Synthesis of the first unsymmetrical macroheterocycle containing endocyclic phosphorus atoms from pyrocatechol and hydroquinone

Article abstract of DOI:10.1134/S1070363209020066

The first unsymmetrical phosphorus(III)-containing macrocycle having hydroquinone and pyrocatechol fragments, N,N,N′,N′-tetraethyl-2,4, 11,13-tetraoxa-3,12-diphosphatricyclo[12.2.2.0^5,10]octadeca-1(16),5, 7,9,14,17 hexaene-3,12-diamine, was syn

Full text of DOI:10.1134/S1070363209020066

ISSN 1070-3632, Russian Journal of General Chemistry, 2009, Vol. 79, No. 2, pp. 200–202. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © Yu.I. Blokhin, K.N. Kornilov, Yu.V. Volchenkova, 2009, published in Zhurnal Obshchei Khimii, 2009, Vol. 79, No. 2, pp. 212–214.
Synthesis of the First Unsymmetrical Macroheterocycle
Containing Endocyclic Phosphorus Atoms
from Pyrocatechol and Hydroquinone
Yu. I. Blokhin, K. N. Kornilov, and Yu. V. Volchenkova
Moscow State University of Technology and Management, ul. Nikoloyamskaya 30, Moscow, 109004 Russia
e-mail: orgchim@mail.ru
Received September 25, 2008
Abstract—The first unsymmetrical phosphorus(III)-containing macrocycle having hydroquinone and pyrocatechol
fragments, N,N,N′,N′-tetraethyl-2,4,11,13-tetraoxa-3,12-diphosphatricyclo[12.2.2.05,10]octadeca-1(16),5,7,9,14,17-
hexaene-3,12-diamine, was synthesized in a stepwise mode from hexaethylphosphorous triamide, hydro-
quinone, and pyrocatechol. The product was converted into the corresponding P,P′-dioxide and P,P′-disulfide.
DOI: 10.1134/S1070363209020066
We recently synthesized a novel unsymmetrical
phosphorus-containing macrocycle incorporating resor-
cinol and pyrocatechol fragments [1]. Such compounds
attract interest as promising multidentate ligands which
could give rise to catalytically active complexes with
transition metals, as well as for the design of supra-
molecular systems [2].
pyrocatechol and hydroquinone fragments. In fact,
molecular assembly of V through intermediate bis-
phosphorylated hydroquinone III took a fairly long
time and was accompanied by formation of a number
of by-products, as we showed previously using various
methods (including MALDI mass spectrumetry) [3].
Compound III was proposed as intermediate in the
synthesis of V, taking into account that analogous bis-
phosphorylated pyrocatechol could not be obtained [1].
Compound V was isolated as a crude product; attem-
pted vacuum distillation resulted in its decomposition
[4]. However, the corresponding oxidation and sulfuriza-
tion products were isolated as individual substances by
column chromatography.
In continuation of this study, in the present work we
synthesized a new unsymmetrical macrocycle contain-
ing endocyclic phosphorus atoms and pyrocatechol and
hydroquinone fragments [3] (Scheme 1).
Presumably, macrocyclic compound V should be
characterized by considerable internal strain difference
in the distances between the hydroxy groups in the
Scheme 1.
CH3COOEt, 20oС
HO
(Et2N)2PO
OH + 2 P(NEt2)3
OP(NEt2)2
−2 HNEt2
I
II
III
O
O
CH3COOEt, 20oС
Et2N
P
P
NEt2
O
O
HO
OH
IV
V
200

SYNTHESIS OF THE FIRST UNSYMMETRICAL MACROHETEROCYCLE
201
dioxane (3:1, A) or chloroform–ethanol (5:1, B) as
eluent. Spots were visualized by treatment with iodine
vapor or calcination. The MALDI mass spectra were
recorded on a Bruker Daltonics instrument. The 31P
NMR spectra of V and VI in ethyl acetate and of VII
in benzene were measured on a Bruker WP-80SY
spectrometer (32.4 MHz) relative to 85% phosphoric
acid. All syntheses were performed in hermetically
closed vessels; the solvents were dehydrated and
purified according to standard procedures.
The oxidation of V gave P,P′-dioxide VI (Scheme 2).
The structure of VI was confirmed by the TLC, 31P
NMR, and mass spectral data. It was isolated as a red–
brown viscous oil.
It is known that sulfurization of analogous
macrocyclic bis-phosphoramidite on the basis of
pyrocatechol and resorcinol leads to decomposition of
the initial compound [1]. Sulfurization of crude
product V gave a compound which displayed two
signals at δP 66.66 and 66.02 ppm in the 31P NMR
spectrum. The mass spectrum of the product was also
consistent with structure VII (Scheme 3).
Hexaethylphosphorous triamide (II) was syn-
thesized as described in [5].
N,N,N′,N′-Tetraethyl-2,4,11,13-tetraoxa-3,12-di-
phosphatricyclo[12.2.2.05,10]octadeca-1(16),5,7,9,14,17-
hexaene-3,12-diamine (V). Compound II, 1.08 g, was
added under stirring to a mixture of 0.24 g of
hydroquinone and 32 ml of ethyl acetate. After 24 h,
0.24 g of pyrocatechol in 5 ml of ethyl acetate was
added, and the mixture was kept for 24 h more. The
solvent was distilled off under reduced pressure to
leave a light yellow oily substance. Rf 0.63 (A). 31P
NMR spectrum, δP, ppm: 142.66, 143.67.
N,N,N′,N′-Tetraethyl-2,4,11,13-tetraoxa-3λ5,125-
diphosphatricyclo[12.2.2.05,10]octadeca-1(16),5,7,9,14,17-
hexaene-3,12-diamine 3,12-dioxide (VI). Compound
II, 2.2 g, was added under stirring to a mixture of
Apart from the signals belonging to P,P′-disulfide
VII, the 31P NMR spectrum of the reaction mixture
contained signals assignable to linear compounds VIII
and IX which were likely to be formed according to
Scheme 4.
Phosphoramidothioate VII was separated from
impurities VIII and IX by column chromatography.
EXPERIMENTAL
Silica gel L (100–250 μm) was used for column
chromatography. Analytical thin-layer chromatography
was performed on Silufol plates using benzene–
Scheme 2.
O
O
O
O
O2
Et2N
P
P
NEt2
Et2N
O
P
P
NEt2
O
O
O
O
O
VI
V
Scheme 3.
O
O
O
O
2S
Et2N
P
P
NEt2
Et2N
P
P
NEt2
S
S
O
O
O
O
VII
V
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 79 No. 2 2009

202
BLOKHIN et al.
Scheme 4.
CH3COOEt, 20oС
(Et2N)2PO
OP(NEt2)2
Et2N
NEt2
HO
P
O
O
P
O
O
OH
HO
OH
IV
VIII
III
S
Et2N
NEt2
HO
P
S
O
O
P
S
O
O
OH
IX
0.60 g of hydroquinone and 30 ml of ethyl acetate. The
mixture was kept for 24 h, 0.6 g of pyrocatechol was
added, and the mixture was kept for 24 h and was then
stirred for 24 h on exposure to air. During this process,
the originally colorless solution turned pink and then
red–brown. The solvent was distilled off under reduced
pressure, and the residue was subjected to column
chromatography using chloroform–ethanol (5:1) as
eluent. Removal of the solvent gave a red–brown
viscous oil which was evacuated for 2 h at 50°C (10
mm). Yield 1.18 g (51%), Rf 0.70 (B). 31P NMR
spectrum: δP 2.50 ppm, br. Found, %: C 52.76; H 6.32;
P 13.40. C20H28N2O6P2. Calculated %: C 52.86; H
6.16; P 13.58. [M + H]+ 455.4, [M + K]+ 493.6.
chromatography using benzene as eluent. Removal of
the solvent gave a red–black viscous oil which was
dried under reduced pressure (10 mm, 50°C, 2 h).
Yield 1.12 g (42%), Rf 0.63 (A). 31P NMR spectrum,
δP, ppm: 66.66, 66.02. Found, %: C 49.06; H 6.02; P
12.64. C20H28N2O6P2S2. Calculated %: C 49.38; H
5.76; P 12.73. [M + H]+ 487.5, [M + K]+ 525.6.
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N,N,N′,N′-Tetraethyl-2,4,11,13-tetraoxa-3λ5,12λ5-
diphosphatricyclo[12.2.2.05,10]octadeca-1(16),5,7,9,14,17-
hexaene-3,12-diamine 3,12-disulfide (VII). Compound
II, 2.2 g, was added under stirring to a mixture of
0.60 g of hydroquinone and 30 ml of ethyl acetate. The
mixture was kept for 24 h, 0.6 g of pyrocatechol was
added, the mixture was kept for 24 h, and the solvent
was distilled off. Elemental sulfur, 0.35 g, and
benzene, 10 ml, were added, the mixture was kept for
24 h, the solvent was distilled off under reduced
pressure, and the residue was subjected to column
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RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 79 No. 2 2009