Synthesis and herbicidal activity of O,O-dialkyl phenoxyacetoxyalkylphosphonates containing fluorine

Article abstract of DOI:10.1016/j.jfluchem.2005.11.013

A series of substituted phenoxyacetoxyalkylphosphonates bearing fluorine were designed and synthesized. All the new compounds were identified by elemental analysis, IR, ¹H NMR and MS and were tested for herbicidal activity in greenhouse at a rate of 1.5 kg/ha. The results of preliminary bioassay showed that fluorine moiety introduced to the core structure could help to improve the herbicidal activity, and compounds with a 3-trifluoromethyl in benzene ring exhibited higher inhibitory activity.

Full text of DOI:10.1016/j.jfluchem.2005.11.013

Journal of Fluorine Chemistry 127 (2006) 291–295
www.elsevier.com/locate/fluor
Short communication
Synthesis and herbicidal activity of O,O-dialkyl
phenoxyacetoxyalkylphosphonates containing fluorine
*
Ting Chen, Ping Shen, Yanjun Li, Hongwu He
Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry,
Central China Normal University, Wuhan 430079, PR China
Received 13 August 2005; received in revised form 4 November 2005; accepted 11 November 2005
Abstract
A series of substituted phenoxyacetoxyalkylphosphonates bearing fluorine were designed and synthesized. All the new compounds were
identified by elemental analysis, IR, 1H NMR and MS and were tested for herbicidal activity in greenhouse at a rate of 1.5 kg/ha. The results of
preliminary bioassay showed that fluorine moiety introduced to the core structure could help to improve the herbicidal activity, and compounds
with a 3-trifluoromethyl in benzene ring exhibited higher inhibitory activity.
# 2005 Elsevier B.V. All rights reserved.
Keywords: Fluorophenoxyacetic acid; 1-Hydroxyl alkylphosphonates; Synthesis; Herbicidal activity
1. Introduction
stituted phenoxyacetoxyalkylphosphonates, nor the systema-
tic structure–activity study of this kind of compound. This
ideal encouraged us to introduce fluorine moiety to the core
structure as a continuous research of our previous work.
Here, we report our recent study about the synthesis
and herbicidal activity of a novel series of O,O-dialkyl
1-(fluorosubstituted) phenoxyacetoxyalkylphosphonates (5a–
5l).
Fluorine is a very unique element with the highest
electronegativity, smallest size next to hydrogen, high thermal
stability and lipophilicity, which endows various prominent
functionality in the organofluorine compounds. By introducing
fluorine atom into organic molecules, we can get compounds
with improved physical, chemical and biological properties [1–
3]. So, the application of fluorides in pharmaceuticals and
pesticides attracted more and more attention. Some examples
demonstrated that fluorine-introducing could influence the
herbicidal activity [4], fungicidal activity [5] and insecticidal
activity [6] of certain compounds.
2. Results and discussions
2.1. Synthesis
How to find effective herbicides with novel structures and
mode of action has become a new focus of pesticide
discovery. For a long time, our group was actively engaged in
the research of bioactive organophosphonates. Recent study
revealed that 1-oxophosphonic acid derivatives, which
possessed good herbicidal activities, could act as a leading
structure for herbicide designing [7]. However, our previous
work was devoted to neither the synthesis of fluorosub-
Compound 1 could be easily synthesized starting from
fluorophenol and bromoacetic ester [8]. Dimethyl phosphite
and diethyl phosphite 3 were obtained by the reported method
[9]. The preparation of title compounds involved the
condensation of fluorophenoxyacetyl chloride moiety 2 and
O,O-dialkyl 1-hydroxylalkylphosphonates moiety 4. As the
target phosphonate derivatives containing groups sensitive to
acid, base or water, such as carboxylic ester, so the reaction
required a temperature near room temperature and the reagent
in anhydrous solvents. The synthetic pathway was outlined in
Scheme 1 and the structures of title compounds 5a–5l were
given in Table 1.
* Corresponding author. Tel.: +86 27 67867960; fax: +86 27 67867960.
E-mail addresses: he1208@public.wh.hb.cn,
he1208@mail.ccnu.edu.cn (H.W. He).
0022-1139/$ – see front matter # 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jfluchem.2005.11.013

292
T. Chen et al. / Journal of Fluorine Chemistry 127 (2006) 291–295
Scheme 1.
2.2. Biological activities
a spelling volume of 1000 L/ha. All the treatments were
replicated three times in a completely randomized design. The
test plants were harvested 20 days after sowing, and determined
for fresh weight. The post-emergence herbicidal activity
against each weed was evaluated. The percentage growth
inhibition of roots and aerial parts were calculated in relation to
the mass of the roots and aerial parts of the control respectively.
The results of 5a–5l were listed in Table 1.
As seen from Table 1, compounds 5a–5d showed much
better activity than that of compounds 5e, 5f, 5g, 5h, 5k, 5l.
Compounds 5a–5d exhibited notable pre-emergence inhibitory
effects against a variety of plants species, specially 5a, 5b, 5d
showed good pre-emergence and post-emergence inhibitory
effects against dicotyledon. Such as Amaranthus retroflerus L.
and Medicago Satival.
The herbicidal activities of compounds 5a–5l were
evaluated at a rate of 1.5 a.i. kg/ha in a set of experiment in
greenhouse. They were tested for pre-emergence and post-
emergence inhibitory effect against Echinochloa Crusgalli
Beava (barngard grass), Digitaria Sanguinalis scop (ascendant
crabgrass), Brassica napus L. (rape), Amaranthus retroflerus L.
(amaranth) and Medicago Satival (clover).
Plastic pots were packed with sandy clay loam soil and water
was added up to 3 cm in depth. About 15–20 seeds of plants
were sown in the soil at a depth of 5 mm and grown at 20–25 8C
for a few days. The diluted solution of each compound
containing acetone and Tween 80 were applied into the pots at
1.5 a.i. kg/ha. Twenty days later, the pre-emergence herbicidal
activity was visually evaluated. At the post-emergence, the
solution was applied to the foliage of plants grown at two to
three leaves stage with a sprayer at the rate of 1.5 a.i. kg/ha with
Compounds 5m–5n [10] and 5o–5t [11–13] also listed in
Table 1 were employed to discuss about the bioactivity. They
were obtained from our previous work.
Table 1
Herbicidal activity of compounds 5a–5t (1.5 a.i. kg/ha, relative inhibition of growth percent)
Compound
X
Y
R1
R2
Ech.
Pre
Dig.
Pre
Bra.
Pre
Ama.
Pre
Med.
Pre
Post
Post
Post
Post
Post
100
5a
5b
5c
5d
5e
5f
5g
5h
5i
5j
5k
5l
5m [10]
5n [10]
5o [11]
5p [12]
5q [12]
5r [12]
5s [13]
5t [13]
H
3-CF3
3-CF3
3-CF3
3-CF3
2-F
CH3
C2H5
CH3
C2H5
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
C2H5
C2H5
3-ClPh
3-ClPh
4-FPh
4-FPh
Ph
62.8
73.5
68.5
35.5
0
37.5
0
87.2
0
22.1
59.6
37.6
35.2
49.6
0
100
95.5
67.7
77.3
0
92.3
84.5
57.6
88.5
0
93.2
96.6
89.7
100
0
H
72.3
86.6
8.0
51.6
82.7
50.4
0
88.3
H
16.0
8.3
16.0
32.0
18.2
33.9
10.4
0
100
100
0
H
100
H
27.3
80.3
0
0
0
H
2-F
3-NO2Ph
Ph
0
0
17.3
3.0
0
0
0
0
0
H
3-F
0
0
0
0
48.6
6.8
77.5
71.1
14.9
39.0
43.8
37.3
0
0
0
H
3-F
3-NO2Ph
CH3
0
19.4
20.2
21.6
3.8
5.4
73.6
64.3
0
0
0
0
0
2-F
2-F
3-F
3-F
2-Cl
2-Cl
H
4-F
36.0
11.8
0
48.5
46.2
27.2
12.6
35.0
22.7
0
39.3
17.6
0
61.0
41.2
0
38.9
25.0
0
52.1
64.6
10.4
0
49.4
4-F
CCl3
49.4
5-F
CH3
0
0
0
0
\
5-F
CCl3
8.1
19.1
5.1
\
22.5
13.6
6.1
0
6.2
15.2
23.3
0
0
3-Cl
CH3
0
0
16.7
0
8.3
20.8
\
3-Cl
CCl3
0
24.1
62.17
0.9
4-CH3
2-NO2
4-NO2
4-NO2
3-CF3
3-CF3
CH3
47.4
0
0
30.9
0
\
H
3-NO2Ph
Ph
2.3
0.8
À1.1
90.2
88.3
6.7
0
0.3
\
\
\
\
H
0
À5.2
0.3
À2.78
À16.7
43.3
33.9
5.49
\
\
\
\
H
3-NO2Ph
Ph
À2.5
51.4
0
5.26
100
97.9
À1.1
83.7
61.7
\
\
\
\
H
16.0
32.0
91.0
100
84.6
84.6
100
100
100
83.3
H
3-NO2Ph
Post, post-emergence treatment; pre, pre-emergence treatment; Ech., Echinochloa crusgalli Beava; Dig., Digitaria sanguinalis Scop; Bra., Brassica napus L.; Ama.,
Amaranthus retroflerus L.; Med., Medicago sativa; rate of compound 5o was 2.25 kg/ha; \, the data for the activity was not tested.

T. Chen et al. / Journal of Fluorine Chemistry 127 (2006) 291–295
293
The results indicated that fluorine moiety introduced to O,O-
3.2. Synthesis of O,O-dialkyl 1-hydroxylalkphosphonate
(4)
dialkyl 1-(substituted) phenoxyacetoxyalkylphosphonate’s
structure was useful for the improvement of herbicidal activity.
Especially, the introducing of trifluoromethyl group made for
prominent enhancement on inhibitory activity.
O,O-Dimethyl 1-hydroxyalkylphosphonate or O,O-diethyl
1-hydroxyalkylphosphonate 4 could be prepared by the
reaction of dimethyl phosphite or diethyl phosphite 3 and
several kinds of aldehydes using potassium fluoride and
alumina (mass ratio was 1:1) as catalyst in yield of 65–94%
according to literatures [14,15].
From the table, we noticed that the structure and position of
substituents X, Y in benzene ring had great influence on the
herbicidal activity. For monosubstituted benzene ring, trifluor-
omethyl substituted compounds have the best activity. For
disubstituted benzene ring, the combination of 2-F, 4-F was
better than that of 3-F, 5-F and 2-Cl, 3-Cl. Comparing
compounds 5i–5l with 5e–5h, obvious increasement of
inhibitory activity was observed by introducing two fluorine
atoms. Whereas the change of other substituents, such as R1 or
R2, has only a little influence on their activity. Further exploring
of structure–activity relationship need more experimental
results to support. In our group, the QSAR studies of
substituted phenoxyacetoxyalkylphosphonates, including the
title compounds, are in process.
3.3. General synthesis of
fluorophenoxyacetoxyalkylphosphonates (5a–5l)
A solution of fluorophenoxyacetyl chloride 2 (0.011 mol) in
trichloromethane (15 mL) was added to stirred mixture of 1-
hydroxy alkylphosphonate 4 (0.01 mol) and triethyl amine
(0.011 mol) in trichloromethane (15 mL) at 2–4 8C. The
resultant mixture was stirred at ambient temperature for 2–
3 h, then washed with 0.1 mol/L HCl, saturated NaHCO3 and
brine separately, dried and evaporated. The residue was
chromatographed on silica with 20% acetone in petroleum
ether as eluent to give the compounds 5a–5l as a yellow liquid
or white solid.
As a conclusion, the herbicidal activity of the title
compounds could be improved to some extent by introducing
fluorine moiety to benzene ring. However, it needed reasonable
combination of the structure and position of substituents at the
benzene ring. These results provided some interesting hints for
further study of structure modification and structure–activity
relationship of this kind of compounds.
3.3.1. O,O-Dimethyl 1-(3-
trifluoromethylphenoxyacetoxy)3-chlorobenzylphosphonate
(5a)
3. Experimental
Oil: yield 70.1%; nD20 1.5138; 1H NMR (400 Hz, CDCl3) d:
3.65–3.79 (m, 6H, 2OCH3), 4.75 (s, 2H, OCH2CO), 6.18–6.20
(d, 1H, OCHP, JHP = 13.3 Hz), 7.04–7.47 (m, 8H, 2C6H4); IR
(KBr) (cmÀ1): 3076 (Ar–H), 1753 (C O), 1265 (P O), 742 (P–
C); EIMS (probe) 70 eV, m/z (rel. int.): 452 [M]+ (17.49), 175
(98.3), 109 (70.87), 93 (100); anal. calc. for C18H17O6PF3Cl: C,
47.73, H, 3.76. Found: C, 47.85, H, 3.70%.
Mass spectra were measured on a Finnigan TraceMS 2000
spectrometer. Infrared spectra were recorded in potassium
1
bromide disks on a Nicolet Avatar360 FTIR spectrometer. H
NMR was recorded in deuterocholroform solution at 400 MHz,
using tetramethysilane as internal standard on Varian Mercury-
Plus400 spectrometer. Elemental analysis was performed by
Elementar Vario EL III elementary analyzer. Melting points
(mp) were measured on an electrothermal melting point
apparatus and temperature uncorrected. All the solvents were
dried before use. Phosphorous trichloride, triethyl amine and
thionyl chloride were distilled before the reaction. Samples
were purified by flash chromatography with silica gel.
3.3.2. O,O-Diethyl 1-(3-trifluoromethylphenoxyacetoxy)3-
chlorobenzylphosphonate (5b)
1
Crystal: yield 63.7%; mp 36.4–36.8 8C; H NMR (400 Hz,
CDCl3) d: 1.25–1.30 (m, 6H, 2OCH2CH3), 3.82–4.20 (m, 4H,
2OCH2CH3), 4.77 (s, 2H, OCH2CO), 6.18–6.20 (d, 1H, OCHP,
HP = 13.3 Hz), 7.03–7.47 (m, 8H, 2C6H4); IR (KBr) (cmÀ1):
J
3070 (Ar–H), 1750 (C O), 1263 (P O), 742 (P–C); EIMS
(probe) 70 eV, m/z (rel. int.): 480 [M]+ (27.91), 175 (94.21),
121(100), 93 (84.43); anal. calc. for C20H21O6PF3Cl: C, 49.95,
H, 4.37. Found: C, 50.10, H, 4.42%.
3.1. Synthesis of fluorophenoxyacetic acid (1) and
fluorophenoxyacetyl chloride (2)
To a three-neck boiling flask, fluorophenol (0.04 mol),
bromoacetic ester (0.042 mol), potassium carbonate (5.8 g)
were added by order, then Me2SO (100 mL) was added as
solvent. The mixture was stirred and kept at 70–80 8C for 5 h,
then was treated with ice-water immediately. After the yellow
solid was filtered off, and dissolved in acetone (20 mL), 2 mol/
L NaOH was added, then stirred for another 2 h at room
temperature. Then added 2 mol/L HCl and the fluorophenox-
yacetic acid 1 formed. The solid could be recrystalized as white
crystal in yield of 70%. The corresponding fluorophenoxya-
cetyl chloride 2 could be easily obtained as a yellow liquid in
90% yield by treated compound 1 with thionyl chloride.
3.3.3. O,O-Dimethyl 1-(3-
trifluoromethylphenoxyacetoxy)4-fluorobenzylphosphonate
(5c)
Crystal: yield 79.2%; mp 69.3–69.5 8C; 1H NMR (400 Hz,
CDCl3) d: 3.62–3.79 (m, 6H, 2OCH3), 4.77 (s, 2H, OCH2CO),
6.61–6.67 (d, 1H, OCHP, JHP = 13.3 Hz), 7.04–7.34 (m, 8H,
2C6H4); IR (KBr) (cmÀ1): 3070 (Ar–H), 1748 (C O), 1263
(P O), 742 (P–C); EIMS (probe) 70 eV, m/z (rel. int.): 436
[M]+ (1.06), 175 (97.13), 145 (100), 93 (17.99); anal. calc.
for C18H17O6PF4: C, 49.54, H, 3.90. Found: C, 49.00, H,
3.57%.

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T. Chen et al. / Journal of Fluorine Chemistry 127 (2006) 291–295
3.3.4. O,O-Diethyl 1-(3-trifluoromethylphenoxyacetoxy)4-
fluorobenzylphosphonate (5d)
4.72 (s, 2H, OCH2CO), 5.31–5.47 (m, 1H, OCHP,
JHP = 13.3 Hz), 6.79–7.96 (m, 3H, C6H3); IR (KBr) (cmÀ1):
3069 (Ar–H), 1744(C O), 1262 (P O), 740 (P–C); EIMS
(probe) 70 eV, m/z (rel. int.): 324 [M]+ (80.71), 138 (100), 109
(92.21), 93 (83.78); anal. calc. for C12H15O6PF2: C, 44.46, H,
4.66. Found: C, 44.73, H, 4.45%.
Oil: yield 70.1%; nD20 1.4945; 1H NMR (400 Hz, CDCl3) d:
1.20–1.30 (m, 6H, 2OCH2CH3), 3.90–4.20 (m, 4H,
2OCH2CH3), 4.79 (s, 2H, OCH2CO), 6.30–6.38 (d, 1H, OCHP,
J
HP = 13.3 Hz), 7.03–7.47 (m, 8H, 2C6H4); IR (KBr) (cmÀ1):
3069 (Ar–H), 1747 (C O), 1263 (P O), 744 (P–C); EIMS
(probe) 70 eV, m/z (rel. int.): 465 [M]+ (6.13), 175 (79.02),
121(100); anal. calc. for C20H21O6PF4: C, 51.72, H, 4.53.
Found: C, 51.72, H, 4.69%.
3.3.10. O,O-Dimethyl 1-(2,4-
difluorophenoxyacetoxy)trichloromethylmethylphosphonate
(5j)
Crystal: yield 65.2%; mp 67.9–68.5 8C; 1H NMR (400 Hz,
CDCl3) d: 3.81–3.93 (m, 6H, 2OCH3), 4.66 (s, 2H, OCH2CO),
5.96–5.97 (d, 1H, OCHP, JHP = 13.3 Hz), 6.79–7.28 (m, 3H,
C6H3); IR (KBr) (cmÀ1): 3078 (Ar–H), 1744 (C O), 1263
(P O), 744 (P–C); EIMS (probe) 70 eV, m/z (rel. int.): 426
[M]+ (44.23), 205 (79.71), 109 (99.59), 93 (100); anal. calc. for
C12H12Cl3O6PF2: C, 33.71, H, 2.83. Found: C, 33.54, H,
2.62%.
3.3.5. O,O-Dimethyl 1-(2-
fluorophenoxyacetoxy)benzylphosphonate (5e)
1
Crystal: yield 64.0%; mp 67.2–67.8 8C; H NMR (400 Hz,
CDCl3) d: 3.62–3.72 (m, 6H, 2OCH3), 4.83 (s, 2H, OCH2CO),
6.25–6.28 (d, 1H, OCHP, JHP = 13.2 Hz), 7.04–7.46 (m, 8H,
C6H4, C6H5); IR (KBr) (cmÀ1): 3056 (Ar–H), 1747 (C O),
1269 (P O), 740 (P–C); EIMS (probe) 70 eV, m/z (rel. int.):
368 [M]+(21.56), 109 (28.20), 93 (100); anal. calc. for
C17H18O6PF: C, 55.44, H, 4.93. Found: C, 55.56, H, 4.76%.
3.3.11. O,O-Dimethyl 1-(3,5-
difluorophenoxyacetoxy)ethylphosphonate (5k)
Oil: yield 57.2%; nD20 1.4721; 1H NMR (400 Hz, CDCl3) d:
1.50–1.56 (d, 3H, CH3), 3.77–3.82 (m, 6H, 2OCH3), 4.68 (s,
2H, OCH2CO), 5.40–5.44 (m, 1H, OCHP, JHP = 13.2 Hz),
6.42–7.48 (m, 3H, C6H3); IR (KBr) (cmÀ1): 3069 (Ar–H), 1740
(C O), 1260 (P O), 744 (P–C); EIMS (probe) 70 eV, m/z (rel.
int.): 324 [M]+ (82.39), 138 (100), 109 (93.98), 93 (84.57); anal.
calc. for C12H15O6PF2: C, 44.46, H, 4.66. Found: C, 44.65, H,
4.46%.
3.3.6. O,O-Dimethyl 1-(2-fluorophenoxyacetoxy)3-
nitrobenzylphosphonate (5f)
1
Crystal: yield 72.9%; mp 82.7–83.6 8C; H NMR (400 Hz,
CDCl3) d: 3.81–3.72 (m, 6H, 2OCH3), 4.88 (s, 2H, OCH2CO),
6.31–6.34 (d, 1H, OCHP, JHP = 13.2 Hz), 6.93–8.29 (m, 8H,
2C6H4); IR (KBr) (cmÀ1): 3078 (Ar–H), 1740 (C O), 1260
(P O), 741 (P–C) EIMS (probe) 70 eV, m/z (rel. int.): 413 [M]+
(13.09), 125 (99.27), 109 (77.36), 93 (100); anal. calc. for
C17H17O8PFN: C, 49.40, H, 4.15, N, 3.39. Found: C, 49.77, H,
3.98, N, 3.34%.
3.3.12. O,O-Dimethyl 1-(3,5-
difluorophenoxyacetoxy)trichloromethylmethylphosphonate
(5l)
3.3.7. O,O-Dimethyl 1-(3-
fluorophenoxyacetoxy)benzylphosphonate (5g)
1
Oil: yield 59.7%; n2D0 1.4892; H NMR (400 Hz, CDCl3) d:
1
Crystal: yield 65.9%; mp 48.7–49.5 8C; H NMR (400 Hz,
3.78–3.95 (m, 6H, 2OCH3), 4.86 (s, 2H, OCH2CO), 5.96–5.99
(d, 1H, OCHP, JHP = 13.3 Hz), 6.45–7.28 (m, 3H, C6H3); IR
(KBr) (cmÀ1): 3070 (Ar–H), 1747 (C O), 1265 (P O), 740 (P–
C); EIMS (probe) 70 eV, m/z (rel. int.): 426 [M]+ (28.72), 143
(94.93), 109 (1 0 0), 93 (94.17); anal. calc. for C12H12Cl3O6PF2:
C, 33.71, H, 2.83. Found: C, 33.68, H, 2.84%.
CDCl3) d: 3.63–3.72 (m, 6H, 2OCH3), 4.70 (s, 2H, OCH2CO),
6.31–6.36 (d, 1H, OCHP, JHP = 13.3 Hz), 6.61–7.47 (m, 8H,
C6H4, C6H5); IR (KBr) (cmÀ1): 3069 (Ar–H), 1744 (C O),
1269 (P O), 741 (P–C); EIMS (probe) 70 eV, m/z (rel. int.):
368 [M]+ (49.97), 125 (66.36), 109 (75.18), 95 (100); anal. calc.
for C17H18O6PF: C, 55.40, H, 4.93. Found: C, 55.94, H, 4.65%.
Acknowledgements
3.3.8. O,O-Dimethyl 1-(3-fluorophenoxyacetoxy)3-
nitrobenzylphosphonate (5h)
We gratefully acknowledge financial support of this work by
National Basic Research Program of China (2003CB114400)
and National Natural Science Foundation of China (Project
No.: 20372023).
1
Crystal: yield 61.5%; mp 83.8–84.2 8C; H NMR (400 Hz,
CDCl3) d: 3.73–3.82 (m, 6H, 2OCH3), 4.81 (s, 2H, OCH2CO),
6.32–6.35 (d, 1H, OCHP, JHP = 13.2 Hz), 6.93–8.30 (m, 8H,
2C6H4); IR (KBr) (cmÀ1): 3056 (Ar–H), 1748 (C O), 1256
(P O), 743 (P–C); EIMS (probe) 70 eV, m/z (rel. int.): 413 [M]+
(0.15), 125 (100), 109 (84.99), 93 (90.26); anal. calc. for
C17H17O8PFN: C, 49.40, H, 4.15, N, 3.39. Found: C, 49.98, H,
4.05, N, 3.22%.
References
[1] J.T. Welch, Tetrahedron 43 (1987) 3123–3125.
[2] M. Hudlicky, Chemistry of Organic Fluorine Compounds II, American
Chemical Society, Washington, DC, 1995, pp. 1119–1125.
[3] V.P. Kukhar, J. Fluorine Chem. 69 (1994) 199–205.
[4] Y.X. Liu, Q.Q. Zhao, Q.M. Wang, H. Li, R.Q. Huang, Y.H. Li, J. Fluorine
Chem. 126 (2005) 345–348.
3.3.9. O,O-Dimethyl 1-(2,4-
difluorophenoxyacetoxy)ethylphosphonate (5i)
1
Crystal: yield 68.3%; mp 38.4–40.1 8C; H NMR (400 Hz,
CDCl3) d: 1.48–1.54 (d, 3H, CH3), 3.77–3.82 (m, 6H, 2OCH3),
[5] X.Y. Xua, X.H. Qian, Z. Lia, G.H. Song, W.D. Chen, J. Fluorine Chem.
126 (2005) 297–300.

T. Chen et al. / Journal of Fluorine Chemistry 127 (2006) 291–295
295
[6] X.M. Zheng, Z. Li, Y.L. Wang, W.D. Chen, Q.C. Huang, C.X. Liu, G.H.
Song, J. Fluorine Chem. 123 (2003) 163–169.
CDCl3) d: 3.86–3.93 (m, 6H, 2OCH3), 4.95 (s, 2H, OCH2CO), 5.96–
5.97 (d, 1H, OCHP, JHP = 13.3 Hz), 6.79–7.16 (m, 3H, C6H3); IR (KBr)
(cmÀ1): 3078 (Ar–H), 1744 (C O), 1263 (P O), 744 (P–C); EIMS
(probe) 70 eV, m/z (rel. int.): 458 [M]+ (21.20), 109 (100), 93 (81.18);
anal. calc. for C12H12Cl5O6P: C, 31.30, H, 2.63. Found: C, 31.41, H,
2.68%.
[7] H.W. He, Z.J. Liu, Chin. J. Org. Chem. 21 (2001) 878–883.
[8] J.L. Brayer, L. Talinani, J. Tessier, EP 376819, 1990.
[9] H. Mccommbie, B.C. Sauaders, J. Chem. Soc. (1945) 380–382.
[10] 6a: O,O-dimethyl 1-(2,3-dichlorophenoxyacetoxy)ethylphosphonate,
oil, n2D0 1.5131; 1H NMR (400 Hz, CDCl3) d: 1.48–1.54 (d, 3H,
CH3), 3.76–3.84 (m, 6H, 2OCH3), 4.80(s, 2H, OCH2CO), 5.38–5.47
(m, 1H, OCHP, JHP = 13.3 Hz), 6.79–7.17 (m, 3H, C6H3); IR (KBr)
(cmÀ1): 3077 (Ar–H), 1748 (C O), 1264 (P O), 740 (P–C); EIMS
(probe) 70 eV, m/z (rel. int.): 356 [M]+ (41.55), 138 (91.87), 109 (100),
93 (69.22); anal. calc. for C12H15Cl2O2P: C, 40.36, H, 4.23. Found: C,
40.38, H, 4.10%. 6b: O,O-dimethyl 1-(2,3-dichlorophenoxyacetoxy)tri-
chloromethylmethylphosphonate, oil, n2D0 1.5392; 1H NMR (400 Hz,
[11] A.H. Lu, W.H. He, J. Central. Cina. Normal. University (Nat. Sci.) 33 (4)
(1999) 543–546.
[12] L.P. Meng, H.W. He, Z.J. Liu, HuBeiHuaGong (special issue) (1998) 40–
41.
[13] H.W. He, T. Chen, T. Wang, CN 1560058A, 2005.
[14] F. Texier-Boullet, M. Leouitte, Tetrahedron Lett. 27 (30) (1986) 3515–
3516.
[15] F. Texier-Boullet, A. Foucaud, Synthesis 11 (1982) 916–918.