Russian Journal of General Chemistry, Vol. 71, No. 10, 2001, pp. 1545 1546. Translated from Zhurnal Obshchei Khimii, Vol. 71, No. 10, 2001,
pp. 1632 1633.
Original Russian Text Copyright
2001 by Bidman.
Reaction of Triphenylphosphine Oxide
with ortho-Dihydroxyaromatic Compounds
T. A. Bidman
Institute of Chemistry and Chemical Technology, Siberian Division, Russian Academy of Sciences, Krasnoyarsk, Russia
Received May 22, 2000
Abstract Triphenylphosphine oxide was first reacted with 2,3-dihydroxynaphthalene, as well as with halo-
and alkyl-substituted 1,2-dihydroxybenzenes to obtain the corresponding (ortho-naphthylenedioxy)- or
(ortho-phenylenedioxy)triphenylphosphoranes.
It is known that pyrocathechol (1,2-dihydroxy-
benzene) reacts with dichlorotriphenoxyphosphorane
to form triphenoxy(1,2-phenylenedioxy)phosphorane
Alkyl- and halo-substituted 1,2-dihydroxybenzenes
presented in the table react analogously. The reactions
proceed quantitatively, as evidenced by the absence
of the absorption band at 1190 cm 1 (P=O) and of the
starting compound in the IR spectra of the reaction
products. The latter spectra also show no OH stretch-
ing vibration bands of the starting dihydroxy com-
[
1]. The reaction of pyrocathechol with phosphonites
in the presence of bases gives phosphoranes and
hydrogen [2]. The reaction of pyrocatechol with
phosphorus trichloride affors three products [3],
while with phosphorus pentachloride several com-
pounds are formed [1]. These examples include
almost all known reactions of ortho-dihydroxyaro-
1
pound at 3470 and 3350 cm in KBr pellets or at
3620 and 3570 cm 1 in CCl solutions. The IR spectra
4
of all the phosphoranes obtained contain bands at
matic compounds with phosphorus halides and organo- 1240 and 1450 cm 1 assignable to P O C and
phosphorus compounds. Evidently, the reactivity of
the P=O group in phosphine oxides toward ortho-di-
P C H stretching vibrations, respectively, but with
compounds containing alkyl-substituted benzene rings
6 5
hydroxyaromatic compounds has not yet been studied. such assignment is complicated by the presence of
deformation and skeletal vibration bands of these
The present communication presents the results of
substituents in the same spectral region. Note that the
first performed reactions of triphenylphosphine I with
new reaction studied provides a preparative route to
ortho-dihydroxynaphthalenes and halo- and alkyl-
prosphoranes containing a dioxaphospholene hetero-
substituted ortho-dihydroxybenzenes.
ring.
Whereas the phosphoryl group was previously
considered rather inert, at present a great number of
reactions with its participation are known. The reac-
tion of phosphine I with ortho-dihydroxyaromatic
compounds which are acidic in nature most probably
begins with protonation of the oxygen atom of the
electron-donor phosphoryl group. The resulting inter-
mediate complex contains three oxygen atoms sur-
rounding the phosphorus atom, and it is stabilized by
elimination of one water molecule. Hence, the reac-
tion of 2,3-dihydroxynaphthalene with phosphine
EXPERIMENTAL
The IR spectra were recorded on an IKS-22 spec-
trometer in KBr pellets in the range 4000 400 cm .
1
The starting 4-bromo-1,2-dihydroxybenzene and
-bromo-5-tert-butyl-1,2-dihydroxybenzene were
prepared by the bromination of 1,2-dihydroxybenzene
and 4-tert-butyl-1,2- dihydroxybenzene according to
3
[
4]. 4-tert-Butyl-1,2-dihydroxybenzene and 4-cyclo-
hexyl-1,2-dihydroxybenzene were prepared by the
alkylation of pyrocatechol with corresponding alcohol
according to [5] or [6]. Commercial 1,2-dihydroxy-
benzene and 2,3-dihydroxynaphthalene were purified
by sublimation.
I
yields (2,3-naphthylenedioxy)triphenylphospho-
rane V.
OH
OH
+
(C H ) P=O
6 5 3
Reaction of triphenylphosphine oxide with ortho-
dihydroxyaromatic compounds. A mixture of
O
O
P(C H )
6
5 3
H O
2
0.005 mol of triphenylphosphine oxide and 0.005 mol
1
070-3632/01/7110-1545$25.00 2001 MAIK Nauka/Interperiodica
Bidman
