium for W = H and Br, while the C-4 pseudobases are the thermodynamically preferred species for W = CONH,, C02CH3, CN, and NO2. Stopped-flow studies indicate that in all cases the C-2 pseudobases are the kineticallycontrolled products upon basification of the aqueous solutions of these cations. Equilibrium constants (pKR+) have been measured for pseudobase formation at both C-2 and C-4 for each4W in all cases where they are experimentally accessible.Substituent effecJs upon p~: + correlate with u,, for W, while pKR+ depends upon ul,-. These substituent effects allow the prediction of pKR+ = 15.4 and p~: + = 17.4 for the I-methylquinolinium cation. Rates of C-2 to C-4 pseudobase equilibration have been measured in all cases where the latter species is thermodynamically more stable. These kinetic data allow the evaluation of rate constants for C-4 pseudobase equilibration with each cation. In all cases except W = CN, C-2 pseudobase formation is complete within the mixing time of the stopped-flow instrument. JOHN W. BUNTING et NORMAN P. FITZGERALD. Can. J. Chem. 62, 1301 (1984). On a ttudit le contr8le cinCtique et thermodynamique de la formation de pseudobases h partir de cations W-3 mCthyl-l quinolinium portant plusieurs substituants W. Les donnCes spectrales indiquent que, tant en solution aqueuse que mCthanolique, les pseudobases en C-2 prCdominent h 1'Cquilibre lorsque W = H ou Br alors que les pseudobases en C-4 sont les espkces thermodynamiquement prtfCrCes lorsque W = CONH2, C02CH3, CN et NO2. Des Ctudes par flux stoppC indiquent que, dans tous les cas, les pseudobases en C-2 sont les produits de contr8le cinCtique lorsque les solutions aqueuses de ces cations sont rendues basiques. On a mesurt les constantes dlCquilibre (pKR+) pour la formation de pseudobases tant en C-2 qu'en C-4 pour tous les substituants W dans tous les cas oh ceci Ctait exptrimentalfment possible. On a pu Ctablir une correlation entre les effets des substituants sur les p$+ et les u,,, des W; les valeurs de pKR+ dCpendent de up-. Ces effets de substituants permettent de prtdire des valeurs de pKR+ = I5,4 et p~: + = 17,4 pour le cation methyl-l quinolinium.

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Section: Discussionmentioning

confidence: 51%

“…Thus the equilibrium ratio of pseudobases ( [7]/ [6]) can be evaluated from eq. [2] for W = CONH?, C02CH3, CN, and NO,, and is included in Table 3.…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Kinetic and thermodynamic control of pseudobase formation from C-3 substituted 1-methylquinolinium cations

Bunting¹,

Fitzgerald²

1984

Can. J. Chem.

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“…Since Reissert compounds represent a special class of α-(acylamino)nitriles, it appeared worthwhile to test the reaction of 12 [10,11] with formic acid. As Reissert analogs derived from 3,4-dihydro heterocyclic precursors fail to undergo the Reissert reaction [12], the 3,4- For the reaction of α-acylaminonitriles with formic acid we propose a mechanism, in which the α-acylamino group acts by neighbouring group participation.…”

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confidence: 99%

A Selective Conversion of Nitriles into Carboxamides by Formic Acid

2000

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The thiocarbonyl group of N-acylated cyanothioformamides exhibits pronounced dienophilic reactivity. Thus, with a variety of 1,3-dienes, we obtained the corresponding Diels-Alder adducts 1 [1].Investigating possible transformations of adducts 1, we observed that dissolving them in concentrated formic acid at room temperature resulted in a specific conversion of the nitrile moiety into the corresponding carboxamides 2a -e,g,h with concomitant formation of one mole of carbon monoxide. In most cases, the reaction was complete within 15 -20 minutes and the amides could be isolated in 22 -94% yield (Scheme1). Abstract. Aliphatic α-(acylamino)nitriles react with formic acid at room temperature to give the corresponding α-(acylamino)carboxamides with concomitant formation of one mole of carbon monoxide. This new reaction, which was first observed with 2-acylamino-2-cyano-3,6-dihydro-2H-thiapyIn contrast to reported conversions of nitriles into carboxamides by formic acid which require either heating at 180 -200 °C [2], or the presence hydrogen halides [3], our reaction occurs under rather mild conditions. In order to determine the structural features essential for this conversion and to study its scope, several other α-aminonitriles were treated with formic acid at room temperature. Neighbouring GroupBecause the two α-aminonitriles 1f and 1i [1], both lacking the N-acyl functionality present in the other members of the group, were not altered by formic acid at room temperature, we came to the conclusion that the N-acyl group is essential for the reaction and that other special features such as the thioether moiety present in the Diels-Alder adducts 1 are no prerequisites for the reaction. Accordingly, N-(cyanomethyl)benzanilide (3) [4] after 3 h gave the corresponding acetamide 4 in 93% yield together with 0.9 equivalents of carbon monoxide. The two cyano groups in N,N-bis(cyanomethyl)benzamide (5) [5] could also be converted into carboxamido groups, affording the triamide 6 in 74% yield. In this case, measured by the rate of carbon monoxide evolution, the conversion of the first nitrile needed about 16 h, whereas the whole reaction was complete after about 64 h (Scheme 2).Whereas compounds 1, 3 and 5 on treatment with formic acid yielded the corresponding amides, 2-(Nphenylbenzamido)isobutyronitrile (7) [6], the only other nitrile without α-hydrogen atoms studied, afforded 83% of acid 8 together with only 5% of amide 9.In a one-pot reaction α-(N-formyl)carboxamides 11a -c could be synthesized from α-aminonitriles 10a -c usranes 1, can also be used to convert other N-(α-cyanoalkyl) amides such as N-cyanomethylbenzamides 3, 5 and the 3,4-dihydro Reissert compound 16 into the corresponding carboxamides. Another application is a synthesis of 2-formylaminoacetamides 11. A mechanism for the reaction is proposed.

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Ueber die Einführung der Benzoyl‐gruppe in tertiäre cyclische Basen

Cited by 147 publications

References 7 publications

Kinetic and thermodynamic control of pseudobase formation from C-3 substituted 1-methylquinolinium cations

Kinetic and thermodynamic control of pseudobase formation from C-3 substituted 1-methylquinolinium cations

A Selective Conversion of Nitriles into Carboxamides by Formic Acid

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