Res. Chem. Intermed.
, Vol. 27, No. 3, pp. 281–285 (2001)
C-alkylation of m-cresol with n- and iso-propanol
over iron catalyst
H. GRABOWSKA and J. WRZYSZCZ
Department of Catalysis, W. Trzebiatowski Institute of Low Temperature and Structure Research,
Polish Academy of Sciences, 50-950 Wrocaw 2, PO Box 1410, Poland
Received 23 May 2000; accepted 14 September 2000
Abstract—The gas-phase alkylation of m-cresol (3-methylphenol) with n- and
investigated. The reactions were carried out in a continuous process at atmospheric pressure over
an iron catalyst that contains Cr, Si and K oxides. It is possible to obtain n- and
of m-cresol with satisfactory selectivity.
Alkylphenols are important intermediates in the basic chemical industry and in
the synthesis of ne chemicals. Various kinds of plastics, agrochemicals, dyes,
non-ionic detergents, emulsi ers, pharmaceuticals, avouring agents, etc. are
manufactured from them [1, 2]. Alkyl derivatives of phenol also can be useful as
antioxidants in gasoline, plastics, rubber, food and pharmaceuticals protection .
We have demonstrated earlier that iron oxide catalyst is active and selective in
C-alkylation of phenol, 1- and 2-naphthols and some of their derivatives with
alcohols in a continuous process run in a gas-phase at atmospheric pressure .
Also, a reaction mechanism occurring over that catalyst has been proposed .
Alkylation of phenols and some of their derivatives with C
alcohols takes place
at the ortho position to the phenolic hydroxyl group and the reaction has consecutive
character. At lower temperatures the alkyl group enters position 2 in the phenol ring
and at higher temperatures — the 2 and 6 position both [6–9]. When higher alcohols
were used as alkylating agents the yield and selectivity of the reactions decreased
with increasing chain length because these alcohols in the presence of iron catalyst