ENTHALPY–ENTROPY CORRELATIONS
853
distilled off, and the residue was analyzed by GLC.
Each reaction was carried out at 25 and 70°C. The
relative reactivity of PhCO C H R and PhCO C H R′
and IIh) with 2,4-dinitrophenyl benzoate (I) in the
presence of KHCO and K CO in DMF were deter-
mined at 40 (KHCO ) and 0°C (K CO ) according to
3
2
3
2
6
4
2
6
4
3
2
3
–
+
toward potassium phenoxides RC H O K and
the general procedures listed above. The results are
collected in Table 5.
6
4
–
+
R′C H O K at –15 and 40°C was determined in
6
4
a similar way, the reaction time being 5 s. In all cases,
the molar concentration ratios of the corresponding
esters PhCO C H R and PhCO C H R′ did not change.
REFERENCES
2
6
4
2
6
4
1
. Carey, F.A. and Sundberg, R.J., Advanced Organic
Chemistry. Part A: Structure and Mechanisms, New
York: Springer, 2007, 5th ed., chap. 3.
. Adler, M., Adler, S., and Boche, G., J. Phys. Org.
Chem., 2005, vol. 18, p. 193.
For each phenol couple competitive reactions were
performed at equimolar concentrations which exceed-
ed the concentration of the substrate by a factor of 5.
These conditions implied that the concentration ratio
of the products is directly proportional to the ratio of
the second-order rate constants for each reaction [32].
2
3. Williams, A., Concerted Organic and Bio-organic
Mechanisms, Boca Raton, FL: CRC, 2000.
4
5
6
. Um, I.-H., Min, J.-S., Jeon, J.S., and Kwon, D.-S., Bull.
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. Ba-Saif, S.A., Colthurst, M., Waring, M.A., and
Williams, A., J. Chem. Soc., Perkin Trans. 2, 1991,
p. 1901.
Determination of the relative rate constants for
the reactions of phenols IIa–IIh with 2,4-dinitro-
phenyl benzoate (I) in the presence of potassium
hydrogen carbonate in DMF. A mixture of 1 mmol of
potassium hydrogen carbonate and 2–3 ml of a solu-
tion of 0.5 mmol of RC H OH and 0.5 mmol of
6
4
R′C H OH in DMF was stirred at 25±0.2, 40±0.2,
6
4
7
8
9
. Ba-Saif, S., Luthra, A.K., and Williams, A., J. Am.
5
5±0.2, or 70±0.2°C. A solution of 0.1 mmol of com-
Chem. Soc., 1989, vol. 111, p. 2647.
. Os’kina, I.A. and Vlasov, V.M., Russ. J. Org. Chem.,
pound I in 0.3 ml of DMF was adjusted to the same
temperature and added in one portion to the resulting
suspension, the mixture was stirred for 1 h, and a mix-
ture of 3 ml of diethyl ether and 2 ml of water was
added. The organic phase was separated, the aqueous
phase was extracted with diethyl ether (2×3 ml), the
extracts were combined with the organic phase, the
solvent was distilled off, and the residue was analyzed
by GLC. The conditions and results are collected
in Table 1.
2
006, vol. 42, p. 865.
. Khalfina, I.A. and Vlasov, V.M., Russ. J. Org. Chem.,
008, vol. 44, p. 1619.
2
1
0. Hansch, C., Leo, A., and Taft, R.W., Chem. Rev., 1991,
vol. 91, p. 165.
1
1
1
1. Bordwell, F.G. and Cheng, J.P., J. Am. Chem. Soc.,
1
991, vol. 113, p. 1736.
2. Maran, F., Celadon, D., Severin, M.G., and Vianello, E.,
J. Am. Chem. Soc., 1991, vol. 113, p. 9320.
3. Liu, L. and Guo, Q.X., Chem. Rev., 2001, vol. 101,
Determination of the relative rate constants for
the reactions of potassium phenoxides IIIa–IIIh
with 2,4-dinitrophenyl benzoate (I) in DMF. A solu-
p. 673; Linert, W. and Jameson, R.F., Chem. Soc. Rev.,
1
989, vol. 18, p. 477; Linert, W., Chem. Soc. Rev., 1994,
–
+
vol. 23, p. 429; Exner, O., Chem. Commun., 2000,
p. 1655.
tion of 0.5 mmol of RC H O K and 0.5 mmol of
6
4
–
+
R′C H O K in 2–3 ml of DMF was stirred at
6
4
1
4. Ruff, F. and Farkas, Ö., J. Org. Chem., 2006, vol. 71,
p. 3409; Ruff, F., Internet Electron. J. Mol. Des., 2004,
vol. 3, p. 474; Ruff, F., J. Mol. Struct. (Theochem),
–
2
0
15±0.5, 0±0.5, 25±0.2, or 40±0.2°C. If necessary,
mmol of 18-crown-6 was added. A solution of
.1 mmol of compound I in 0.3 ml of DMF, adjusted to
2
003, vol. 625, p. 111; Ruff, F., J. Mol. Struct.
the same temperature, was then added, and the mixture
was stirred for 5 s and treated with a mixture of 3 ml of
diethyl ether and 2 ml of water. The organic phase was
separated, the aqueous phase was extracted with di-
ethyl ether (2×3 ml), the extracts were combined with
the organic phase, the solvent was distilled off, and
the residue was analyzed by GLC. The results are
collected in Table 1.
(Theochem), 2002, vol. 617, p. 31.
15. Leffler, J.E. and Grunwald, E., Rates and Equilibria of
Organic Reactions as Treated by Statistical, Thermo-
dynamic, and Extrathermodynamic Methods, New York:
Wiley, 1963, chap. 9.
6. Um, I.-H., Park, Y.-M., Fujio, M., Mishima, M., and
Tsuno, Y., J. Org. Chem., 2007, vol. 72, p. 4816;
Oh, H.K., Oh, J.Y., Sung, D.D., and Lee, I., J. Org.
Chem., 2005, vol. 70, p. 5624; Castro, E.A., Aguayo, R.,
Bessolo, J., and Santos, J.G., J. Org. Chem., 2005,
vol. 70, p. 7788.
1
D
R
D
H
The relative rate constants k /k for the reac-
tions of deuterated phenols R′C H OD (IIa, IId, IIf,
6
4
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 47 No. 6 2011