Conversions of 2-phenyl-1,3,2-dioxaphospholane under the action of hydrogen chloride

Article abstract of DOI:10.1023/A:1026356902889

The reaction of 2-phenyl-1,3,2-dioxaphospholane with HCl gives a mixture of phenylphosphinic acid, bis(2-chloroethyl) phenylphosphonate, and phenylphosphine; therewith, intermediate oligomeric phosphonites, hydrophosphoryl compounds, and phosphoranes were detected. Thermal treatment of the reaction mixture results in formation of ethylene phenylphosphonate and (2-chloroethyl)phenylphosphinate.

Full text of DOI:10.1023/A:1026356902889

Russian Journal of General Chemistry, Vol. 73, No. 6, 2003, pp. 928 932. Translated from Zhurnal Obshchei Khimii, Vol. 73, No. 6, 2003,
pp. 981 985.
Original Russian Text Copyright
2003 by Lazarev, Bredikhina, Bredikhin.
Conversions of 2-Phenyl-1,3,2-dioxaphospholane
Under the Action of Hydrogen Chloride
S. N. Lazarev, Z. A. Bredikhina, and A. A. Bredikhin
Arbuzov Institute of Organic and Physical Chemistry, Kazan Research Center,
Russian Academy of Sciences, Kazan, Tatarstan, Russia
Received May 31, 2001
Abstract The reaction of 2-phenyl-1,3,2-dioxaphospholane with HCl gives a mixture of phenylphosphinic
acid, bis(2-chloroethyl) phenylphosphonate, and phenylphosphine; therewith, intermediate oligomeric phos-
phonites, hydrophosphoryl compounds, and phosphoranes were detected. Thermal treatment of the reaction
mixture results in formation of ethylene phenylphosphonate and (2-chloroethyl)phenylphosphinate.
Together with other heterophosphacyclanes, 1,3,2-
dioxaphospholanes are widely used in organic syn-
thesis [1]. Recently we proposed a method for prepar-
ing 4-chloromethyl-substituted 1,3,2-dioxaphospha-
cyclanes by reaction of geminal phosphorus dichlo-
yield of hydrophosphoryl compound II gave the
referees grounds to include this reaction into the list
of promising methods of synthesis of alkylene phos-
phonohaloidites [7]. The controversy in the available
data prompted us to study in more detail the reaction
of phosphonite I with HCl by 31P and C NMR spec-
troscopy.
13
rides RP(X)Cl (X = lone electron pair, R = Cl; X =
2
O, R = Me, Ph, OEt, OMent, NEt , Cl) with glycidol
2
[
2 4]. At the same time, it was found that 2-methyl-
We reacted compound I with excess HCl by the
and 2-phenyl-4-chloromethyl-1,3,2-dioxaphospho-
31
procedure described in [6]. The P NMR spectrum of
lanes (X = lone electron pair; R = Me, Ph) immedi-
ately they form undergo further transformations
leading to hydrophosphoryl compounds, cyclic and
acyclic phosphonates, and primary phosphines [4].
We presumed that all further transformations of
primary cyclic phosphonites are induced by the free
HCl present in the reaction mixture.
the crude reaction mixture contained four signals: a
1
triplet at
123.36 ppm , J 198 Hz (PhPH2,
P
PH
26% of the total integral intensity), a broadened
singlet at 20.09 ppm without direct P H coupling
P
constants [ 50%, bis(2-chloroethyl) phenylphospho-
nate (III); the assignement was conformed by the
independent synthesis of this compound from
PhP(O)Cl and 2-chloroethanol], and a doublet at
2
P
1,3,2-Dioxaphospholanes are commonly prepared
1
2
8.33 ppm of PhPH(O)OR ( J
570 Hz, 22%),
PH
by reaction of geminal disubstituted phosphorus
and a signal of 2-phenyl-1,3,2-dioxaphospholan-2-one
37.14 ppm (2%). This spectrum always
derivatives RP(X)Y (X = lone electron pair, O, S,
2
(IV) at
P
etc.; Y = Cl, NAlk , OMe, etc.) with vicinal diols.
2
reproduced on repeated experiments (see figure,
Richter [5] reported the formation in similar reactions
with dichlorophosphines of 1,3,2-dioxaphospholan-2-
ones and primary phosphines along with 1,2,3-dioxa-
phospholanes [5]. The resulting product ratios were
strongly dependent on the amount of base in the reac-
tion mixture. However, no explanation of the reasons
for and ways of formation of these products was gives
in that work. In our opinion, the unexpected pro-
ducts are formed under the action of HCl on the start-
ing cyclic phosponites.
spectrum d).
The 31P NMR spectrum of the reaction mixture
shortly after HCl had began to pass through the solu-
tion of the starting compound (see figure, spectrum a)
contained only two signals of roughly equal intensity
( P 162.4 and 157.5 ppm) and a weak signal at
60.3 ppm (see figure, spectrum b). The first and third
P
1
signals belong respectively compound I and its
dimmer (the tendency of phosphonites for dimeriza-
tion is well known [8]). The second signal probably
belongs to a cyclic oligomer of dioxaphospholane I.
Evidence for this assumption comes from the observa-
tion of Mukaiyama et al. [6] that after addition to the
cyclic phosphonite of a catalytic amount of sulfuric
acid produces thickening of the mixture.
At the same time, Mukaiyama et al. [6], who
studied direct reaction of HCl with 2-phenyl-1,3,2-di-
oxaphospholane (ethylene phenylphosphonite) (I),
stated that the single reaction product is (2-chloro-
ethyl)phenylphosphinate (II). The fairly high (>49%)
1
070-3632/03/7306-0928$25.00 2003 MAIK Nauka/Interperiodica

COVERSIONS OF 2-PHENYL-1,3,2-DIOXAPHOSPHOLANE
929
(
a)
1
75
100 75
59
25
0
25
50 75 100 125
(
b)
1
75
125 100 75
50
25
75 100 125
(
c)
1
75 150
125 100 75
50 25
25
50 75
100 125
(
d)
175 150
125 100 75
50 25
25 50
75
125
(
e)
1
75 150 125 100 75
50 25
0
50
0
75 100 125
(
f)
2
5
50
0
75
175 150 125 100 75
50 25
(
g)
1
75 150 125 100 75
50 25
25
P, ppm
3
1
P NMR spectra of 2-phenyl-1,3,2-dioxaphospholane (I), its reaction mixtures with HCl, and reaction products. (a) Com-
pound I, (b) reaction mixture after passing of the first portion of HCl, (c) reaction mixture after passing of 0.9 equiv of HCl,
d) the latter mixture kept for 1.5 days at room temperature, (e) final reaction mixture after passing of excess HCl, (f) first
(
fraction obtained by distillation of the final reaction mixture, and (g) second fraction obtained by distillation of the final
reaction mixture.
On further passing of HCl, the signals at
162.4
signals and, in addition, a weak singlet appeared
P
and 157.5 ppm decreased, at first the former signal
belonging to cyclic phosphonate IV. Therewith, the
faster. At the same time, signals of a hydrophosphoryl
signal at 157.5 ppm appreciably decreased, whereas
1
P
compound ( P 24.5 ppm, J
557 Hz), acyclic
PH
those of the hydrophosphoryl compounds and acyclic
phosphonate III slightly increased (see figure, spec-
trum d). Barboting into the intermediate mixture of
excess hydrogen chloride at room temperature led to
the above-described 31P NMR spectrum (see figure,
spectrum e).
phosphonate III, and PhPH , as well as signal at
2
P
1
9 ppm, belonging to 5-phenyl-1,4,6,9-tetraoxa-5-
phosphaspiro[4.4]nonane ( P 20 ppm [9]) appeared
see figure, spectrum c). With deficient HCl, the 31
(
P
NMR spectrum of the reaction mixture kept for
.5 days at room temperature preserved all the above
1
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 6 2003

9
30
LAZAREV et al.
Distillation of the final crude mixture gave two
liquid fractions (the volatile phenylphosphine was
collected separately into a special cooled trap). The
The appearance of cyclic phosponate IV in the
crude reaction mixture might be assigned to oxidation
of phosphonite I with atmospheric oxygen, since the
ability of the latter to oxidize acyclic esters arylphos-
phonous acids is well known [11]. However, this
process is unlikely to contribute much into the overall
scheme of the reaction in hand. Thus, the mixture
obtained by barboting dry air free of HCl for half an
hour through a solution of phosphonite I in benzene
contained, by 31P NMR data, no more than 1% of
phosphonate IV. The formation of additional amount
of cyclic phosphonate IV in the course of distillation
of the reaction product may well be represented by
schemes (3) and (4), since the intramolecular cycliza-
tion of phosphonates and monoesters of orthophos-
phoric acid, containing 2-haloalkyl radicals in the
ester has been described [12]. In principle, compound
IV might be formed by direct cyclization of com-
pound III with elimination of a 1,2-dichloroethane
molecule. However, such process did not observed on
distillation of pure acyclic phosphonate III.
first contained 33% of linear phosphonate III, 42% of
1
the hydrophosphoryl compound [ P 27.13 ppm ( J
PH
5
54 Hz)], and 25% of dioxaphospholane IV (see
figure, spectrum f). The second contained 37% of
phosphonate III and 42% of phosphonate IV (see
figure, spectrum g). Thus, the content of cyclic
phosphonate IV much increased during distillation.
We suggest that the reaction of dioxaphospholane
I with HCl may occur by a way depicted by the fol-
lowing schemes. Therewith, reactions (1) and (2)
proceed fast at room temperature, whereas reactions
(
3) and (4) require thermal activation. Phenylphos-
phine, phosphonate III, and phenylphosphonous acid
are probably formed by transformation of intermediate
phosphinate II. We did not isolate phenylphos-
pohnous acid, but the published 31P NMR data [10]
correspond to characteristics of the hydrophosphoryl
compound detected in the crude mixture. At the same
time, the stoichiometry of the final reaction products,
presented in scheme (2), corresponds to the intensity
ratio of their signals in the final reaction mixture
before thermal treatment.
This process might be studied in more detail with
an individual compound II. It might be prepared by
partial hydrolysis of bis(2-chloroethyl) phenylphos-
phonite (V) in the presence of HCl. We tried to
O
HCl
prepare compound V by reaction of PhPCl with
2
[
Oligomers, phosphoranes]
O
Ph P
2
-chloroethane in the presence of triethylamine.
O
I
However, the fraction obtained by distillation of the
crude reaction mixture contained, by 13C and
NMR data, 50% of the isomeric 2-chloroethyl
2-chloroethyl)phenylphosphinate. This result might
31
P
(
(
1)
Ph P OCH CH Cl,
2
2
H
O
(
II
O
well be expected, since the tendency of dialkyl phenyl-
phosphonites for thermal rearrangement with forma-
tion of the second P C bond is a known fact [13]. At
the same time, Mukaiyama et al. [6] described the
polymerization of cyclic phosphonites in rigid condi-
tions (>150 C in the presence of catalysts or pro-
longed heating at 200 C without catalysts), leading to
phosphoryl compounds with two P C bonds. Detailed
inspection of the 31P and C NMR spectra of crude
reaction mixtures gives us grounds to state that the
above-described processes produce no compounds
containing a PhP(O)C fragment.
OH
H
4
II
PhPH + 2Ph P (OCH CH Cl) + Ph P
,
2
2
2
2
III
2)
O
O
OH
H
Ph P
+ III
Ph P OCH CH Cl + II, (3)
2 2
OH
O
O
O
O
13
+
HCl.
(4)
Ph P OCH CH Cl
Ph P
2
2
OH
IV
Thus, scheme (2) formally reflects disproportiona-
Thus, the reaction of phosphonite I with HCl oc-
curs in an intricate fashion and always gives a mixture
of products from the very beginning. The facility of
exchange processes accompanying this reaction makes
it unsuitable from a preparative standpoint. The fact
that the reaction studied gives the same products as
reactions of dichlorophosphines with vicinal diols and
glycidol suggests a common mechanism of these two
types of processes.
tion of hydrogen phosphonite II. However, it is
unclear why this reaction which even with free phos-
phonous (phosphinous) acids RPO H requires rigid
2
2
conditions to occur and has not yet described for their
esters [7], in our case occurs rather fast at room
temperature. We suggest that the transformations
illustrated by the schemes are induced by fast ex-
change processes catalyzed by hydrogen chloride,
rather than redox reactions.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 6 2003

COVERSIONS OF 2-PHENYL-1,3,2-DIOXAPHOSPHOLANE
931
EXPERIMENTAL
Bis(2-chloroethyl) phenylphosphonate (III). A
solution of 3.14 g of 2-chloroethanol in 20 ml of dry
benzene was added dropwise with stirring under argon
to a solution of 3.8 g dichloro(phenyl)phosphine and
3.94 g of triethylamine in 20 ml of the same solvent,
maintaining the temperature at 5 C using an ice bath.
The mixture was stirred for 1 h at 40 C and cooled to
room temperature. The precipitate was filtered off, the
filtrate was evaporated at reduced pressure, and the
residue was distilled in a vacuum to obtain 4.78 g
The NMR spectra were obtained on Bruker WM-
1
13
2
50 ( H, 250.1 MHz; C, 62.9 MHz) and Bruker
3
1
CXP-100 ( P, 36.5 MHz) instruments relative to
1
13
31
internal TMS ( H, C) and external H PO ( P) in
3
4
1
13
31
CDCl ( H, C), C H ( P).
3
6
6
2
-Phenyl-1,3,2-dioxaphospholane (I). A solution
of 8.28 g of dichloro(phenyl)phosphine in 50 ml of
dry benzene was added dropwise with stirring under
nitrogen to a solution of 2.87 g of ethylene glycol and
2
0
(
87%) of phosphonate III, bp 134 C (0.8 mm), n
D
1
1
.5251. H NMR spectrum, , ppm (J, Hz): 3.69 t.d
1
4.51 g of triethylamine in 50 ml of dry benzene,
4
3
(
2H, CH Cl, J 1.6, J 5.8), 4.17 4.38 m (2H,
2
PH
HH
maintaining the temperature at 5 C using an ice bath.
The reaction mixture was refluxed for 1 h and cooled
to room temperature. The precipitate was filtered off,
the filtrate was concentrated at reduced pressure and
distilled in a vacuum to obtain 5.2 g (67%) of com-
OCH ), 7.41 7.60 m (3H, Ph), 7.77 7.89 m (2H, Ph).
2
1
3
C NMR spectrum, , ppm (J, Hz): 42.34 d (CH Cl,
C
2
3J 5.5), 64.96 d (OCH , J 4.7), 126.44 d, 127.94
2
PC
2
PC
1
3
d, 130.99 d and 132.27 d (Ph, J 189.8, J 14.8,
JPC 10.0 and JPC 2.9). P NMR spectrum:
20.09 ppm.
PC
PC
2
4
31
P
pound I, bp 82 C (0.8 mm) {bp 79 80 C (0.8 mm)
6]}. 3 P NMR spectrum:
1
[
162.40 ppm.
P
Reaction of PhPCl2 with 2-chloroethanol. A
Reaction of dioxaphospholane I with HCl was
solution of 2.58 g of PhPCl in 20 ml benzene was
performed by the procedure described in [6]. Hydro-
gen chloride dried with sulfuric acid was barboted
over the course of 2 h through a solution of 4.4 g of
compound I in 10 ml of dry benzene. Heat release
was observed first 10 min. After barboting of HCl had
2
added dropwise under argon at 5 C to a stirred solu-
tion of 3.23 g of 2-chloroethanol and 6.14 ml of tri-
ethylamine in 25 ml of the same solvent. The mixture
was stirred for 1 h at 40 C and then cooled. The
precipitate was filtered off, the solvent was removed
at reduced pressure, and the residue was distilled in a
vacuum to obtain a single fraction [4.8 g, bp 118
3
1
been complete, the P NMR spectrum of the reaction
mixture was measured, and then the solvent and
volatile phenylphosphine were removed in a vacuum.
The residue was distilled in a vacuum to obtain 0.7 g
of a fraction [bp 147 C (0.8 mm)] containing 33% of
1
20 C (0.8 mm)] containing bis(2-chloroethyl)
phenylphosphonite (V) {bp 138 140 C (3 mm)
1
3
[
(
1
1
1
14]} [ C NMR spectrum, , ppm (J, Hz): 42.68 d
phosphonate III, 42% of hydrophosphoryl compound
C
3
2
1
CH Cl, J 7.00), 66.22 d (OCH , J 8.7), 128.0 d,
( P 27.13 ppm, J 554 Hz), and 25% of 2-phenyl-
2 PC 2 PC
PH
3
2
1
3
29.35 d, 129.93 s and 139.35 d (Ph, J 5.2, J
PC
9.2 and JPC 20.1);
1
,3,2-dioxaphospholan-2-one (IV) [ C NMR spec-
trum, , ppm (J, Hz)]: 65.95 s (OCH ), 126.42 d,
27.91 d, 130.80 d, 132.30 d (Ph, J 185.6, J
5.1, J 10.3, J 2.6); P NMR spectrum:
PC
1
31
P NMR spectrum:
P
C
2
1
3
61.38 ppm] and its isomer (2-chloroethyl) (2-chloro-
1
1
3
PC
PC
P
1
3
2
4
31
ethyl)phenylphosphinate [ C NMR spectrum, C,
PC
PC
1
ppm (J, Hz): 33.78 d (PCH , J 94.2), 36.76 s
7.14 ppm] and 2 g of a fraction [bp 190 215 C
2
PC
3
3
1
(
CH Cl), 43.70 d (CH Cl, J 5.2), 63.80 d (OCH2,
(
0.8 mm)] containing, according to the P NMR spec-
2 2 PC
2
JPC 6.1), 128.56 d, 129.15 d, 131.16 d and 132.65 d
trum, 37% of phosphonate III and 41% of phos-
phonate IV; 22% falled at three signals ( P 11, 14,
and 17 ppm).
3
1
2
4
(
Ph, J 13.1, J 126.4, J 10.6 and J 2.4);
PC PC PC PC
3
1
P NMR spectrum:
40.44 ppm].
P
Monitoring of the reaction of phosphonite I with
HCl by 31P NMR spectroscopy. Concentrated H SO4
REFERENCES
2
was added in portions of 5 10 drops to 0.92 g of
1
. Cherkasov, R.A. and Pudovik, M.A., Usp. Khim.,
994, vol. 63, no. 12, p. 1087.
NH Cl. The HCl formed was barboted with a stream
4
1
of dry nitrogen through a drying flask with H SO4
2
2
. Bredikhin, A.A., Lazarev, S.N., Bredikhina, Z.A., and
Al’fonsov, V.A., Phosphorus, Sulfur Silicon, 1997,
vol. 131, p. 173.
into a solution of 2.9 g of phosphonite I in 8 ml of
benzene until HCl no longer evolved ( 20 min). After
3
1
that, a sample was taken to measure the P NMR
spectrum. When ammonium chloride had completely
reacted, the mixture was left to stand in a closed
system for 1.5 day, after which excess HCl was
3. Bredikhin, A.A., Lazarev, S.N., and Bredikhina, Z.A.,
Zh. Obshch. Khim., 1997, vol. 67, no. 11, p. 1806.
4. Bredikhin, A.A., Lazarev, S.N., Efremov, Yu.Ya.,
Sharafutdinova, D.R., and Bredikhina, Z.A., Zh.
Obshch. Khim., 2000, vol. 70, no. 5, p. 759.
3
1
barboted into it, and the P NMR spectrum was
measured.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 6 2003

9
32
LAZAREV et al.
5
6
7
. Richter, W.J., Phosphorus, Sulfur Silicon, 1981, 11. Arbuzov, B.A. and Rizpolozhenskii, N.I., Izv. Akad.
vol. 10, no. 3, p. 395.
Nauk SSSR, Ser. Khim., 1952, no. 5, p. 854.
. Mukaiyama, T., Fujisawa, T., Tamura, Y., and Yoko-
ta, Y., J. Org. Chem., 1964, vol. 29, no. 9, p. 2572.
12. Purdela, D. and Vilceanu, R., Chimia Compulsor
Organici ai Fosforului si ai Acizilor lui, Bucharest:
Acad. Republicii Socialiste Romania, 1965. Trans-
lated under the title Khimiya organicheskikh soedi-
nenii fosfora, Moscow: Khimiya, 1972, p. 676.
. Nifant’ev, E.E., Khimiya gidrofosforil’nykh soedinenii
(
Chemistry of Hydrophosphoryl Compounds),
Moscow: Nauka, 1983.
8
. Dutasta, J.P., Guimaraes, A.C., Martin, J., and Ro-
bert, J.B., Tetrahedron Lett., 1975, vol. 18, no. 18,
p. 1519; Dutasta, J.P., Grand, A., Guimaraes, A.C.,
and Robert, J.B., Tetrahedron, 1979, vol. 35, no. 2,
p. 197.
13. Pudovik, A.N. and Krupnov, V.K., Zh. Obshch. Khim.,
1968, vol. 8, no. 6, p. 1287; Gefter, E.L. and Roga-
cheva, I.A., Metody polucheniya khimicheskikh re-
aktivov i preparatov (Methods of Preparation of
Chemicals), Moscow: Khimiya, 1969, no. 18, p. 111.
9
. Malavaud, C., Charbonnel, Y., and Barrans, J., Tetra-
hedron Lett., 1975, vol. 16, no. 8, p. 497.
1
4. Kormachev, V.V. and Fedoseev, M.S., Preparativ-
naya khimiya fosfora (Preparative Chemistry of Phos-
phorus), Perm: Izd. Ural. Otd. Ross. Akad. Nauk,
1992, p. 122.
1
0. Andreev, N.A. and Grishina, O.N., Zh. Obshch. Khim.,
979, vol. 49, no. 10, p. 2230.
1
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 73 No. 6 2003