One pot synthesis of 3,9-bis-(2,4-di-tert-butyl phenoxy)-2,4,8,10-tetraoxa- 3,9-diphospha-spiro[5.5]undecane, their chalcogenides and metal complexes

Article abstract of DOI:10.14233/ajchem.2013.14068

A simple method for the synthesis of 3,9-di[2,4-di-tert-butyl phenoxy]-2,4,8,10-tetraoxa-3,9-diphospha-spiro[5.5]undecane and its chalcogenides and metal complex are reported.

Full text of DOI:10.14233/ajchem.2013.14068

Asian Journal of Chemistry; Vol. 25, No. 8 (2013), 4556-4558
http://dx.doi.org/10.14233/ajchem.2013.14068
One Pot Synthesis of 3,9-Bis-(2,4-di-tert-butyl phenoxy)-2,4,8,10-tetraoxa-
3,9-diphospha-spiro[5.5]undecane, their Chalcogenides and Metal Complexes
*
MANJU RANI, DAVENDER KUMAR SHUKLA and ARIF ALI KHAN
University School of Basic & Applied Sciences, Guru Gobind Singh Indraprastha University, Dwarka, Sector 16C, New Delhi-110 078, India
*Corresponding author: E-mail: khanaarif@hotmail.com
(Received: 19 May 2012;
Accepted: 15 February 2013)
AJC-13011
A simple method for the synthesis of 3,9-di[2,4-di-tert-butyl phenoxy]-2,4,8,10-tetraoxa-3,9-diphospha-spiro[5.5]undecane and its
chalcogenides and metal complex are reported.
Key Words: Pentaerythritol, 2,4-Di-tert-butylphenol, Diphosphite, Chalcogenides.
temperature chromatography columns were prepared from
Merck silica gel powder. IR spectra were measured on a
Shimadzu IR-460 spectrometer. 1H, 13C and 31P NMR spectra
were recorded on a Bruker AV-300 MHz spectrometer as
CDCl3 solution with TMS as internal and 85 % H3PO4 as
external solution. The methods were used to follow the reactions
were TLC and NMR. TLC and NMR indicated that there is no
side product. Mass spectra were recorded on PDL/ARD-062
mass spectrophotometer.
INTRODUCTION
Organophosphorus compounds are degradable containing
carbon-phosphorus bonds, primarily used in pest control as
an alternative to chlorinated hydrocarbons which persist in
the environment. The importance of organic phosphites as
stablizers for polymers has lead to the development of a variety
of specialty organic phosphites that have enhanced effective-
ness for stabilization1. Phosphorous based derivatives phosphites
and phosphonites are well known to be effective as polymer
stabilizers mainly during processing, acting as secondary
antioxidants and are particularly effective in combination with
phenols. In addition some phosphites and phosphonites can
help in improving the discoloration of polymer articles when
they are exposed to heat, UV light, nitrogen oxides and to γ-
rays. However, phosphorous based stabilizers are sensitive to
heat and moisture so that they can cause undesired side
problems during processing and in the life time of polymer
articles making their benefits2 useless. Prevention of discolo-
ration may require inhibiting reactions which yield new
chromophores or colour bodies in the substrates or stabilizers3.
An antioxidant is a molecule capable of inhibiting the oxidation
of other molecules. In this paper, we report a simple, quick
and cost effective synthesis of highly pure 3,9-bis[2,4-di(tert-
butyl phenoxy]-2,4,8,10-teraoxa-3,9-diphosphaspiro-
[5.5]undecane and its chalcogenides and metal complexes
under mild reaction conditions.
Procedure for the preparation of compounds
3,9-Bis[2,4-di(tert-butyl phenoxy]-2,4,8,10-teraoxa-3,9-
diphosphaspiro[5.5]undecane (1): To a precooled toluene
solution of pentaerythritol (1 mmol) at 5 ºC, a triethyl amine
(5 mmol) was added, followed by phosphorus trichloride (2
mmol) and stirring was continued for 1 h. Then a solution of
2,4 di-tert-butyl phenol in toluene was added to it and refluxed
for 5 h followed by stirring overnight at room temperature.
The reaction solution was filtered and solvent was evaporated
and the product was separated by column chromatography
(SiO2, 5 ºC, hexane:diethyl ether; 99.5:0.5). Evaporation of
the solvents of the second fraction and recrystallization from
diethyl ether at 5 ºC yielded 3,9-bis[2,4-di(tert-butyl phenoxy]-
2,4,8,10-teraoxa-3,9-diphosphaspiro[5.5]undecane as white
crystalline solid, yield 22 %, m.p. 169-170 ºC.
3,9-bis[2,4-di-(tert-butyl phenoxy]-2,4,8,10-teraoxa-
3λ5,9λ5-diphosphaspiro[5.5]undecane-3,9-dioxide (2): To a
precooled dichloromethane solution of 3,9-bis[2,4-di(tert-butyl
phenoxy]-2,4,8,10-teraoxa-3,9-diphosphaspiro[5.5]undecane
(2 mmol) at -80 ºC, a DMSO (3.0 mmol) solution in dichloro-
methane was added dropwise and stirring was continued for
EXPERIMENTAL
Starting materials and solvents were obtained from Merck
and spectrochem and were used with further purification. Low

Vol. 25, No. 8 (2013)
Compound No.
Synthesis of 3,9-Bis-(2,4-di-tert-butyl phenoxy)-2,4,8,10-tetraoxa-3,9-diphospha-spiro[5.5]undecane 4557
TABLE-1
ELEMENTAL ANALYSIS OF COMPOUND (1-5)
Elemental analysis (%) calcd. ( Found)
m.f.
C
H
P
C33H50O6P2
C33H50O8P2
65.49 (65.55)
57.00 (62.25)
54.36 (59.26)
49.16 (51.97)
40.37 (41.24)
8.29 (8.33)
3.73 (7.92)
3.73 (7.54)
3.23 (6.61)
2.10 (4.02)
10.12 (10.24)
3.41 (9.73)
3.38 (9.26)
3.01(8.12 )
1.83 (4.95)
1
2
3
4
5
C33H50O6P2S2
C33H50O6P2Se2
C43H50O16P2W2
TABLE-2
1H NMR SPECTRUM OF COMPOUND (1-5)
1H NMR data
Compound No.
1
2
3
4
5
δ 1.311(s, 18H, t-Bu), 1.437 (s, 18H, t-Bu), 3.457-4.535 (m, 8H, -CH2), 6.977-7.401 (m, 6H, aromatic)
δ 1.300 (s, 18H, t-Bu), 1.428 (s, 18H, t-Bu), 4.228-4.865 (m, 8H, -CH2), 7.194-7.394 (m, 6H, aromatic)
δ 1.272(s, 18H, t-Bu), 1.390 (s, 18H, t-Bu), 3.586-4.569 (m, 8H, -CH2), 7.082-7.332 (m, 6H, aromatic)
δ 1.315(s, 18H, t-Bu), 1.421 (s, 18H, t-Bu), 4.303-4.558 (m, 8H, -CH2), 7.141-7.414 (m, 6H, aromatic)
δ 1.242(s, 18H, t-Bu), 1.466 (s, 18H, t-Bu), 3.627-4.621 (m, 8H, -CH2), 6.979-7.338 (m, 6H, aromatic)
2 h at -80 ºC. The solvent was removed under reduced pressure
and the product was separated by low-temperature column
chromatography (SiO2, 5 ºC, hexane:diethyl ether; 98:2).
Evaporation of the solvents of the second fraction and recrysta-
llization from diethyl ether at 5 ºC yielded 3,9-bis[2,4-di(tert-
butyl phenoxy]-2,4,8,10-teraoxa-3λ5,9λ5-diphosphaspiro-
[5.5]undecane-3,9-dioxide as creamish crystalline material,
yield 63.0 %, m.p. 229-230 ºC.
spiro[5.5]undcane (1 mmol) and W(CO)5CH3CN (1.1 mmol)
in 20 mL THF was stirred at 25-30 ºC for 22 h. The resulting
dark brown solution was filtered under nitrogen and concen-
trated under reduced pressure. The crude product thus obtained
was separated by low-temperature column chromatography
(SiO2, 5 ºC, hexane:diethyl ether; 98:2). Evaporation of the
solvents of the second fraction and recrystallization from
diethyl ether at 5 ºC yielded 3,9-bis[2,4-di(tert-butyl phenoxy]-
2,4,8,10-teraoxa-3λ5,9λ5-diphosphaspiro [5.5]undecane-3,9-
ditungestonpentacarbonyl as off white crystalline solid, yield
78.0 %, m.p. 129-130 ºC.
3,9-Bis[2,4-di(tert-butyl phenoxy]-2,4,8,10-teraoxa-
3λ5,9λ5-diphosphaspiro[5.5]undecane-3,9-disulfide (3): A
solution of 3,9-bis[2,4-di(tert-butyl phenoxy]-2,4,8,10-
teraoxa-3,9-diphosphaspiro[5.5]undecane (1 mmol) and
elemental sulphur (10 mmol) in 20 mL toluene was heated at
108-110 ºC for 24 h. The resulting dark brown solution was
filtered hot under nitrogen and concentrated under reduced
pressure. The crude product thus obtained was separated by
low-temperature column chromatography (SiO2, 5 ºC,
hexane:diethyl ether; 98:2). Evaporation of the solvents of the
second fraction and recrystallization from diethyl ether at 5 ºC
yielded 3,9-bis[2,4-di(tert-butyl phenoxy]-2,4,8,10-teraoxa-
3λ5,9λ5-diphosphaspiro[5.5]undecane-3,9-disulfide as yellow
crystalline powder, yield 54.0 %, m.p. 161-162 ºC.
The analytical, 1H NMR, 31P NMR and 13C NMR spectral
data of all the synthesized compounds 1-4 are given in Tables
1-4, respectively.
TABLE-3
31P NMR SPECTRUM OF COMPOUND (1-5)
Compound No.
31P NMR
Coupling constant
–
1
2
3
4
5
δ 116.480
δ 13.483
δ 55.56
–
–
δ 60.422
δ 130.84
(Triplet, 1JP-Se = 517.061 Hz)
(Triplet, 1JP-W = 204.832 Hz)
3,9-Bis[2,4-di(tert-butyl phenoxy]-2,4,8,10-teraoxa-
3λ5,9λ5-diphosphaspiro[5.5]undecane-3,9-diselone (4): A
solution of 3,9-bis[2,4-di(tert-butyl phenoxy]-2,4,8,10-
teraoxa-3,9-diphosphaspiro[5.5]undecane (1 mmol) and
elemental selenium powder (10 mmol) in 20 mL toluene was
heated at 108-110 ºC for 14 h. The resulting dark brown
solution was filtered hot under nitrogen and concentrated under
reduced pressure. The crude product thus obtained was sepa-
rated by low-temperature column chromatography (SiO2, 5 ºC,
hexane:diethyl ether; 98:2). Evaporation of the solvents of the
second fraction and recrystallization from diethyl ether at 5 ºC
yielded 3,9-bis[2,4-di(tert-butyl phenoxy]-2,4,8,10-teraoxa-
3λ5,9λ5-diphosphaspiro[5.5]undecane-3,9-diselone as orange
colour crystalline solid, yield 49.0 %, m.p. 220-221 ºC.
Preparation of 3,9-bis[2,4-di(tert-butyl phenoxy]-
2,4,8,10-teraoxa-3λ5,9λ5-diphosphaspiro[5.5]undecane-3,9-
ditungestonpentacarbonyl (5): A solution of 3,9-bis[2,4-
di(tert-butyl)phenoxy]-2,4,8,10-teraoxa-3,9-diphospha-
RESULTS AND DISCUSSION
In the last few years, several synthetic methods have been
reported for the preparation of 3,9-bis[2,4-di(tert-butyl)-
phenoxy]-2,4,8,10-teraoxa-3,9-diphosphaspiro[5.5]-undecane
(1). There are several reports for the use of 1 in the antioxidation
property. Even the process of this invention utilise a single
pot, one step procedure and does not require recovery of PCl3
from the reaction mass (Scheme-I). And the synthesis of its
chalcogenides by reacting 3,9-bis[2,4-di(tert-butyl phenoxy]-
2,4,8,10-teraoxa-3,9-diphosphaspiro[5.5]undecane with
elemental sulphur, selenium in toluene (Scheme-II)4,5. Tungsten
pentacarbonyl complex (5) was prepared by reacting (2) with
W(CO)5CH3CN in THF at 20-25 ºC (Scheme-III) and purified
by recrystalisation with diethylether. The structure of the
products 1-5 were deduced from their IR, 1H, 13C and 31P NMR
spectra. The mass spectra of these compounds (Table-5)

4558 Rani et al.
Asian J. Chem.
TABLE-4
13C NMR SPECTRUM OF COMPOUND (1-5)
Compound No.
13C NMR data
1
2
3
4
5
δ30.16, 31.61, 34.91, 37.04, 62.71, 118.61, 124.42, 139.13, 149.14.
δ 31.39, 34.83, 36.35, 69.79, 118.64, 124.80, 138.50, 146.98, 147.83.
δ 30.46, 31.59, 34.89, 36.71, 61.51, 119.54, 124.70,139.24,146.37, 148.89.
δ 31.42, 34.77, 36.89, 69.13, 119.96, 124.81, 139.34, 147.93.
δ 31.38, 34.93, 36.09, 65.94, 119.79, 123.81, 125.29, 139.48, 147.96, 194.01.
t-Bu
t-Bu
displayed molecular ion peaks at the appropriate m/z values.
OH
OH
t-Bu
PCl , Et N, Toluene
The infrared spectra (Table-6) of 3,9-bis[2,4-di(tert-butyl
phenoxy]-2,4,8,10-teraoxa-3λ5,9λ5-diphosphaspiro[5.5]-
undecane-3,9-diselone (4) shows a strong and sharp absorption
3
3
HO
OH
+
O
O
O
O
100-110 ºC
t-Bu
O
P
P
O
t-Bu
OH
t-Bu
band at 588.2 cm-1 which has been assigned to -P=Se stretching
(1)
absorption vibrations. The proton magnetic resonance spectrum
of compound (4) shows two multiplets at δ 4.303 and 4.558
for eight methylene protons, two singlets for tert. butyl protons
at δ 1.315, 1.421 and all the aromatic protons in position at δ
7.141-7.414 as multiplet for 6H. The phosphorus magnetic
resonance spectrum of compound (4) shows a doublet at δ
60.422 with a coupling constant of 1034.122 Hz due to
phosphorous selenium coupling. In the 13C NMR spectrum of
compound (4) shows eight carbon, which are well in accordance
to the proposed structure. and the peaks at δ 31.42, 34.77,
36.89, 69.13, 119.96, 124.81, 139.34, 147.93. Mass spectra
of compound (4) shows molecular ion peak 763 (M + 1) that
is in agreement with the formula and structure of (4).
Scheme-I: Synthesis of 3,9-bis[2,4-di(tert-butyl phenoxy]-2,4,8,10-
teraoxa-3,9-diphosphaspiro[5.5]undecane
t-Bu
t-Bu
O
O
O
O
t-Bu
t-Bu
DMSO, CH Cl
t-Bu
O
P
P
O
t-Bu
2
-80 ºC, 2 h
2
O
O
t-Bu
t-Bu
(2)
O
O
O
O
t-Bu
O
P
P
O
t-Bu
S, Se, Toluene
110 ºC, 14-24 h
110 ºC, 3-5 h
O
O
O
t-Bu
O
P
P
O
t-Bu
(1)
X
O
X
X = S (3), Se (4)
Scheme-II: Synthesis of calcogenides of 3,9-bis[2,4-di(tert-butyl
phenoxy]-2,4,8,10-teraoxa-3,9-diphosphaspiro[5.5]undecane
Conclusion
t-Bu
t-Bu
t-Bu
t-Bu
In summary, a simple and cost effective method is deve-
loped for the preparation of 3,9-bis[2,4-di(tert-butyl phenoxy]-
2,4,8,10-teraoxa-3,9-diphosphaspiro[5.5]undecane, which is
used as stablizer and antioxidant in polymers. And its chalco-
genides having a great stability and antioxidant property have
been prepared in good to excellent yields.
W(CO) CH CN, THF
5
3
O
O
O
O
O
O
O
O
20-25 , 2
20-25 ºCºC, 6-82 hh
P
P
O
t-Bu
t-Bu
O
t-Bu
O
P
P
O
t-Bu
(OC)5
W
W(CO)5
( )
1
( )
5
Scheme-III: Synthesis of tungsten complex of 3,9-bis[2,4-di(tert-butyl
phenoxy]-2,4,8,10-teraoxa-3,9-diphosphaspiro[5.5]undecane
TABLE-5
ACKNOWLEDGEMENTS
MASS OF COMPOUND (1-5)
S. No.
(M + 1)
605
S. No.
(M + 1)
763
The authors (Manju Rani andArif Ali Khan) are thankful
to CSIR, New Delhi for financial assistance.
1
2
3
4
5
–
637
1251
–
669
REFERENCES
1. G. Marlin, US Patent 5917076 (1999).
2. S. Costanzi, R. Farris and D. Girelli, Polym. Degrad. Stab.,73, 425
(2001).
TABLE-6
INFRARED SPECTRUM OF COMPOUND (1-5)
Compound No.
Absorption peaks (cm-1)
968, 1145.6 (P-O-Caromatic
1251.1 (P=O)
3. J.D. Spivack, US Patent 4692539 (1987).
4. A.A. Khan, C. Wismach, P.G. Jones and R. Streubel, Dalton Trans.,
2483 (2003).
)
1
2
3
4
5
5. A.A. Khan, C. Neumann, C. Wismach, P.G. Jones and R. Streubel, J.
Organomet. Chem., 682, 212 (2003).
671.2 (P=S)
588.2 (P=Se)
1718.5, 1944.1 and 2083.0 (CO)