Russian Journal of Applied Chemistry, Vol. 75, No. 6, 2002, pp. 962 964. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 6, 2002,
pp. 979 981.
Original Russian Text Copyright
2002 by Kalechits, Osinovskii, Matveenko, Ol’khovik.
ORGANIC SYNTHESIS
AND INDUSTRIAL ORGANIC CHEMISTRY
Synthesis of 2-Hydroxy-1-Naphthaldehyde under Conditions
of Heterogeneous Catalysis
G. V. Kalechits, A. G. Osinovskii, Yu. V. Matveenko, and V. K. Ol’khovik
Institute of Chemistry of New Materials, Belarussian National Academy of Sciences, Minsk, Belarus
Received February 7, 2002
Abstract A procedure was developed for synthesis of 2-hydroxy-1-naphthaldehyde by Reimer Tiemann
fluorination of 2-naphthol under conditions of heterogeneous catalysis.
Aromatic o-hydroxy aldehydes readily enter cycli-
with the formation of dibenzoxanthene derivatives
zations and are therefore important synthetic precur- and oligomeric substances contaminating the target
sors of carbocyclic and heterocyclic compounds. For
example, 2-hydroxy-1-naphthaldehyde I is widely used
for preparing various luminophores, optical whiteners
[1, 2], analytical reagents [3], and drugs.
product was noted in [11].
Aldehyde I was prepared by the scheme
OH
In synthesis and study of various benzocoumarin
derivatives, a need arose for relatively large amounts
of I. Published procedures for preparing I [4 7], de-
spite high yields (up to 80%), are complicated by
use of expensive and deficient reagents, which are
often toxic.
II
CHO
(1) CHCl3, NaOH, H2O, dioxane,R4N+Cl , 60 70 C;
(2) H+
OH
The most acceptable route to I, free of the above
drawbacks, is formylation of 2-naphthol II by the
Reimer Tiemann reaction; however, in the classical
version of this procedure, the yields are as low as
38 48% [8], and isolation of a high-purity product
is difficult, which makes this procedure unsuitable for
large-scale syntheses.
I
It is well known that the reactive species in the
Reimer Tiemann reaciton is dichlorocarbene :CCl2.
The mechanism of dichlorocarbene generation under
conditions of heterogeneous catalysis is also under-
stood in detail [12]. The reaction scheme can be de-
scribed as follows. At the phase boundary, chloroform
is deprotonated to give trichloromethylide anion:
To raise the yield and obtain high-purity product,
we examined the possibility of formylation of II with
chloroform in alkaline solution under conditions of
heterogeneous catalysis [9]. Although the Reimer
Tiemann reaction usually does not require catalysts,
it was shown in [10] that the use of tertiary ammo-
nium salts for preparing salicylaldehyde from phenol
increases the yield of the target product by more than
a factor of 2.
HCCl3(org. phase) + Na(+aq. phase) + OH(aq. phase)
CCl3(interface) + Na(+interface) + H2O.
(1)
This is followed by exchange with the quaternary
ammonium salt (2) and generation of carbene (3) (the
reaction is reversible):
Along with the low cost and availability of the
starting compounds (naphthol II, chloroform, alkali),
an advantage of the heterogeneous-catalytic synthesis
in alkaline solution is the formylation at the o-posi-
tion and the minimum extent of condensation of the
forming aldehyde I with the initial naphthol II. The
possibility of such a condensation in acid solutions
CCl3(interface) + [R4N+X ](org. phase)
[R4N+CCl3](org. phase) + X(aq. phase)
[R4N+CCl3](org. phase)
[R4N+Cl ](org. phase) + [CCl2](org. phase)
,
(2)
(3)
.
1070-4272/02/7506-0962 $27.00 2002 MAIK Nauka/Interperiodica