The tetrahedral intermediate from the hydration of <i>N</i>-methylformanilide

Guthrie, J. Peter; Barker, Jonathan; Cullimore, Patricia A.; Lu, Jinqiao; Pike, David C.

doi:10.1139/v93-262

Cited by 16 publications

(14 citation statements)

References 30 publications

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“…Thus, our new and more accurate °∆ m f H (liq)-value obtained from combustion calorimetry is consistent with results from previous combustion studies, [24][25][26] as well as with the result from solution calorimetry. 27 As a final proof for our new combustion result could serve a data reported for the following chemical reaction: 28,31 …”

Section: Computation Detailssupporting

confidence: 54%

“…30 The uncertainty assigned to Table 4, column 2). Guthrie et al 27 reported 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 ± 7.5) kJ·mol -1 from equilibrium constants of hydrolysis reaction measured as a function of temperature. This value agrees very well with our result from combustion calorimetry °∆ m f H (liq) = (35.9 ± 2.1) kJ·mol -1 .…”

Section: Computation Detailsmentioning

confidence: 99%

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Benchmark Thermochemistry of N-Methylaniline

et al. 2015

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In this work, the standard molar enthalpy of formation in the gaseous state of highly pure N-methylaniline, Δ(f)H(m)°(g, 298.15 K) = 90.9 ± 2.1 kJ·mol⁻¹, has been obtained from the calorimetrically measured energy of combustion converted into the enthalpy of formation, Δ(f)H(m)°(liq, 298.15 K) = 35.9 ± 2.1 kJ·mol⁻¹, and from the molar enthalpy of vaporization, Δ(l)(g)H(m) = 55.0 ± 0.2 kJ·mol⁻¹, derived from vapor pressure measurements by transpiration method. The enthalpy of formation of N-methylaniline calculated using the quantum chemical G4 method was in excellent agreement with the experimental value. The frequencies of normal vibrations were obtained from the experimental and calculated spectra. Thermodynamic properties of N-methylaniline in the ideal gas state were calculated from molecular and spectral data in the temperature range 100-1500 K.

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Section: Computation Detailssupporting

confidence: 54%

Section: Computation Detailsmentioning

confidence: 99%

Benchmark Thermochemistry of N-Methylaniline

et al. 2015

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“…These results for acetic acid, pKE = 19.4 + 1.3, may be compared with expectations based on disproportionation calculations, where the en01 content of acetic acid was predicted to be pKE = 21 + 2 (8), or the prediction based on deuterium exchange into acetic acid, pKE = 19.3 + 2.2 (8).…”

Section: Discussionmentioning

confidence: 72%

“…As yet the only routes to the en01 content of acetic acid are an indirect thermodynamic argument that we have presented (8), and an indirect kinetic analysis of deuterium exchange kinetics (8). The carbon pK, values of acetic acid (8) and ethyl acetate (9) have been calculated from kinetics of exchange.…”

Section: Introduction Resultsmentioning

confidence: 99%

The enols of acetic acid and methyl acetate

Guthrie¹,

Li²

1995

Can. J. Chem.

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Abstract:We have determined the heat of formation of 1,l-dimethoxyethene, AHf(l) = -75.56 ? 0.87 kcal mol-I, by measuring the heat of hydrolysis. The heat of vaporization, 8.47 ? 0.10 kcal mol-I, was estimated from the boiling points at various pressures. The standard entropy of gaseous 1,l-dimethoxyethene, 82.02 ? 2. cal deg-' mol-', was calculated using frequencies obtained by M O calculations at the 6-31G** level. The free energy of transfer, 1.02 2 1, was estimated by additivity with allowance for a distant polar interaction. Thus the free energy of formation in aqueous solution, AGf(aq) = -37.07 ? 1.48 kcal rnol-', could be calculated. ' The free energies of hydrolysis for en01 ethers appear to be insensitive to structure; we used an average value and so calculated the values of the free energies of formation of the enols of acetic acid and methyl acetate, -67.90 2 1.67 and -52.48 2 1.53 kcal mol-I, respectively. These values are in good agreement with other recent evaluations. This method should be applicable to related enols.Key words: enols, thermodynamics, heat of formation, entropy, ketene acetal.

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“…The calculated AH$'s shown in Table 5 (8.G10.0 kcallmol) fall in the range of the experimental values (Table l), but the magnitudes are reversed. While the rate-determining steps for the hydrolyses of l a , l b , and l c are not known with certainty, the work of Guthrie et al -the calculated AG$for heterolysis of the HN+-C(OH), bond of the N-protonated hydrate of N-methylformanilide where relief of strain is not an important factor is 12.4 kcal/mol -provides support for the calculational results (18). The computed potential energy profile for heterolysis of 10a.2H20 is displayed in Fig.…”

Section: Hydrolysis Of N-protonated Amidesmentioning

confidence: 81%

An AM1 calculational study of the protonation and reactions of 3,4-dihydro-2-oxo-1,4-ethanoquinoline, 3,4-dihydro-2-oxo-1,4-propanoquinoline, 3,3,4,5-tetrahydro-2-oxo-1,5-ethanobenzazepine, 3,3,4,5-tetrahydro-2-oxo-1,5-propanobenzazepine, and N-methyl-4-bromo-2-methylacetanilide

Brown¹,

Wang²

1996

Can. J. Chem.

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Abstract:The gas phase N-and 0-protonation of distorted amides 3,4-dihydro-2-0x0-1.4-ethanoquinoline (la), 3,4-dihydro-2-0x0-l,4-propanoquinoline (lb), 3,3,4,5-tetrahydro-2-0x0-1,5-ethanobenzazepine (lc), and 3,3,4,5-tetrahydro-2-0x0-1,5-propanobenzazepine (16) and normal amides 4-bromo-2,N-dimethylacetanilide (5a) and 2,N-dimethylacetanilide (Sb), along with the N-protonation of benzoquinuclidine (7), has been studied calculationally at the semiempirical level of theory with AM 1. Calculated enthalpies of N-and 0-protonation (proton affinities) indicate that l a , lb, and l c should protonate on nitrogen and Id, 5a, and 5b on oxygen. A satisfactory straight-line relationship between the calculated proton affinities of la, lb, lc, and 7 with experimental solution pK,'s is used to estimate the solution pK, of Id. Results of a calculational study on the gas phase N-and 0 -methylation of lb, lc, and I d are nicely in accord with the findings of an experimental solution phase study of the methylationhydrolysis of l b and Id: while l b methylates on nitrogen, Id methylates on oxygen. A calculational study of possible pathways of hydrolysis of the N-protonated amides indicates that solvolysis of the hydrates of these species represents a viable route for their conversion to ring-opened products.Key words: protonation, methylation, reactions, distorted amides, AM1 calculations.

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The tetrahedral intermediate from the hydration of N-methylformanilide

Cited by 16 publications

References 30 publications

Benchmark Thermochemistry of N-Methylaniline

Benchmark Thermochemistry of N-Methylaniline

The enols of acetic acid and methyl acetate

An AM1 calculational study of the protonation and reactions of 3,4-dihydro-2-oxo-1,4-ethanoquinoline, 3,4-dihydro-2-oxo-1,4-propanoquinoline, 3,3,4,5-tetrahydro-2-oxo-1,5-ethanobenzazepine, 3,3,4,5-tetrahydro-2-oxo-1,5-propanobenzazepine, and N-methyl-4-bromo-2-methylacetanilide

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