3,3-Bis(diethylphosphono)-1(3H)-isobenzofuranone and its properties

Full text of DOI:10.1134/S1070363210080256

ISSN 1070-3632, Russian Journal of General Chemistry, 2010, Vol. 80, No. 8, pp. 1720–1721. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © V.N. Zemlyanoi, V.P. Kukhar’, О.I. Kolodyazhnyi, 2010, published in Zhurnal Obshchei Khimii, 2010, Vol. 80, No. 8, pp. 1399–
1400.
LETTERS
TO THE EDITOR
3,3-Bis(diethylphosphono)-1(3H)-isobenzofuranone
and Its Properties
V. N. Zemlyanoi, V. P. Kukhar’, and О. I. Kolodyazhnyi
Institute of Bioorganic and Petroleum Chemistry, National Academy of Sciences of Ukraine,
ul. Murmanskaya 1, Kiev, 02094 Ukraine
e-mail: olegkol321@rambler.ru
Received January 14, 2010
DOI: 10.1134/S1070363210080256
The reaction of о-phthalyl chloride with sodium
diethylphosphite was found to give 3,3-bis(diethyl-
phosphono)-1(3H)-isobenzofuranones I. The reaction
evidently proceeds through the formation of keto-
phosphonate А, which reacts with the second molecule
of sodium diethylphosphite in keeping with the
mechanism of 1,1-diphosphorylation and results in
isobenzofuranone I through intramolecular cyclization
of intermediate B.
spectrum contains signal of the carbon atom bonded
with two phosphorus atoms as a triplet at 83.26 ppm
(JPC 155.9 Hz) proving the presence of 1,1-bis-
phosphonate fragment.
Refluxing of 1(3H)-isobenzofuranone with potas-
sium carbonate leads to the ring opening and the
elimination of one phosphonate group to give acyclic
1-ketophosphonate II. At the same time refluxing of
bisphosphonate I in the concentrated hydrochloric acid
do not lead to ring opening, but affords bisphosphinic
acid III in high yield, which was earlier obtained by
another method [1].
The structure of bisphosphonate I was confirmed
1
by Н, 13С, 31Р NMR, mass- and IR spectral data, and
also by chemical transformations. Thus, the 13С NMR
O
O
O
(EtO)2PONa
Cl
Cl
P(OEt)2
Cl
O
O
A
O
O
O
O
(OEt)2P
P(OEt)2
(OEt)2P
P(OEt)2
(EtO)2PONa
ONa
Cl
O
_NaCl
O
O
B
I
P(O)(OEt)2
(HO)2P(O)
P(O)(OH)2
K2CO3/H2O
HCl/H2O
O
I
O
CO2H
O
II
III
1720

3,3-BIS(DIETHYLPHOSPHONO)-1(3H)-ISOBENZOFURANONE
1721
3,3-Bis(diethylphosphono)-1(3H)-isobenzofuranone
(I). To diethylphosphite sodium salt obtained from
1.0 g of sodium and 4.7 ml of diethylphosphite, in
40 ml of anhydrous diethyl ether was added 2.9 ml of
о-phthaloyl dichloride over 10–15 min at stirring and
cooling to -40°С. Then the reaction mixture was stirred
for 1–2 h, raising the bath temperature gradually to
ambient, after which the mixture was refluxed for 1–
2 h. The precipitate was filtered off and washed with
ethyl acetate. The filtrate was concentrated under
reduced pressure, and the residue was recrystallized
from a mixture ethyl acetate–hexane in the ratio 1:2.
Yield 3.2 g (40%). Bisphosphonate I can be also
purified by sublimation in a vacuum at 0.1 mm Hg at
100–120°С, mp 90–91°С. IR spectrum, ν, cm–1 (ССl4):
2988.57 m (СH), 1781.74 s (C=O), 1262.43 s (P=O),
cooled with ice water and acidified with diluted
sulfuric acid to рН 2-3. o-Phthalic acid was filtered off
and the filtrate was extracted with ethyl acetate. The
solution was concentrated under reduced pressure. The
residue was recrystallized from hexane, mp 165oС.
1
Yield 0.12 g (80%). Н NMR spectrum [(CD3)2CO],
δ, ppm (J, Hz): 1.21 t (6Н, Ме); 3.97 d.q (4Н, ОСН2,
JPH 7, JHH 7); 6.64 s (1Н, СО2Н); 7.63 t (1Н, Н5, JHH
6); 7.69 d.d (1Н, H7, JНН 6); 7.76 d (2Н, H4, H7, JHH 6).
31Р NMR spectrum, δР, ppm (СDСl3): +1.19.
3-Oxo-1,1(3H)-isobenzofurandiphosphonic acid
(III). A solution of 0.2 g of bisphosphonate II in 1 ml
of concentrated hydrochloric acid was refluxed for 3–
4 h to complete release of ethyl chloride, adding 1 ml
of hydrochloric acid every hour. Then the solution was
concentrated in a vacuum. The residue was re-
crystallized from ethyl acetate. Yield 0.12 g (82.9%),
1
1022.40 s (P–O–C). Н NMR spectrum (CDCl3), δ,
ppm (J, Hz): 1.08 t (6Н, СН3, JРH 7); 1.27 t (6Н, СН3,
JPH 7); 3.91 m (2Н, ОСН2-trans); 4.02 m (2Н, ОСН2-
trans); 4.26 m (4Н, ОСН2-cis); 7.55 d.d (1Н, Н5, JНH
6, JНH 8); 7.69 d.d (1Н, Н6, JНH 6, JНH 8); 7.88 d (2Н,
Н4+Н7, JНH 6). 13C NMR spectrum (CDCl3), δ, ppm:
16.09 (СН3); 16.32 (СН3); 64.82 (СН2); 65.14 (ОСН2);
83.26 t (С1, JPC 155.9); 124.85 (С9, JPC 3); 124.95 (С7);
125.84 (С4); 130.04 (С5); 134.33 (С6); 143.73 (С8);
169.14 (С=О). 31Р NMR spectrum, δР, ppm (CDCl3):
+10.28. Mass-spectrum, m/e: 406. Found, %: C 47.30,
H 5.85, P 14.92. С16Н24O8P2. Calculated, %: C 47.30;
H 5.95; P 15.25.
1
mp > 260°C. The H and 31Р NMR spectra data and
1
melting point correspond to published data [2]. Н
NMR spectrum (DMSO-d6), δ, ppm (J, Hz): 7.57 d.d
(1Н, Н5, JHH 7); 7.75 d.d (1Н, Н7, J 6); 7.80 d (2Н, H4,
H7, JHH 7). 31Р NMR spectrum, δР, ppm (DMSO-d6):
+8.02.
The NMR spectra were recorded on a Varian-300
instrument relative to internal TMS (1Н, 13С) and 85%
Н3РО4 in D2O (31Р).
REFERENCES
2-(Diethylphosphorylcarbonyl)benzoic acid (II).
A mixture of 0.20 g of bisphosphonate I and 0.2 g of
potassium carbonate in 2 ml of water was refluxed for
0.5 h to complete release of СО2. The solution was
1. Guenin, E., Degache, E., Liquier, J., and Lecouvey, M.,
Eur. J. Org. Chem., 2004, vol. 14, p. 2983.
2. Kehler, J. and Breuer, E., Synthesis, 1998, vol. 10,
p. 1419.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 80 No. 8 2010