~ APPLIED
CATALYSIS
A: GENERAL
ELSEVIER Applied Catalysis A: General 144 (1996) LI-L5
Letter
Continuous alkylation of 5-methoxy-1-naphthol and
4-methyl-1-naphthol with alcohols over an iron
catalyst
a
Mi~ta
a
b
Hanna Grabowska Wtodzimierz Ludwik Syper
J6zef Wrzyszcz a,*, Miroslaw Zawadzki a
a W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O.
Box 937, 50-590 Wroctaw 2, Poland
Institute of Organic Chemistry, Biochemistry and Biotechnology, Technical University of Wroctaw, Wybrze~e
Wyspiafiskiego St. 27, 50-370 Wroctaw, Poland
Received 25 March 1996; revised 17 April 1996; accepted 17 April 1996
Abstract
The vapour phase alkylation of 5-methoxy-l-naphthol and 4-methyl-l-naphthol with alcohols
in the presence of an iron catalysts (magnetite) that contained Cr-, Si- and K oxides was
investigated. At temperatures of 580-655 K alkylderivatives with high yield in ortho-position to
the hydroxyl group were obtained. The reactions were carried out in an continuous process at
atmospheric pressure.
Keywords: Catalytic alkylation; lron catalysts; Alkylonaphthols; 2-Methyl-5-methoxy-l-naphthol; 2n-Butyl-5-
methox y- 1 -naphthol; 2-Ethyl-4-methyl- l-naphthol
We have recently demonstrated that in the presence of an iron catalyst 1- and
2-naphthols can be efficiently and selectively alkylated with C ~-C 5 alcohols in
a reaction run at atmospheric pressure in a flow reactor. For 1-naphthol, the
alkyl group enters position 2, while for 2-naphthol, 1-alkyl-2-naphthol is
obtained first and 1,3-dialkyl-2-naphthol later in amounts depending on the
reaction conditions [1]. The mechanism of the described reactions is not clear. It
is well known that alcohols and hydroxyarenes are chemisorbed over the metal
oxide surfaces as alcoxides and naphthols as naphthoxides, respectively. Both
Corresponding author. Tel.: (+48-71) 3435021; fax: (+48-71)
wrzyszcz @ highscreen.int.pan.wroc .pl.
0926-860X/96/$15.00 Copyright © 1996 Elsevier Science B.V. All rights reserved.
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