Rapid and Efficient Synthesis of ω-Alkylenediphosphoric Acids from Phosphorus Oxychloride

Article abstract of DOI:10.1155/2016/8046893

The aim of this investigation was to develop an efficient, rapid, and selective method for the synthesis of ω-alkylenediphosphoric acids (HO)₂(O)P-O-(CH₂)_n-O-P(O)(OH)₂ from reaction of several diols with phosphorus oxychloride. The reaction was investigated using three methodologies: (i) presence of a base, (ii) classical heating, and (iii) use of microwave irradiation. Influence of reaction temperature and molar ratio of reagents, as well as the nature of the solvent, was studied using these three different methods.

Full text of DOI:10.1155/2016/8046893

Hindawi Publishing Corporation
Journal of Chemistry
Volume 2016, Article ID 8046893, 7 pages
http://dx.doi.org/10.1155/2016/8046893
Research Article
Rapid and Efficient Synthesis of ꢀ-Alkylenediphosphoric Acids
from Phosphorus Oxychloride
Dalila Meziane,1 Abdelhamid Elias,1 and Erwann Guénin2
1
´
´
´
Departement de Chimie, Faculte des Sciences, Universite Mouloud Mammeri, BP 17 RP, 15000 Tizi Ouzou, Algeria
2
´
´
UFR SMBH, Universite Paris 13, Sorbonne Paris Cite, 74 rue Marcel Cachin, 93017 Bobigny, France
Correspondence should be addressed to Erwann Gue´nin; guenin@univ-paris13.fr
Received 2 November 2015; Revised 16 December 2015; Accepted 11 January 2016
Academic Editor: Marijan Kocevar
Copyright © 2016 Dalila Meziane et al. is is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
e aim of this investigation was to develop an efficient, rapid, and selective method for the synthesis of ꢀ-alkylenediphosphoric
acids (HO) (O)P-O-(CH )ꢀ-O-P(O)(OH) from reaction of several diols with phosphorus oxychloride. e reaction was
2
2
2
investigated using three methodologies: (i) presence of a base, (ii) classical heating, and (iii) use of microwave irradiation. Influence
of reaction temperature and molar ratio of reagents, as well as the nature of the solvent, was studied using these three different
methods.
1. Introduction
step is the hydrolysis of the phosphorodichloridate formed
in the first step. By a similar way, the reaction of diols with
Alkylphosphates, also called phosphate esters, have found
numerous applications over the years mainly in various
industrial processes, such as flame retardants, plasticizing
agents, lubricants, surfactants, reagents in solvent extraction
of heavy metal ions, and corrosion inhibitors [1–9].
POCl may be represented as shown in Scheme 1. By the same
3
mechanism, two molecules of POCl may react with the same
3
molecule of diol to form diphosphorotetrachloridate, which
is then hydrolyzed in a second step, thus forming the desired
alkylenediphosphoric acids: (HO) (O)P-O-(CH ) -O-P(O)-
2
2 ꢀ
Organic phosphates are generally synthesized from con-
densation of alcohol with several phosphorus substances:
P O , POCl , PCl , PCl , and H PO [10–14]. In general, the
(OH) .
2
In fact, the reaction of a diol (as in case of an alcohol)
with phosphorus oxychloride leads to a complex mixture
of mono(di)alkylphosphoric acids, trialkylphosphate, and
polyphosphoric acids. e proportion of each compound
depends on the reaction conditions [17]. e lack of selectiv-
ity is a major inconvenience for this synthetic route, since the
composition is hardly controlled giving generally low yields
of the desired product which is difficult to separate from the
crude mixture. Another problem of this reaction, mainly in
case of alcohols or diols with long hydrocarbon chains, is their
lower reactivity compared to the alcohols with shorter alkyl
chain. At classical conditions, this low reactivity induces the
need of long reaction times and high temperatures (>100∘C)
[11, 18].
2
5
3
3
5
3
4
products are mixtures of mono-, di-, and triesters, together
with some byproducts and unreacted alcohols [15]. is
phenomenon is of course enhanced when reacting diols
or polyols. Nevertheless, selective formation of monoesters
could be obtained by reacting excess of the phosphorus
species, but this involves more difficult purification steps.
Among the different phosphorus reactants, phospho-
rus oxychloride appears as a good compromise to obtain
monoalkylphosphates as it is less reactive than phosphorus
chlorides. e synthesis of alkylphosphoric acids through the
reaction of phosphorus oxychloride with alcohols involves
two steps. e first step consists in a nucleophilic attack of the
alcohol at the P center of POCl , in order to yield the forma-
In this paper, we report reactions of phosphorus oxy-
chloride with several diols with varying hydrocarbon chain
length. In order to try to control the selectivity of the reaction,
3
tion of an intermediate compound: phosphorodichloridate by
a bimolecular mechanism (termed SN P) [16]. e second
2

2
Journal of Chemistry
O
P
Cl
Cl
−
−
H
−
−
O
P
O
P
Cl
OH
−
Cl
Cl
HO
Cl
Cl
−HCl
−
−
⊖
( )
⊕
O
O
HO
HO
+
n
−
Cl
−
( )
( )
Step 1
n
n
O
P
−HCl
Cl
Cl
Cl
O
Cl
O
O
O
O
O
O
H2O
O
( )
( )
P
P
P
P
n
n HO
Cl
HO
OH
Step 2
Cl
Cl
OH
Example of possible byproducts
O
O
P
O
HO
HO
( )
P
n
O
O
OH
OH
O
O
( )
( )
n
n
( )
( )
n
n
HO
HO
O
O
O
O
O
O
O
O
O
( )
∗
( )
P
P
( )
∗
∗
P
( )
P
n
∗
n
nHO
O
O
O
n O
O
O
OH
OH
m
( )
n
O
m
Scheme 1: General route for the formation of ꢀ-alkylenediphosphoric acids from phosphorus oxychloride.
to obtain monoalkyl diphosphoric esters, and improve the
synthetic process, we investigated three different approaches
for this reaction: firstly the reactions were activated by classi-
cal heating and then by the use of triethylamine at low tem-
perature and finally the reactions were run under microwave
irradiation.
from methanol/ethyl acetate (1/4). e final product corre-
sponds to the monoesterified phosphoric acids. However, it is
worth mentioning that under whatever conditions used it was
never obtained in pure form. e maximum purity (calcu-
lated by 31P NMR) that corresponds to optimized conditions
was 95%. e remaining 5% impurities were attributed to the
formation of at least one dialkyl phosphoric acid. Attempts to
realize the reaction with a decreased or stoechiometric ratio
2. Results and Discussion
of POCl /Diol (ꢁ ꢂ = or ꢁ ꢂ =) were unsuccessful; it resulted
3
2.1. Method 1: Conventional ermal Activation. Using con-
ventional heating, the reactions were carried out according to
a slightly modified procedure with respect to the one reported
in product mixtures only, which were quite difficult to sepa-
rate or even to identify. Using the optimized conditions, pure
products were obtained, yields ranging from 65% to 85%,
depending on the diols nature (Table 1). Although appreciable
yields and purity are obtained, this method presents some
drawback, such as length of reaction (several hours) and need
for similar products [18]. A large excess of POCl versus diol
3
was used (ꢁ ꢂ =) and refluxed with the diol for several hours
in toluene. e evolution of the reaction was followed by
1
NMR; the 31P { } spectrum showed the appearance of a new
H
of high reaction temperatures and excess of POCl .
3
peak around 5-6 ppm which corresponds to the monoalkyl
phosphorodichloridate intermediates (POCl signal appears
2.2. Method 2: Activation by a Base (NEt3). Due to the low
3
around 4.5 ppm (Figure 1(a))). During the hydrolysis step, we
noted some progressive decrease of the peak area, at 6 ppm,
in favor of a new one, around 0 ppm, corresponding to the
desired products. e other peaks, observed with a little con-
tribution, correspond to byproducts due to a partial hydro-
nucleophilicity of diols their reaction with POCl is slow.
3
In the literature, bases are frequently used to activate the
reaction of hydroxyl compounds with phosphorus oxychlo-
ride [17]. In this study, we tested the activating role of
triethylamine (NEt ) in the reaction of diols with POCl .
3
3
lysis of POCl and formation of anhydride (Figure 1(b)). e
NEt has a double character: nucleophilic and basic, so it
3
3
desired product was then isolated by means of precipitation
can readily react with POCl to form an activated product
3

Journal of Chemistry
3
O
O
O
O
O
O
( )
O
O
nCl
P
P
Cl
Cl
OH nHO
( )
P
P
HO
OH
Cl
10
0
−10
−20
15
10
5
0
−5
−10
−15
(a)
(b)
Figure 1: 31P NMR spectra of the reaction mixtures, obtained during the two-step synthesis. (a) Step 1, (b) step 2 (Method 1).
O
P
Cl
O
P
Cl
Et ⊕
⊖
Cl
−
Cl
Et
N
+
Cl
Et
Et
+
Cl
N
Et
Et
−
−
−
−
HO
OH
( )
n
−
Et
Et
N
O
P
H
⊕
⊖
−
Cl
Cl
Et
O
P
⊖
Cl
⊕
O
Et3HNCl
HO
+
+
Cl
−
O
HO
( )
−
( )
n
n
Cl
NEt3/POCl3
O
O
O
P
O
⊕
⊖
( )
P
+
Et3HNCl
n
Cl
Cl
Cl
Cl
Scheme 2: General route to the formation of ꢀ-alkylenediphosphoric acids from phosphorus oxychloride, using triethylamine.
(Scheme 2). is positively charged intermediate is more
end of the process, the major product showed a signal
around 5-6 ppm (Figure 2(a)). Afer a hydrolysis step, these
intermediates mainly afford the desired product and other
nonidentified byproducts, probably resulting from polyester-
reactive than the POCl . It is then easily attacked by the
3
hydroxyl group of the diols. e reaction is even exothermic
and was conducted at low temperature (−15∘C), implying
some handling caution. In this reaction, the amine plays a
second role which consists in the fixation of the formed HCl
ification. In this procedure, an excess of POCl was also
3
necessary to lessen double or even triple attack of the diols,
and provides the corresponding chlorhydrate (NEt , HCl).
on the same POCl molecule, allowing for the formation of
3
3
e precipitation of the chlorhydrate, in an adequate solvent,
displaces the reaction-equilibrium towards the formation of
the phosphonic ester (Scheme 2).
di- or trialkylphosphates compounds. Nevertheless use of 4
equivalents of POCl did not completely avoid the formation
3
of these byproducts, since the desired product was never
obtained in pure form (maximum purity obtained was 90%).
e reactions of POCl with diols, according to this
3
pathway, were followed by NMR. e 31P { } NMR spectra
1
One must also note that an increase in POCl did not result
H
3
in any increase of purity either.
showed the formation of different intermediates, but at the

4
Journal of Chemistry
Table 1: Reaction conditions and results of the synthesized products
vessel by controlling power delivery during the reaction.
Under microwave irradiation, the final and intermediate
with the different methods.
products emerging from the reaction of diols with POCl
3
Yield ꢃ (%)
were identical to those which were formed using conven-
tional heating. ese products essentially consist in the
diphosphorotetrachloridate formed in the first step (Scheme
2) and the alkylenediphosphoric acids (HO) (O)P-O(CH ) -
C
C
C
Diols →
6
9
12
Method 1
70a
65b
65
65a
62b
68
85a
75b
72
∘
ꢄ ꢂ 110 C, ꢁ ꢂ =, ꢅꢁ ꢂ 8–10 h,
2
2 ꢀ
solvent: toluene
O-P(O)-(OH) obtained afer the hydrolysis step (Figure 3).
2
e results are satisfactory (65–72%) and comparable
to those obtained with the previous methods (1 and 2)
(Table 1). However, this time the purity was better as no traces
of di- or polyalkylphosphate were observed. Another asset
of this methodology was that the amount of phosphorus
oxychloride was reduced by a factor 2, from 4 to 2 equiv.,
and the reaction time of the diphosphorotetrachloridate
formation was shortened to 2 minutes, instead of more than
8 hours when using thermal heating. is method, compared
to method 2, has also the advantage of being catalyst-
free.
Method 2
∘
ꢂ
ꢄ ꢂ −15 C → 20∘C, ꢁ ꢂ =, ꢁ ꢂ =,
ꢅꢁ ꢂ 2 h,
solvents: THF (C ) or diethyl ether
12
(C and C )
6
9
Method 3
∘
ꢄ
ꢂ 85 C, ꢁ ꢂ 2, ꢅꢁ ꢂ 2 min,
Max
ꢆ ꢂ 100 W, solvent: acetonitrile
ꢂ
ꢃꢁ: reaction time (step 1), ꢄ: molar ratio POCl /diol, ꢄ : molar ratio triethy-
3
lamine/diol, C : hexane-1,6-diol, C : nonane-1,9-diol, and C : dodecane-
6
9
12
1,12-diol.
a,bProducts were not obtained in pure form (maximum purity a: 95%, b:
90%).
Polar solvents like acetonitrile seem to be useful for
the reaction under microwave irradiation. When toluene
was used, only traces of products are detected even under
much harsher conditions (ꢇ ꢂ 150 W, ꢅ ꢂ =0 min, and
ꢁ ꢂ =). is is due to the nonpolar nature of toluene, as
only polar molecules selectively absorb microwaves while
nonpolar molecules are known to be inert to microwave
dielectric losses [20, 23]. Indeed, the heat generated by the
reactants rotating molecules, when submitted to microwave
irradiation, dissipated in this solvent through convection
mechanisms. Using the conditions cited above, the resulting
temperature (ꢄmax = 40∘C) is too low to activate the reaction.
Tests, carried out without solvent, generated a rapid and
uncontrollable increase of the temperature in the reaction
During the reaction, an excess of NEt was also needed
3
in order to scavenge the totality of the formed HCl and thus
avoid the formation of chloroalkanes as byproducts. Use of
low molar ratios (2-3 equivalents) of POCl and/or NEt gave
3
3
quite complex mixtures. Only small quantities of the desired
product were formed and isolated in this case. Different
solvents were evaluated for the reaction (dichloromethane,
tetrahydrofuran, and diethyl ether). e best results were
obtained with diethyl ether in case of C and C diols, while
6
9
in case of C the best results were obtained with THF. e
12
success of the reactions with these solvents is probably due
mixture, especially when no excess of POCl (ꢁ ꢂ 2) was
3
to the precipitation of the chlorhydrate salt (NEt , HCl).
3
used. Yields in solvent-free conditions did not exceed 50%,
even under the use of a large excess of the reagent (ꢁ ꢂ =).
e optimal conditions and the corresponding yields for
the 3 methodologies are summarized in Table 1.
When dichloromethane, in which triethylammonium salt is
known to be partially soluble, was used, only low quantity of
product was extracted. Using the optimized conditions, yields
lie in the range 62%–75%. ese are comparable to those
obtained with the first method yet the products exhibit less
purity (reaching its maximum at 90%). However, this second
method presents two advantages as compared to thermal
activation: that is a decrease of the reaction time (2 h versus
10 h) and the absence of any heating, since everything works
at ambient temperature, as compared to the usual 110∘C. e
3. Experimental Section
3.1. Reagents and Solvents. Phosphorus oxychloride (99%),
triethylamine (>99%), and diols hexane-1,6-diol (99%),
nonane-1,9-diol (98%), and dodecane-1,12-diol (99%) were
purchased from Sigma-Aldrich. Diols were used without
further purification. Phosphorus oxychloride and triethy-
lamine were distilled before use. All solvents were pur-
chased from Carlo Erba-SDS and also distilled before use.
Dichloromethane, acetonitrile, and ethyl acetate were dis-
tilled over P O . Methanol, ethanol, diethyl ether, and toluene
major inconvenience of this procedure lies in the need of
ꢂ
reagents, POCl (ꢁ ꢂ =) and amine (ꢁ ꢂ =), in excess.
3
2.3. Method 3: Activation by Microwave Irradiation. Micro-
wave offers a number of advantages over conventional heat-
ing, such as fast-and-homogeneous noncontact heating [19].
Moreover, use of microwaves offers drastically reduced pro-
cessing time. at could, in fact, account for its spreading
during the last three decades, in several areas of chemistry
[20]. In particular, this methodology had a positive impact
on phosphorus chemistry as well as on several organophos-
phorus reactions that has benefited from the use of micro-
waves [21, 22]. We thus apply it to the synthesis of ꢀ-alkyl-
enediphosphoric acids. e reaction was conducted in open
2
5
were distilled over sodium. e THF was likewise distilled
over sodium in presence of benzophenone.
3.2. Instruments. NMR spectra were recorded with a VAR-
IAN Unity Inova 500 MHz (13C: 125.9, 1H: 500.6 MHz) or a
VARIAN Gemini 200 MHz (31P: 80.9 MHz) spectrometer in
CD OD. Chemical shifs are reported in parts per million
3
(ppm) on the ꢈ scale. e residual solvent peak (CD OH)
3
1
was used as a reference for H NMR (3.31 ppm) and 13C

Journal of Chemistry
5
O
O
O
O
( )
P
P
Cl
nCl
Cl
Cl
O
O
O
O
( )
P
P
OH nHO
HO
OH
10
0
−10
10
0
(ppm)
(ppm)
(a)
(b)
Figure 2: 31P NMR spectra of the reaction mixtures obtained during the two-step synthesis. (a) Before the hydrolysis (step 1). (b) During
hydrolysis step 2 (Method 2).
O
O
O
O
n Cl
( )
O
O
P
P
O
O
Cl
Cl
( )
Cl
P
P
OH nHO
HO
OH
5
0
−5
−10
−15
10
5
0
−5
−10
−15
(a)
(b)
Figure 3: 31P NMR spectra of 1,12-Bis[(dihydroxyphosphinyl)oxy]dodecane obtained with method 3. (a) Crude mixture obtained during
step 1. (b) Crude mixture obtained afer hydrolysis step 2 and before purification.
NMR (49.0 ppm). 31P NMR spectra were recorded using
phosphoric acid (85%) as the external reference. Data are
reported as follows: s = singlet, d = doublet, t = triplet,
q = quartet, dt = doublet of triplet, and m = multiplet.
Coupling constants are given in Hz. e FTIR spectra were
recorded using a Nicolet FTIR 380 spectrophotometer and
measured in wavenumbers (cm−1). e mass spectra were
run on a MALDI-TOF mass spectrometer (Biflex IV, Bruker
Daltonique) with 2,5-dihydroxybenzoic acid as matrix.
All melting points are recorded using a Stuart SMP3
melting point apparatus and are uncorrected.
3.3. General Procedure for the Conventional Heating Synthesis
(Method 1). e following procedure was adapted from
synthesis reported for similar compounds [18]. Phosphorus
oxychloride (30.66 g; 200 mmol) and the diol (5.9; 8.01; 10.11 g
(resp., for ꢉ ꢂ =, 9, or 12); 50 mmol) were added under
argon successively to a round bottom flask containing 120 mL
of toluene. e mixture was refluxed for 8 to 10 h under
magnetic stirring. e solution was then concentrated with a
rotary evaporator and the viscous residue was coevaporated
twice with 100 mL of toluene.
In the second step the obtained residue was hydrolyzed
by 100 mL of cold water. Distilled water was added care-
fully to the residue, previously cooled (5–10∘C). en the
All experiments under microwave irradiations were run
in open vessel, using a CEM-Discover microwave apparatus.

6
Journal of Chemistry
solution was warmed down to 90∘C and stirred for 2 to 3
hours. During the hydrolysis, a white precipitate appeared
and was isolated afer water filtration. e obtained white
solid was dissolved in 100 mL of ethanol which was then
evaporated. is operation was repeated twice in order to
remove the remaining HCl. e residue was finally dissolved
in methanol/ethyl acetate (1/4) (v/v) and the solution was lef
to precipitate overnight (in a freezer for compounds I and
II, at r.t for compound III). e white powder was filtered,
washed with diethyl ether, and dried in desiccators.
= 5.8 Hz, POCH ); 31.6 (d, 3ꢊP-C = 5.8 Hz, POCH CH ); 30.3
2
2
2
(POCH CH CH CH ); 30.6 (POCH CH CH CH CH );
2
2
2
2
2
2
2
2
2
26.7 (POCH CH CH ). Elementary Analysis C H O P
2
2
2
9
22
8
2
calcld C: 33.8; H: 6.9; O: 40.0; P: 19.3 found C: 33.2; H: 7.2; O:
39.9; P: 19.7.
3.8. 1,12-Bis[(dihydroxyphosphinyl)oxy]dodecane (Compound
1
III). mp = 114∘C. 31P { } NMR ꢈ: 0.9 1H NMR ꢈ:
H
3
3
3.96 (dt, 4H,
ꢊ
=
ꢊ
= 6.7 Hz, POCH ); 1.66
H-H
P-H
2
(m, 4H, POCH CH ); 1.40 (m, 4H, POCH CH CH );
2
2
2
2
2
1.32 (m, 12H, POCH CH CH CH CH CH ). 13C {
}
1
H
2
2
2
2
2
2
2
3
3.4. General Procedure for the Synthesis Using Triethylamine
(Method 2). In a 150 mL tricol flask equipped with a reflux
condenser, a thermometer, and an addition funnel a solution
of phosphorus oxychloride (9.2 g; 60 mmol) was mixed with
30 mL of solvent (diethyl ether, dichloromethane, or tetrahy-
drofuran (THF)). A solution of diol (15 mmol) and triethy-
lamine (6.08 g; 60 mmol) was then introduced dropwise. e
reaction being very exothermic, the flask was placed in a mix-
ture of liquid nitrogen and ethanol to keep the temperature
at approximately −15∘C, during the reagent addition. Afer
completion of the addition, the mixture was stirred at room
temperature (20∘C) for 2 hours. 20 mL of distilled water was
then added to the reaction mixture and lef under magnetic
stirring, at room temperature, overnight. e mixture was
then concentrated with a rotary evaporator before 20 mL
of cold water was finally added to the viscous residue and
the yellow organic layer removed from the aqueous phase.
e desired product was isolated by recrystallization from
methanol/ethyl acetate (1/4) (v/v).
NMR ꢈ: 67.9 (d,
ꢊ
= 5.8 Hz, POCH ); 31.6 (d,
ꢊ
P-C
2
P-C
= 5.9 Hz, POCH CH ); 30.4 (POCH CH CH CH ); 30.7
2
2
2
2
2
2
(POCH CH CH CH CH CH ); 26.3 (POCH CH CH ). IR
2
2
2
2
2
2
2
2
2
(KBr), (cm−1): 2919, 2852, 1474 (C-H), 2360 (PO-H), 1234,
1095, 1038 (P=O) and (C-O), 1012, 937 (P-O). M/z (MH+):
363.25; calcld: 363.13. Elementary Analysis C H O P cal-
12 28
8
2
cld C: 39.8; H: 7.8; O: 35.3; P: 17.1 found C: 39.7; H: 8.0; O: 35.0;
P: 16.9.
4. Conclusion
In this work we evaluated three different methodologies to
obtain various ꢀ-alkylenediphosphoric acids from conden-
sation of phosphorus oxychloride onto diols with varying
chain length. ree methodologies were studied: (i) the
conventional heating of both reactants in organic solvent,
(ii) the reaction under basic activation at low temperature,
and (iii) the use of short microwave heating. Afer opti-
mization, all methodologies permit obtaining the desired
alkylenediphosphoric acids (HO) (O)P-O-(CH ) -O-P(O)-
2
2 ꢀ
(OH) as main product, but only the microwave assisted one
2
3.5. General Procedure for the Synthesis under Microwave
Irradiation (Method 3). Phosphorus oxychloride (3.36 g;
22 mmol) was placed in a 100 mL flask, equipped with a
reflux condenser and closed by a calcium chloride tube with
a diol (10 mmol) and acetonitrile (15 mL) as solvent. e
mixture was then irradiated at 100 W for 2 min, under vig-
orous stirring. e mixture initially heterogeneous became
homogenous within a few seconds of irradiation. At the end
of the irradiation process, the mixture is poured into a flask
containing 30 mL of cold distilled water. e hydrolysis and
the purification procedures are similar to those described in
method 1.
allows for the obtaining of pure products without presence
of any traces of polyalkylation byproducts. Moreover, this
later methodology permits drastically decreasing the reaction
time without using excess of either reactant or any catalyst. It
thus appears as an interesting way of synthesizing selectively
monoalkylphosphate. In addition, due to relatively friendly
conditions, it could be further applied to more sensible
substrates.
Conflict of Interests
e authors declare that there is no conflict of interests
regarding the publication of this paper.
3.6. (1,6-Bis[(dihydroxyphosphinyl)oxy]hexane) (Compound
1
I). mp = 96∘C. 31P { } NMR ꢈ: 0.2. 1H NMR ꢈ: 3.97 (dt, 4H,
H
References
3
ꢊ
= 3ꢊ = 6.5 Hz, POCH ); 1.68 (m, 4H, POCH CH );
H-H
P-H
2
2
2
1.45 (m, 4H, POCH CH CH ). 13C { } NMR ꢈ: 67.7 (d, 2ꢊ
1
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H
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2
2
P-C
= 5.8 Hz, POCH ); 31.4 (d, 3ꢊP-C = 5.8 Hz, POCH CH ); 26.3
2
2
2
(POCH CH CH ). Elementary Analysis C H O P calcld
C: 25.9; H: 5.8; O: 46.0; P: 22.3 found C: 26.2; H: 5.7; O: 46.4;
2
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2
6
16
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II). mp = 109∘C. 31P { } NMR ꢈ: 0.6. H NMR ꢈ: 3.96
1
1
H
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3
(dt, 4H,
ꢊ
=
ꢊ
= 6.7 Hz, POCH ); 1.67 (m, 4H,
POCH CHH)-;H1.41 (m, 4H, POCH CH CH ); 1.32 (m, 8H,
P-H
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POCH CH CH CH CH ). 13C { } NMR ꢈ: 67.9 (d, ꢊ
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H
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P-C

Journal of Chemistry
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