The radical-induced decomposition of 2-methoxyphenol

Abstract

The thermolysis of 2-methoxyphenol has been studied between 680 and 790 K, applying cumene as a radical scavenger. Two pathways were observed: a homolytic route involving the cleavage of the methoxyl O–C bond, leading to methane and 1,2-dihydroxybenzene, obeying k_uni (s^–1) = 10^{15.2 ± 0.2} exp(–239 ± 8 (kJ mol^–1)/RT), and an induced route starting with abstraction of the phenolic hydrogen by cumyl radicals. After intramolecular hydrogen transfer a cascade of reactions yields phenol, 2-hydroxybenzaldehyde, and 2-hydroxybenzyl alcohol. The latter compound decomposes instantaneously into o-quinone methide (o-QM) which is reduced to o-cresol.

References

1. E. Dorrestijn, L. J. J. Laarhoven, I. W. C. E. Arends and P. Mulder, J. Anal. Appl. Pyrolysis, in the press.
2. (a) A. Vuori, Fuel, 1986, 65, 1575; (b) M. M. Suryan, S. A. Kafafi and S. E. Stein, J. Am. Chem. Soc., 1989, 111, 1423; (c) M. M. Suryan, S. A. Kafafi and S. E. Stein, J. Am. Chem. Soc., 1989, 111, 4594; (d) C. P. Masuku, Acta Polytech. Scand., Chem. Technol. Metall. Ser., 1991, 196, 1; (e) A. Vuori and J. B. Bredenberg, Holzforschung, 1984, 38, 133; (f) I. A. Shkrob, M. C. Depew and J. K. S. Wan, Res. Chem. Intermed., 1992, 17, 271; (g) L. A. Edye and G. N. Richards, Environ. Sci. Technol., 1991, 25, 1133; (h) A. I. Vuori and J. B. Bredenberg, Prepr. Pap. — Am. Chem. Soc., Div. Fuel Chem., 1981, 30, 366; (i) M. T. Klein and P. S. Virk, Prepr. Pap. — Am. Chem. Soc., Div. Fuel Chem., 1980, 25, 180; (j) A. I. Vuori and J. B. Bredenberg, Ind. Eng. Chem. Res., 1987, 26, 359; (k) S. J. Hurff and M. T. Klein, Ind. Eng. Chem., Fundam., 1983, 22, 426; (l) J. R. Lawson and M. T. Klein, Ind. Eng. Chem., Fundam., 1985, 24, 203; (m) J. B. Bredenberg, M. Huuska and P. Toropainen, J. Catal., 1989, 120, 401; (n) J. B. Bredenberg and R. Ceylan, Fuel, 1983, 62, 342; (o) S. E. Stein and M. M. Suryan, in 1987 International Conference on Coal Science, ed. J. A. Moulijn, Elsevier Sci. Publ., Amsterdam, 1987, pp. 749–756; (p) M. Funaoka and I. Abe, Wood Sci. Technol., 1987, 21, 261; (q) R. Ceylan and J. B. Bredenberg, Fuel, 1982, 61, 377.
3. G. J. Schraa, I. W. C. E. Arends and P. Mulder, J. Chem. Soc., Perkin Trans. 1, 1994, 2, 189.
4. (a) E. Dorrestijn, M. Kranenburg, M. V. Ciriano and P. Mulder, J. Org. Chem., in the press; (b) E. Dorrestijn, S. Hemmink, G. Hulstman, L. Monnier, W. van Scheppingen and P. Mulder, Eur. J. Org. Chem., in the press.
5. W. G. Mallard, F. Westley, J. T. Herron and R. F. Hampson, NIST Chemical Kinetics Database, version 5.0, NIST Standard Reference Data, National Institute of Standards and Technology: Gaithersburg, MD, 1993.
6. (a) E. Dorrestijn, R. Pugin, M. V. Ciriano Nogales and P. Mulder, J. Org. Chem., 1997, 62, 4804; (b) E. Dorrestijn, O. J. Epema, W. B. van Scheppingen and P. Mulder, J. Chem. Soc., Perkin Trans. 2, 1998, 1173.
7. P. E. Savage, Energy Fuels, 1995, 9, 590.
8. S. E. Stein, J. M. Rukkers and R. L. Brown, NIST Structures and Properties Database, version 2.0, NIST Standard Reference Data, National Institute of Standards and Technology: Gaithersburg, MD, 1994.
9. I. W. C. E. Arends, R. Louw and P. Mulder, J. Phys. Chem., 1993, 97, 7914.
10. D. D. M. Wayner, E. Lusztyk, K. U. Ingold and P. Mulder, J. Org. Chem., 1996, 61, 6430.
11. M. Jonsson, J. Lind, T. E. Eriksen and G. Merrényi, J. Chem. Soc., Perkin Trans. 2, 1993, 1567.
12. C. Hansch, A. Leo and R. W. Taft, Chem. Rev., 1991, 91, 165.
13. M. F. R. Mulcahy, B. G. Tucker, D. J. Williams and J. R. Wilmshurst, Aust. J. Chem., 1967, 20, 1155.
14. K. Brezinsky, T. A. Litzinger and I. Glassman, Int. J. Chem. Kinet., 1984, 16, 1053.
15. M. I. de Heer, H.-G. Korth and P. Mulder, J. Org. Chem., submitted.
16. A. M. Mebel and M. C. Lin, J. Am. Chem. Soc., 1994, 116, 9577.
17. I. W. C. E. Arends and P. Mulder, Energy Fuels, 1996, 10, 235.
18. D. Santoro, H.-G. Korth and P. Mulder, J. Am. Chem. Soc., submitted.