Nucleophilic fluorination of α-aroylphosphinates with morpholinosulfur trifluoride

Article abstract of DOI:10.1002/hc.21171

Nucleophilic fluorination of aroyl-phenyl-phosphinates is highly dependent on the nature of the alkoxy substituents attached to the phosphoryl group. A reaction of aroyl-phenyl-phosphinates with morpholinosulfur trifluoride was shown to be a convenient synthetic method for high-yield synthesis of α,α-difluorobenzyl-phenyl-phosphinates using steric protection of the phosphoryl group by a bulky isopropoxy substituent. The methyl esters of aroylphosphinic acids in the same reaction conditions yield (fluoro-diaryl- methyl)-pentafluorophosphates as the main reaction products.

Full text of DOI:10.1002/hc.21171

Heteroatom Chemistry
Volume 25, Number 4, 2014
Nucleophilic Fluorination of
α-Aroylphosphinates with Morpholinosulfur
Trifluoride
Sergiy V. Zasukha, Olexandr I. Guzyr, and Yuriy G. Shermolovich
Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 02094, Kiev, Ukraine
Received 11 February 2014; revised 15 April 2014
and efficient substances for safe neutralization of
ABSTRACT: Nucleophilic fluorination of aroyl-
organophosphorus chemicals in vivo [2]. One of the
phenyl-phosphinates is highly dependent on the na-
procedures for the synthesis of such compounds is
ture of the alkoxy substituents attached to the phos-
fluorination of α-oxophosphinates by dialkylamino
phoryl group. A reaction of aroyl-phenyl-phosphinates
sulfur trifluoride (DAST). However, only one exam-
with morpholinosulfur trifluoride was shown to be
ple of such a reaction is reported in the literature
a convenient synthetic method for high-yield syn-
(Scheme 1). Thus, the fluorination of 1 gave di-
thesis of α,α-difluorobenzyl-phenyl-phosphinates us-
fluoromethylenephosphinate 2 in low yield (22%).
ing steric protection of the phosphoryl group by a
All attempts to fluorinate other ethyl aroylphos-
bulky isopropoxy substituent. The methyl esters of
phinates 3 yielded only degradation products.
aroylphosphinic acids in the same reaction conditions
This observation allowed authors to conclude the
yield (fluoro-diaryl-methyl)-pentafluorophosphates as
ineffectiveness of the nucleophilic fluorination for
ꢀC
the main reaction products.
2014 Wiley Periodi-
the synthesis of α,α-difluoromethylenephosphinates
[2].
cals, Inc. Heteroatom Chem. 25:256–264, 2014; View
this article online at wileyonlinelibrary.com. DOI
10.1002/hc.21171
We found in our previous work that nucleophilic
fluorination of α-oxophosphonates is highly depen-
dent on the nature of the substituents attached
to the carbonyl and alkoxy groups [3]. Thus, the
main product of the fluorination of dimethyl ben-
zoylphosphonate 4a with morpholinosulfur trifluo-
ride (MOST) is (morpholino)(phenyl)methylidene-
pentafluorophosphate 5, which is isostructural to
the adduct of (morpholino)(phenyl)carbene with
phosphorus pentafluoride. The replacement of the
methoxy group with a bulky isopropoxy sub-
stituent (Scheme 2) allows to obtain diisopropyl α,α-
difluorobenzylphosphonate 6b as a main product
(isolated yield 63%).
The aim of the present work was to inves-
tigate nucleophilic fluorination of aroyl-phenyl-
phosphinates in detail and study the influence of
the nature of alkoxy substituents in the molecules of
α-oxophosphinates on the structure of the product(s)
in their reaction with MOST.
INTRODUCTION
The approaches to the synthesis of α,α-
difluoromethylenephosphonates as mimetics of
phosphates were investigated for a long time. This
is related to the known facts of significant improve-
ment of the biological activity of organophosphorus
compounds containing fluorinated substituents in
comparison with their nonfluorinated analogs [1].
At the same time, the methods for the prepara-
tion of α,α-difluoromethylenephosphinates were
rarely explored despite their importance as new
Correspondence to: Yuriy Shermolovich; e-mail: sherm@ioch.
kiev.ua.
ꢀC
2014 Wiley Periodicals, Inc.
256

Nucleophilic Fluorination of α-Aroylphosphinates with Morpholinosulfur Trifluoride 257
to the reaction mixture) takes place smoothly
O
FF
NO2
NO2
O
O
P
OEt
O
P
OEt
at 0°C and leads to α,α-difluorobenzyl-phenyl-
phosphinates 8a–e after the subsequent work-up in
low yields (14–32%). Taking into account our previ-
ous findings [3], we also expected that other reaction
products could be (aryl)(morpholino)methylidene-
phenyl-tetrafluorophosphates 10. However, con-
trary to our expectations, other compounds formed
during the reaction of 7a–e with MOST are
(diaryl-fluoro-methyl)-pentafluorophosphates 9a–e
(Scheme 3).
We suggest that the mechanism of the re-
action of 7a–k with MOST might be similar
to those proposed earlier for the fluorination of
dimethyl aroylphosphonates [3]. Thus, the fluori-
nation of the carbonyl group as an example of 7a
proceeds via the “classical” mechanism [4], which
includes the following steps: addition of HF (cat-
alyst) to the C O group, nucleophilic substitu-
tion the OH group in the intermediate 11 by
R2NSF3, and subsequent elimination of R2NS( O)F
yielding α,α-difluorobenzyl-phenyl-phosphinate 8a
(Scheme 4).
Et2NSF3
Et2NSF3
O
O
1
2
O
22 %
O
NO2
O
P
OEt
only degradation products
3
X
O
N
O
(CH3)3O-
X = H, F, O
O ,
SCHEME 1 Known examples of α-oxophosphinates fluori-
nation with DAST [2].
RESULTS AND DISCUSSION
It was found that the reaction of methyl esters of
aroyl-phenyl-phosphinic acids 7a–e with MOST in
dichloromethane as a solvent and in the presence of
HF (generated by addition of few drops of methanol
O
F F
PF5
O
OR
OR
O
OR
OR
R2NSF3
P
P
+
C
N
4a,b
5
6a,b
O
R2N =O
N-
4a: R = Me
4b: R = i-Pr
6a: 15 %
6b: 63 %
5: 54 %
5: –
SCHEME 2 Fluorination of benzoylphosphonates 4a,b with R2NSF3.
F
O
FF
O
P
OR'
O
P
OMe
X
PF5
R2NSF3
R' = Me
R2NH2
+
X
X
X
7a–k
8a–e
R2NSF3
9a–e
R' = i-Pr
FF
O
P
Oi-Pr
Me
i-Pr
R' =
X = H
X = Me
X = OMe
X = F
8a: 32%
8b: 19%
8c: 14%
8d: 22%
8e: 27%
8f: 56%
8g: 54%
8h: 66%
8i: 74%
8k: 72%
R2N =O
N-
8f–k
X = Cl
O
PF4
O
O
P
OR'
R2NSF3
X
R' = Me
X
C
N
X
7a–k
10
SCHEME 3 Reactions of aroyl-phenyl-phosphinates with R2NSF3.
Heteroatom Chemistry DOI 10.1002/hc

258 Zasukha, Guzyr, and Shermolovich
O
O
OH
FF
R2NSF3
-R2NS(=O)F
-HF
O
P
OMe
O
P
OMe
HF
P
F
OMe
7a
11
8a
SCHEME 4 Mechanism for the formation of 8a.
The formation of a second reaction product,
(fluoro-diphenyl-methyl)-pentafluorophosphate 9a,
should proceed in two alternative ways. First,
it might include fluorination of the phosphoryl
group in α,α-difluorobenzyl-phenyl-phosphinate 8a
(Scheme 5). To verify this assumption, we performed
the reaction of 8a with the excess of MOST in
dichloromethane in the presence of HF. However,
no reaction took place at normal conditions or after
the prolonged reflux in dichloromethane. Thus, in
our suggestion, the formation of compound 9a can
consist in realization of another tentative reaction
scheme: fluorination of the P O group that follows
independently with the C O group fluorination (re-
sulting in 8a; Scheme 5).
tion of 14 with HF and MOST results in an inter-
mediate 15. The transformation of 15 to tetrafluo-
rophosphorane 16 takes place by migration of the
phenyl group from phosphorus to the carbon atom
and elimination of R2NS( O)F. Finally, an interme-
diate 16 reacts with the morpholinium salt of HF,
giving compound 9a. The formation of the mor-
pholinium hydrogen fluoride salt takes place by
the reaction of R2NS( O)F with hydrogen fluoride,
which was present in the reaction mixture initially
and formed additionally by the reaction of MOST
with methanol.
It should be mentioned that observed transfor-
mations include a rare example of phenyl group mi-
gration from phosphorus to a carbon dyad [5] in
spite of the fact that phenyl group migration pro-
ceeds as by radical, so by the ionic mechanism is
well known and studied for the cases of migration in
dyads C C [6], Si C [7], and P N [8].
Thus, the consecutive HF-catalyzed fluorination
of the phosphoryl group in 7a results in the forma-
tion of benzoyltrifluorophosphorane 14. The reac-
The replacement of the methoxy groups
FF
in
with bulky isopropoxy (compounds 7f–k) re-
sults in significant increase in the yields
starting
aroyl-phenyl-phosphinates
7a–e
O
P
OMe
F
R2NSF3
X
PF5
[R2NH2]
a
of α,α-difluorobenzylphosphinates 8f–k (54–
74%). Only the traces of (fluoro-diaryl-methyl)-
pentafluorophosphates 9a–e were detected by 19F
NMR of the reaction mixtures in this case. This
fact demonstrates very well that fluorination of
carbonyl and phosphoryl groups is a competi-
tive process and could be influenced by blocking
of the reactive centers using sterically hindered
substituents located close to the phosphorus
atoms.
Novel α,α-difluorobenzyl-phenyl-phosphinates
8a–k were isolated by column chromatography as
colorless or pale yellow oily liquids and solids. The
details for the preparation of compounds 8a–k as
well as their spectroscopic and analytical data are
given in the Experimental section.
Compound 9a was isolated in the pure state as
a precipitate from the reaction mixture. The com-
position of 9a was confirmed on that basis of the
analytical and spectroscopic data. Thus, the 31P
NMR spectra showed the signals in high-field area
(–140.1 ppm) inherent to hexacoordinated phospho-
rus compounds. The 19F NMR spectra contain the
doublet at –151.2 ppm (2JFP = 98 Hz, aliphatic C F)
8a
9a
16
R2N =O
N-
[R2NH2]
F
NR2
F
F
S
O
F
PF4
-R2NS(=O)F
PF3
F
15
O
OSF2NR2
P
R2NSF3
HF
-HF
F
R2NSF3
HF
-2R2NS(=O)F
-MeF
-HF
OMe
O
13
F
P
R2NSF3
-HF
F
F
14
O
O
O
P
OMe
OH
P
F OMe
HF
7a
12
R2NSF3 + MeOH
R2NS(=O)F + 2HF
R2NS(=O)F + HF + MeF
R2NH2F + SOF2
SCHEME 5 Proposed mechanism for the formation of 9a.
Heteroatom Chemistry DOI 10.1002/hc

Nucleophilic Fluorination of α-Aroylphosphinates with Morpholinosulfur Trifluoride 259
EXPERIMENTAL
General
O
OH
F
Ph2C-PF5
H2O (exc.), RT
-3HF, -R2NH2F
Ph2C-P
[R2NH2]
F
9a
F
17
All experiments involving air-sensitive compounds
were performed under an inert atmosphere
(dry Ar) using standard Schlenk techniques.
Dichloromethane was freshly distilled over CaH2.
Aroylphosphinates 7a–k [9] and MOST [10] were
obtained according to the known procedures. 1H
(299.94 MHz), 13C (100.62 MHz), 19F (188.14 MHz),
and 31P (80.95 MHz) NMR spectra were recorded
on Varian VXR-300, Bruker Avance 400, and Var-
ian Gemini-200 spectrometers, respectively, at room
temperature. Chemical shift values were measured
relative to TMS (internal standard) and H3PO4 (ex-
ternal standard). 19F NMR spectra were recorded
using C6F6 as an internal standard, and the chem-
ical shifts were converted into an δ scale relative to
CCl3F. MS analyses were carried out using an Ali-
gent 1100 series HPLC system equipped with a diode
matrix and an Aligent LC/MSD SL mass selective de-
tector (ionization method: API-ES). Infrared spectra
were recorded on a Bruker Vertex 70 spectrometer
equipped with ATR accessory. Melting points values
were determined on a Boetius device and are un-
corrected. Silica gel Merck 60 (0.063–0.2 μm) was
used for chromatography. Thin layer chromatogra-
phy was carried out using precoated plastic plates
(PolygramꢀR Sil G/UV254) visualized by UV light or
by a I2 vapor. Elemental analyses were performed
at the microanalytical laboratory of the Institute of
Organic Chemistry, National Academy of Sciences
of Ukraine.
H2O (exc.), reflux
-2HF
O
Ph2C-P(OH)2
OH
18
SCHEME 6 Hydrolyses of 9a.
and the group of signals characteristic for the PF5
1
substituent [δ –63.1 (1F, dquint, JFaxP = 674 Hz,
2JFaxFeq = 40 Hz), –61.4 (4F, ddd, JFeqP = 891.5 Hz,
1
2JFeqFax = 40 Hz, 3JFF = 8.1 Hz)]. The 1H NMR spec-
tra of compound 9a show the presence of NH group,
aromatic protons, and morpholine group with the
correct integration (2:10:8).
The formation of the other (fluoro-diaryl-
methyl)-pentafluorophosphates 9b–e was evidenced
by monitoring of the reaction mixtures by 31P and
19F NMR techniques. The chemical shifts and the
coupling constants in 19F and 31P NMR for com-
pounds 9b–e are similar to the values observed for
compound 9a. However, owing to their high solubil-
ity in CH2Cl2 and sensitivity to hydrolyses, we were
not able to isolate them in the pure state after an
usual water work-up procedure. Moreover, to ver-
ify definitely the fact of phosphorus-carbon phenyl
group migration, we performed stepwise NMR con-
trolled hydrolyses of 9a, which yielded previously de-
scribed (hydroxy-diphenyl-methyl)-phosphonic acid
18 containing two equivalent phenyl groups at-
tached to the carbon atom as the final product
(Scheme 6).
Preparation of
(α,α,-Difluoro-benzyl)-phosphonic Acid
Diisopropyl Ester (6b)
MOST (1.86 g) was added portionwise at 0°C over the
period of 9 h to a stirred solution of 4b (0.63 g) in dry
CH2Cl2 (3 mL) and MeOH (1 drop, for formation of
HF as a catalyst). The reaction mixture was stirred
overnight at 25°C and washed with H2O (3 × 20 mL
until the neutral pH of a water layer). An organic
layer was separated, dried with Na2SO4, and evapo-
rated in a vacuum, giving 6b as a pale yellow oil. A
crude product was purified by column chromatogra-
phy using CH2Cl2 as an eluent. Yield: 0.43 g (63%).
CONCLUSIONS
In conclusion, we have shown that the products
of the reaction between aroyl-phenyl-phosphinates
and MOST are highly dependent on the na-
ture of alkoxy substituents. Nucleophilic fluori-
nation of aroyl-phenyl-phosphinates can be used
as a convenient synthetic method for high-yield
synthesis of the corresponding α,α-difluorobenzyl-
phenyl-phosphinates using steric protection of the
phosphoryl group by the bulky isopropoxy sub-
stituent. The methyl esters of aroylphosphinic
acids in the same reaction conditions give (fluoro-
diaryl-methyl)-pentafluorophosphates as the main
products.
1
Rf = 0.33 (СH2Cl2). H NMR (299.94 MHz, CDCl3,
ppm): δ 1.25 (3H, d, 3JHH = 5.7 Hz, CH3), 1.35 (3H, d,
3JHH = 6 Hz, CH3), 4.76 (2H, m, CH), 7.44–7.64 (5H,
m, Haro); 31P NMR (80.95 MHz, CH2Cl2, ppm): δ 4.73
(t, 2JPF = 112 Hz); 19F NMR (188.143 MHz, CH2Cl2,
ppm): δ –109.57 (d, 2JFP = 112 Hz); 13C (100.62 MHz,
CDCl3, ppm): δ 23.5 (d, 3JCP = 5.4 Hz, CH3), 24.1 (d,
Heteroatom Chemistry DOI 10.1002/hc

260 Zasukha, Guzyr, and Shermolovich
2
3
3
3JCP = 3.6 Hz, CH3), 73.8 (d, JCP = 7.3 Hz, CH),
24.2 (d, JCP = 4.7 Hz, CH3), 24.4 (d, JCP = 3.7 Hz,
1
1
2
117.9 (td, JCF = 262.9 Hz, JCP = 219.9 Hz, CF2),
CH3), 55.6 (s, CH3O), 72.1 (d, JCP = 7.4 Hz, CH),
3
3
2
126.4 (td, JCF = 6.9 Hz, JCP = 2.2 Hz, Caro), 128.2
(s, Caro), 130.6 (m, Caro), 132.9 (m, Caro). IR (KBr),
cm−1: 1260 (P O). MS m/z (%): 208.9 (free phospho-
nic acid) (100) [M+]. Anal. Calcd for C13H19F2O3P:
C, 53.42; H, 6.55; P, 10.60. Found: C, 53.22; H, 6.38;
P, 10.51.
114.1 (s, Caro), 128.5 (d, JCP = 12.5 Hz, Caro), 128.7
1
2
(d, JCP = 128.3 Hz, Caro), 129.6 (d, JCP = 56.2 Hz,
2
Caro), 132.5 (d, JCP = 9.6 Hz, Caro), 132.7 (s, Caro),
132.9 (d, 3JCP = 2.8 Hz, Caro), 164.8 (s, Caro), 199.6 (d,
1JCP = 119 Hz, C = O). IR (KBr), cm−1: 1591 (C = O),
1242 (P = O). Anal. Calcd for C17H19O4P: C, 64.15;
H, 6.02; P, 9.73. Found C, 64.09; H, 5.98; P, 9.56.
Aroylphosphinates 7a–k [9] and MOST [10]
were obtained according to the known procedures.
Aroylphosphinates 7d and 7f–7k have not been re-
ported in the literature. The spectroscopic and ana-
lytical data for these compounds are given below.
(4-Methyl-benzoyl)-phenyl-phosphinic Acid Iso-
propyl Ester (7g). Yield: 68%, mp 70°С (hexane).
1H NMR (299.94 MHz, CDCl3, ppm): δ 1.36 (3H, d,
3JHH = 6.0 Hz, CH3), 1.45 (3H, d, 3JHH = 6.0 Hz, CH3),
2.41 (3H, s, CH3), 4.79 (1H, m, CH), 7.28–8.33 (9H,
m, Haro). 31P NMR (80.95 MHz, CDCl3, ppm): δ 20.53
(4-Fluoro-benzoyl)-phenyl-phosphinic
Acid
Methyl Ester (7d). Yield: 37%, mp 115°С (Et2O).
1H NMR (299.94 MHz, CDCl3, ppm): δ 3.90 (3H,
(m, JPH = 6.0 Hz). 13C (100.62 MHz, CDCl3, ppm):
3
3
3
d, JHP = 11.4 Hz, OCH3), 7.13–8.48 (9H, m, Haro).
δ 21.8 (s, CH3-Caro), 24.2 (d, JCP = 4.3 Hz, CH3),
31P NMR (80.95 MHz, CH2Cl2, ppm): δ 22.4 (m).
19F NMR (188.143 MHz, CH2Cl2, ppm): δ –102.46
(s, F Caro). 13C (100.62 MHz, CDCl3, ppm): δ 52.6
24.3 (d, JCP = 3.8 Hz, CH3), 72.1 (d, JCP = 7.3 Hz,
3
2
CH), 128.5 (d, 1JCP = 128.7 Hz, Caro), 128.5 (d, 2JCP
=
13.3 Hz, Caro), 129.5 (s, Caro), 130.1 (s, Caro), 132.5
2
2
(d, JCP = 7.4 Hz, OCH3), 116.2 (d, JCF = 22.1 Hz,
(d, 2JCP = 9.8 Hz, Caro), 132.9 (d, 3JCP = 3.2 Hz, Caro),
Caro), 126.8 (d, 1JCP = 129 Hz, Caro), 128.8 (d, 3JCF
=
133.7 (d, JCP = 54.4 Hz, Caro), 145.8 (s, Caro), 201.3
2
13.8 Hz, Caro), 132.45 (d, 2JCP = 55.5 Hz, Caro), 132.5
(d, JCP = 117.8 Hz, C=O). IR (KBr), cm−1: 1596
1
3
2
(d, JCP = 9.8 Hz, Caro), 133.0 (d, JCP = 9.6 Hz,
(C=O), 1232 (P=O). Anal. Calcd for C17H19O3P: C,
67.54; H, 6.33; P, 10.25. Found: C, 67.48; H, 6.30; P,
10.11.
3
1
Caro), 133.5 (d, JCP = 2.4 Hz, Caro), 166.6 (d, JCF
=
258.7 Hz, Caro), 199.6 (d, 1JCP = 118.5 Hz, C O). IR
(KBr), cm−1: 1589 (C O), 1228 (P O). Anal. Calcd
for C14H12FO3P: C, 60.44; H, 4.35; P, 11.13. Found:
C, 60.34; H, 4.39; P, 11.10.
(4-Fluoro-benzoyl)-phenyl-phosphinic Acid Iso-
propyl Ester (7i). Yield: 46%, mp 76°С (Et2O). H
1
NMR (299.94 MHz, CDCl3, ppm): δ 1.36 (3H, d,
3
Benzoyl-phenyl-phosphinic Acid Isopropyl Ester
(7f). Yield: 36%, mp 70°С, bp 146°С (0.03 Torr).
1H NMR (299.94 MHz, CDCl3, ppm): δ 1.36 (3H, d,
3JHH = 5.9 Hz, CH3), 1.46 (3H, d, 3JHH = 5.9 Hz, CH3),
4.80 (1H, m, CH), 7.26–8.42 (10H, m, Haro). 31P NMR
(80.95 MHz, CH2Cl2, ppm): δ 20.37 (m). 13C (100.62
3JHH = 6.1 Hz, CH3), 1.46 (3H, d, JHH = 6.1 Hz,
CH3), 4.79 (1H, m, CH), 7.10–8.51 (9H, m, Haro).
31P NMR (80.95 MHz, CH2Cl2, ppm): δ 20.03 (m).
19F NMR (188.143 MHz, C6H6, ppm): δ -100.8 (s,
F-Caro); 13C (100.62 MHz, CDCl3, ppm): δ 24.3 (d,
3JCP = 4.6 Hz, CH3), 24.4 (d, JCP = 4.2 Hz, CH3),
3
3
MHz, CDCl3, ppm): δ 24.29 (d, JCP = 4.8 Hz, CH3),
72.5 (d, 2JCP = 7.3 Hz, CH), 116.1 (d, 2JCF = 22.8 Hz,
24.41 (d, 3JCP = 3.7 Hz, CH3), 72.4 (d, 2JCP = 7.1 Hz,
Caro), 128.2 (d, 1JCP = 130.6 Hz, Caro), 128.6 (d, 3JCF
=
CH), 128.3 (d, 1JCP = 129.6 Hz, Caro), 128.6 (d, 2JCP
=
13.4 Hz, Caro), 132.6 (d, JCP = 10.2 Hz, Caro), 132.7
3
2
2
12.4 Hz, Caro), 128.9 (s, Caro), 130.0 (s, Caro), 132.6 (d,
(d, JCP = 55.9 Hz, Caro), 133.0 (d, JCP = 9.5 Hz,
3
3
1
3JCP = 10.3 Hz, Caro), 133.1 (d, JCP = 2.8 Hz, Caro),
Caro), 133.2 (d, JCP = 2.8 Hz, Caro), 166.6 (d, JCF =
2
134.7 (s, Caro), 136.0 (d, JCP = 54.4 Hz), 202.1 (d,
258.3 Hz, Caro), 200.5 (d, 1JCP = 119.7 Hz, C=O). IR
(KBr), cm−1: 1591 (C=O), 1235 (P=O). Anal. Calcd
for C16H16FO3P: C, 62.75; H, 5.27; P, 10.11. Found:
C, 62.69; H, 5.22; P 10.05.
1JCP = 119 Hz, C O). IR (KBr), cm−1: 1646 (C O),
1228 (P O). Anal. Calcd for C16H17O3P: C, 66.66; H,
5.25; P, 10.74. Found C, 66.45; H, 5.17; P, 10.61.
(4-Methoxy-benzoyl)-phenyl-phosphinic Acid Iso-
propyl Ester (7h). Yield: 51%, bp 175°С (0.015 Torr).
1H NMR (299.94 MHz, CDCl3, ppm): δ 1.36 (3H, d,
(4-Chloro-benzoyl)-phenyl-phosphinic Acid Iso-
propyl Ester (7k). Yield: 37%, mp 80°С (Et2O). H
1
NMR (299.94 MHz, CDCl3, ppm): δ 1.36 (3H, d,
3JHH = 6.0 Hz, CH3), 1.46 (3H, d, 3JHH = 6.3 Hz, CH3),
4.79 (1H, m, CH), 7.27–8.40 (9H, m, Haro). 31P NMR
(80.95 MHz, CDCl3, ppm): δ 19.88 (m). 13C (100.62
3
3JHH = 6.0 Hz, CH3), 1.45 (3H, d, JHH = 6.0 Hz,
CH3), 3.88 (3H, s, OCH3), 4.78 (1H, m, CH), 6.94–
8.46 (9H, m, Haro). 31P NMR (80.95 MHz, CH2Cl2,
ppm): δ 20.32 (m). 13C (100.62 MHz, CDCl3, ppm): δ
3
MHz, CDCl3, ppm): δ 24.3 (d, JCP = 4.5 Hz, CH3),
Heteroatom Chemistry DOI 10.1002/hc

Nucleophilic Fluorination of α-Aroylphosphinates with Morpholinosulfur Trifluoride 261
3
2
59.58; H, 4.64; P, 10.97. Found: C, 59.49; H, 4.60; P,
10.94.
24.4 (d, JCP = 4.0 Hz, CH3), 72.5 (d, JCP = 7.1 Hz,
CH), 128.0 (d, 1JCP = 128.7 Hz, Caro), 128.6 (d, 2JCP
=
13.1 Hz, Caro), 129.3 (s, Caro), 131.4 (s, Caro), 132.6 (d,
2JCP = 10.1 Hz, Caro), 133.2 (d, JCP = 2.8 Hz, Caro),
3
Morpholinium Salt of (Fluoro-diphenyl-methyl)-
2
pentafluorophosphate (9a). Yield: 0.48 g (31%). Col-
orless solid, mp 115°C. 1H NMR (299.94 MHz,
DMSO-d6, ppm): δ 3.10 (4H, m, CH2), 3.75 (4H, m,
CH2), 7.06–7.54 (10H, m, Haro), 8.72 (2H, s, br, NH2);
31P NMR (80.95 MHz, acetone, ppm): δ –140.1 (qdd,
1JPFax = 891.5 Hz, 1JPFeq = 674.1 Hz, 2JPF = 98.3 Hz);
19F NMR (188.14 MHz, acetone, ppm): δ -151.2 (1F,
134.4 (d, JCP = 55.6 Hz, Caro), 141.3 (s, Caro), 201.1
(d, JCP = 119.5 Hz, C=O). IR (KBr), cm−1: 1583
1
(C=O), 1234 (P=O). Anal. Calcd for C16H16ClO3P: C,
59.55; H, 5.00; P, 9.60. Found: C, 59.47; H, 4.93; P,
9.51.
dm, 2JFP = 98.3 Hz, FC), –63.13 (1F, dquint, 1JFaxP
=
General Procedure for the Reactions of Methyl
Aroyl-phenyl-phosphinates (7a–e) with MOST
2
674.1 Hz, JFaxFeq = 40.4 Hz, Fax), –61.4 (4F, ddd,
2
3
1JFeqP = 891.5 Hz, JFeqFax = 40.4 Hz, JFF = 8.1 Hz,
MOST was added dropwise at 0°C over the period
of 9 hours to stirred solution of 1 in dry CH2Cl2
and MeOH (1 drop, for formation of HF as a cat-
alyst). The reaction mixture was stirred overnight
at 25°C. For the further experimental details for
work-up of each compound, see the description
below.
Feq); 13C (100.62 MHz, DMSO-d6, ppm): δ 43.1 (s,
CH2), 63.6 (s, CH2), 125.3 (s, Caro), 126.3 (dm, 2JCP
=
=
2
13.5 Hz, Caro), 126.6 (s, Caro), 146.5 (d, br, JCF
21.7 Hz, Caro), CFPF5: not observed.
[α,α-Difluoro-(4-methyl-benzyl)]-phenyl-
phosphinic Acid Methyl Ester (8b). Compound
8b was obtained from 7b (0.65 g, 2.34 mmol) in
CH2Cl2 (3 mL) and MOST (1.26 g, 7.19 mmol).
The reaction mixture was washed with H2O
(3 × 20 mL, until the neutral pH of the water
layer). The organic layer was separated, dried
with Na2SO4, and evaporated in a vacuum. The
residue was washed with Et2O (3 × 10 mL).
The combined ether extracts were evaporated,
giving 8b as a pale yellow oil. The crude product
was purified by column chromatography (graduate
elution, from CH2Cl2 to EtOAc as eluents). Yield:
Details for the Preparation of the Compounds 8a
and 9a. Compound 8a and 9a were obtained from
7a (1 g, 3.84 mmol) in CH2Cl2 (5 mL) and MOST
(2.4 g, 13.7 mmol). The precipitate from the reac-
tion mixture was filtered, washed with water (4 ×
10 mL), and dried in a vacuum giving 9a as a col-
orless solid. The filtrate was washed with H2O (3 ×
20 mL, until the neutral pH of the water layer). The
organic layer was separated, dried with Na2SO4, and
evaporated in a vacuum. The residue was washed
with Et2O (3 × 5 mL). The combined ether extracts
were evaporated giving 8a as a pale yellow oil. The
crude product was purified by column chromatog-
raphy (graduate elution, from CH2Cl2 to EtOAc as
eluents).
1
0.13 g (19%). Rf = 0.24 (CH2Cl2), H NMR (299.94
MHz, CDCl3, ppm): δ 2.38 (3H, s, CH3-Caro), 3.79
3
(3H, d, JHP = 10.5 Hz, CH3), 7.21–7.83 (9H, m,
Haro); 31P NMR (80.95 MHz, CDCl3, ppm): δ 28,42
2
(t, JPF = 108.3 Hz); 19F NMR (188.143 MHz,
2
2
CDCl3, ppm): δ –108.4 (dd, JFF = 302.4 Hz, JFP
=
=
2
2
(α,α-Difluoro-benzyl)-phenyl-phosphinic
Acid
108.3 Hz), −107.8 (dd, JFF = 302.4 Hz, JFP
Methyl Ester (8a). Yield: 0.35 g (32%). Rf = 0.17
108.3 Hz). 13C (100.62 MHz, CDCl3, ppm): δ 21.4
2
(CH2Cl2). 1H NMR (299.94 MHz, CDCl3, ppm): δ
(s, CH3-Caro), 53.2 (d, JCP = 6.8 Hz, CH3), 119.6
3
1
1
3.81 (3H, d, JHP = 10.5 Hz, CH3), 7.40–7.82 (10H,
(td, JCF = 267.3 Hz, JCP = 154.3 Hz, CF2), 124.9
1
3
m, Haro); 31P NMR (80.95 MHz, CDCl3, ppm): δ
(d, JCP = 135.9 Hz, Caro), 126.4 (td, JCF = 6.7 Hz,
2
28.01 (t, JPF = 107.7 Hz); 19F NMR (188.143 MHz,
3JCP = 1.5 Hz, Caro), 128.6 (d, JCF = 13.2 Hz, Caro),
2
3
CH2Cl2, ppm): δ –108.4 (dd, 2JFP = 107.7 Hz, 2JFF
=
=
128.9 (m, Caro), 129.0 (s, Caro), 133.2 (d, JCP
=
2
2
302.4 Hz), −107.8 (dd, JFP = 107.7 Hz, JFF
10 Hz, Caro), 133.7 (d, JCP = 3.0 Hz), 141.0 (m, Caro).
IR (KBr), cm−1: 1248 (P O). MS m/z (%): 296.1
(100) [M+]. Anal. Calcd for C15H15F2O2P: C, 60.81;
H, 5.10; P, 10.46. Found: C, 60.74; H, 5.08; P, 10.41.
302.4 Hz). 13C (100.62 MHz, CDCl3, ppm): δ 53.1
2
1
(d, JCP = 7.0 Hz, CH3), 119.5 (td, JCF = 266.4 Hz,
1JCP = 153.5 Hz, CF2), 124.7 (d, JCP = 136.0 Hz,
1
3
3
Caro), 126.4 (td, JCF = 6.7 Hz, JCP = 1.6 Hz Caro),
2
128.3 (s, Caro), 128.6 (d, JCF = 13.2 Hz, Caro), 130.7
[α,α-Difluoro-(4-methoxy-benzyl)]-phenyl-
2
2
(m, Caro), 132.0 (td, JCF = 21 Hz, JCP = 12 Hz,
phosphinic Acid Methyl Ester (8c). Compound
8c was obtained from 7c (0.68 g, 2.34 mmol)
in CH2Cl2 (3 mL) and MOST (1.94 g, 11.07
mmol). The reaction mixture was evaporated in a
3
3
Caro), 133.2 (d, JCP = 9.6 Hz, Caro), 133.8 (d, JCP
=
3.0 Hz). IR (KBr), cm−1: 1246 (P O). MS m/z (%):
283.0 (100) [M+]. Anal. Calcd for C14H13F2O2P: C,
Heteroatom Chemistry DOI 10.1002/hc

262 Zasukha, Guzyr, and Shermolovich
vacuum. The residue was washed with hexane (3
× 10 mL). The combined hexane extracts were
evaporated giving 8c as a pale yellow oil. The crude
product was washed with H2O (3 × 20 mL). The
organic layer was separated, dried with Na2SO4,
was purified by column chromatography (graduate
elution, from CH2Cl2 to EtOAc as eluents). Pale
yellow solid. Yield 0.2 g (27%), mp 88°C. Rf = 0.33
(CH2Cl2). 1H NMR (299.94 MHz, CDCl3, ppm): δ
3
3.82 (3H, d, JHP = 10.2 Hz, CH3), 7.27–7.82 (9H,
and evaporated in a vacuum. Yield 0.1 g (14%). 31P
m, Haro). 31P NMR (80.95 MHz, CH2Cl2, ppm): δ
2
2
NMR (80.95 MHz, hexane, ppm): δ 27,50 (t, JPF
=
26.79 (t, JPF = 107.3 Hz). 19F NMR (188.143 MHz,
110.4 Hz). 19F NMR (188.143 MHz, CH2Cl2, ppm): δ
–107.3 (dd, 2JFF = 298.2 Hz, 2JFP = 110.4 Hz), –106.4
(dd, 2JFF = 298.2 Hz, 2JFP = 110.4 Hz). Owing to the
CH2Cl2, ppm): δ –108.6 (dd, 2JFF = 303.7 Hz, 2JFP
=
=
2
2
107.3 Hz), –108.0 (dd, JFF = 303.7 Hz, JFP
107.3 Hz). 13C (100.62 MHz, CDCl3, ppm): δ 53.2
1
2
1
high sensitivity of compound 8c to hydrolysis, H
(d, JCP = 6.9 Hz, CH3), 119.1 (td, JCF = 267 Hz,
and 13C NMR spectra were not obtained. MS m/z
1JCP = 154.6 Hz, CF2), 124.5 (d, JCP = 135.7 Hz,
1
(%): 313.0 (100) [M+].
Caro), 126.4 (td, JCF = 6.6 Hz, JCP = 1.5 Hz Caro),
3
3
2
127.3 (s, Caro), 128.7 (d, JCP = 13.6 Hz, Caro), 130.6
3
[α,α,-Difluoro-(4-fluoro-benzyl)]-phenyl-
(m, Caro), 133.2 (d, JCP = 9.8 Hz, Caro), 133.9 (d,
phosphinic Acid Methyl Ester (8d). Compound
8d was obtained from 7d (0.65 g, 2.34 mmol) in
CH2Cl2 (3 mL) and MOST (1.62 g, 9.25 mmol). The
reaction mixture was evaporated in a vacuum. The
residue was washed with hexane (3 × 10 mL).
The combined hexane extracts washed with H2O (3
× 20 mL). The organic layer was separated, dried
with Na2SO4, and evaporated in a vacuum giving 8d
as a pale yellow oil. The crude product was purified
by column chromatography (graduate elution, from
CH2Cl2 to EtOAc as eluents). Yield 0.15 g (22%).
Colorless solid, mp 70°C. Rf = 0.29 (CH2Cl2). 1H
NMR (299.94 MHz, CDCl3, ppm): δ 3.82 (3H, d,
3JCP = 2.2 Hz), 137.1 (m, Caro). IR (KBr), cm−1
:
1249 (P O). MS m/z (%): 317.2 (100) [M+]. Anal.
Calcd for C14H12ClF2O2P: C, 53.10; H, 3.82; P, 9.78.
Found: C, 53.06; H, 3.79; P, 9.71.
General Procedure for the Preparation of the
Compounds 8f–k
MOST was added dropwise at 0°C over the period
of 9 h to a stirred solution of 8 in dry CH2Cl2 and
MeOH (1 drop, for formation of HF as a catalyst).
The reaction mixture was stirred overnight at 25°C.
The reaction mixture was washed with H2O (3 ×
20 mL until the neutral pH of the water layer). The
organic layer was separated, dried with Na2SO4, and
evaporated in a vacuum, giving 8f–k as a pale yel-
low oils. The crude product was purified by column
chromatography (graduate elution, from CH2Cl2 to
EtOAc as eluents).
3JHP = 10.5 Hz CH3), 7.10–7.82 (9H, m, Haro). 31P
2
NMR (80.95 MHz, CH2Cl2, ppm): δ 27.2 (t, JPF
=
114.4 Hz); 19F NMR (188.143 MHz, CH2Cl2, ppm):
2
δ -109.1 (s, F-Caro), −107.8 (dd, JFP = 114.4 Hz,
2JFF = 303.0 Hz), −107.5 (dd, 2JFP = 114.4 Hz, 2JFF
=
303.0 Hz); 13C (100.62 MHz, CDCl3, ppm): δ 53.2
2
3
(d, JCP = 6.7 Hz, CH3), 115.6 (dd, JCF = 22.1 Hz,
3JCP = 1.5 Hz, Caro), 119.2 (td, JCF = 266 Hz,
(α,α-Difluoro-benzyl)-phenyl-phosphinic
Acid
1
1JCP = 155.6 Hz, CF2), 124.7 (d, JCP = 134.7 Hz,
Isopropyl Ester (8f). Compound 8f was obtained
from 7f (0.50 g, 1.73 mmol) in CH2Cl2 (3 mL) and
MOST (0.76 g, 4.34 mmol). Pale yellow oil. Yield
1
3
Caro), 128.1 (m, Caro), 128.7 (d, JCF = 13.3 Hz,
3
Caro), 128.8 (m, Caro), 133.2 (d, JCF = 9.8 Hz, Caro),
4
1
1
133.9 (d, JCF = 2.9 Hz), 164.2 (d, JCF = 251.1 Hz,
Caro). IR (KBr), cm−1: 1239 (P=O). MS m/z (%):
301.0 (100) [M+]. Anal. Calcd for C14H12F3O2P: C,
56.01; H, 4.03; P, 10.32. Found: C, 56.22; H, 4.12;
P, 10.21.
0.3 g (56%). Rf = 0.33 (CH2Cl2). H NMR (299.94
3
MHz, CDCl3, ppm): δ 1.21 (3H, d, JHH = 6.8 Hz,
3
CH3), 1.24 (3H, d, JHH = 6.8 Hz, CH3), 4.70 (1H,
m, CH), 7.29–7.75 (10H, m, Haro). 31P NMR (80.95
2
MHz, CH2Cl2, ppm): δ 24.8 (t, JPF = 105.6 Hz). 19F
NMR (188.143 MHz, CH2Cl2, ppm): δ –109.1 (dd,
2
2
[α,α-Difluoro-(4-chloro-benzyl)]-phenyl-
2JFF = 298 Hz, JFP = 105.6 Hz), –108.5 (dd, JFF
=
2
phosphinic Acid Methyl Ester (8e). Compound
8e was obtained from 7e (0.69 g, 2.34 mmol) in
CH2Cl2 (3 mL) and MOST (1.65 g, 9.42 mmol). The
reaction mixture was evaporated in a vacuum. The
residue was washed with Et2O (3 × 10 mL).
The combined ether extracts were washed with
H2O (3 × 20 mL). The organic layer was separated,
dried with Na2SO4, and evaporated in a vacuum,
giving 8e as a pale yellow solid. The crude product
298 Hz, JFP = 105.6 Hz); 13C (100.62 MHz, CDCl3,
ppm): δ 23.9 (d, 3JCP = 4.3 Hz, CH3), 24.4 (d, 3JCP
=
2
3.5 Hz, CH3), 72.7 (d, JCP = 7.2 Hz, CH), 119.5
1
1
(td, JCF = 266.3 Hz, JCP = 153.1 Hz, CF2), 126.5
1
3
(d, JCP = 134.6 Hz, Caro), 126.6 (td, JCF = 6.8 Hz,
2
JCP = 1.6 Hz, Caro), 128.2 (s, Caro), 128.4 (d, JCP
=
13.2 Hz, Caro), 130.6 (m, Caro), 132.2 (m, Caro), 133.2
(d, 2JCP = 9.6 Hz, Caro), 133.4 (d, JCP = 3.0 Hz, Caro).
IR (KBr), cm−1: 1244 (P O). MS m/z (%): 311.1
Heteroatom Chemistry DOI 10.1002/hc

Nucleophilic Fluorination of α-Aroylphosphinates with Morpholinosulfur Trifluoride 263
(100) [M+]. Anal. Calcd for C16H17F2O2P: C, 61.94;
[α,α-Difluoro-(4-fluoro-benzyl)]-phenyl-
H, 5.52; P, 9.98. Found: C, 61.87; H, 5.50; P, 9.93.
phosphinic Acid Isopropyl Ester (8i). Compound
8i was obtained from 7i (0.71 g, 2.32 mmol) in
CH2Cl2 (3 mL) and MOST (1.23 g, 7.02 mmol).
Yield: 0.56 g (74%). Pale yellow oil. Rf = 0.15
(CH2Cl2). 1H NMR (299.94 MHz, CDCl3, ppm): δ
1.31 (6H, m, CH3), 4.80 (1H, m, CH), 7.05–7.82 (9H,
m, Haro). 31P NMR (80.95 MHz, CH2Cl2, ppm): δ
[α,α-Difluoro-(4-methyl-benzyl)]-phenyl-
phosphinic Acid Isopropyl Ester (8g). Compound
8g was obtained from 7g (0.71 g, 2.36 mmol) in
CH2Cl2 (3 mL) and MOST (1.71 g, 9.76 mmol).
Yield: 0.41 g (54%). Colorless solid, mp 45°C. Rf =
0.29 (CH2Cl2). 1H NMR (299.94 MHz, CDCl3, ppm):
2
25.8 (t, JPF = 106.7 Hz). 19F NMR (188.143 MHz,
CDCl3, ppm): δ –109.7 (1F, s, F-Caro), –109.3 (1F,
3
2
2
δ 1.28 (3H, d, JHH = 5.8 Hz, CH3), 1.30 (3H, d,
dd, JFF = 301.9 Hz, JFP = 106.7 Hz), –108.7 (1F,
2 2
3JHH = 5.9 Hz, CH3), 2.37 (3H, s, CH3), 4.78 (1H,
dd, JFF = 301.9 Hz, JFP = 106.7 Hz,). 13C (100.62
3
m, CH), 7.17–7.83 (9H, m, Haro). 31P NMR (80.95
MHz, CDCl3, ppm): δ 23.9 (d, JCP = 4.4 Hz, CH3),
2
3
2
MHz, CDCl3, ppm): δ 25.10 (t, JPF = 116.2 Hz).
24.4 (d, JCP = 3.4 Hz, CH3), 72.8 (d, JCP = 7.4 Hz,
19F NMR (188.143 MHz, CDCl3, ppm): δ –109.2
CH), 115.3 (d, 2JCP = 22.3 Hz, Caro), 119.2 (td, 1JCF
=
=
=
2
2
1
1
(dd, JFF = 302.5 Hz, JFP = 116.2 Hz), –108.6 (dd,
266.8 Hz, JCP = 153.2 Hz, CF2), 126.3 (d, JCP
2
2JFF = 302.5 Hz, 2JFP = 116.2 Hz). 13C (100.62 MHz,
134.6 Hz, Caro), 128.2 (m, Caro), 128.5 (d, JCF
3
CDCl3, ppm): δ 21.4 (s, CH3-Caro), 23.9 (d, JCP
=
13.2 Hz, Caro), 128.9 (td, 3JCF = 7.4 Hz, JCP = 1.5 Hz,
3
3
4.4 Hz, CH3), 24.4 (d, JCP = 3.4 Hz, CH3), 72.6
Caro), 133.1 (d, JCF = 9.8 Hz, Caro), 133.5 (d, JCP
=
2
1
1
(d, JCP = 6.9 Hz, CH), 119.7 (td, JCF = 266.2 Hz,
2.2 Hz, Caro), 164.1 (d, JCF = 249.1 Hz, Caro). IR
(KBr), cm−1: 1242 (P O). MS m/z (%): 329.2 (50)
[M+]. Anal. Calcd for C16H16F3O2P (328.27): C,
58.54; H, 4.91; P, 9.44. Found: C, 58.49; H, 4.95;
P, 9.38.
1JCP = 154.9 Hz, CF2), 126.5 (td, 3JCF = 6.8 Hz, JCP
=
1
1.5 Hz, Caro), 126.7 (d, JCP = 134.5 Hz, Caro), 128.4
2
(d, JCP = 13.2 Hz, Caro), 128.9 (s, Caro), 129.3 (m,
2
3
Caro), 133.1 (d, JCF = 10 Hz, Caro), 133.3 (d, JCP
=
3 Hz, Caro), 140.7 (m, JCP = 2.3 Hz, Caro). IR (KBr),
cm−1: 1243 (P O). MS m/z (%): 325.0 (100) [M+].
Anal. Calcd for C17H19F2O2P: C, 62.96; H, 5.91; P,
9.55. Found: C, 62.87; H, 5.85; P, 9.51.
[α,α-Difluoro-(4-chloro-benzyl)]-phenyl-
phosphinic Acid Isopropyl Ester (8k). Compound
8k was obtained from 7k (0.76 g, 2.36 mmol) in
CH2Cl2 (3 mL) and MOST (1.23 g, 7.02 mmol). Pale
yellow oil. Yield: 0.58 g (72%). Rf = 0.30 (CH2Cl2).
1H NMR (299.94 MHz, CDCl3, ppm): δ 1.30 (3H, d,
[α,α-Difluoro-(4-methoxy-benzyl)]-phenyl-
3
phosphinic Acid Isopropyl Ester (8h). Compound
8h was obtained from 7h (0.74 g, 2.36 mmol) in
CH2Cl2 (3 mL) and MOST (2.61 g, 4.90 mmol). The
reaction mixture was refluxed for 9 h. Yield: 0.52 g
3JHH = 6.1 Hz, CH3), 1.31 (3H, d, JHH = 5.9 Hz,
CH3), 4.80 (1H, m, CH), 7.34–7.82 (9H, m, Haro). 31
P
2
NMR (80.95 MHz, CH2Cl2, ppm): δ 24.11 (t, JPF
=
105.8 Hz). 19F NMR (188.143 MHz, CH2Cl2, ppm):
(66%). Pale yellow oil. Rf = 0.19 (CH2Cl2). 1H NMR
δ –109.3 (dd, JFF = 300.8 Hz, JFP = 105.8 Hz),
2
2
3
2
2
(299.94 MHz, CDCl3, ppm): δ 1.30 (3H, d, JHH
=
–108.7 (dd, JFF = 300.8 Hz, JFP = 105.8 Hz).
6.1 Hz, CH3), 1.31 (3H, d, 3JHH = 6.1 Hz, CH3), 3.82
(3H, s, CH3O), 4.77 (1H, m, CH), 6.88–7.83 (9H,
m, Haro). 31P NMR (80.95 MHz, CH2Cl2, ppm): δ
13C (100.62 MHz, CDCl3, ppm): δ 23.9 (d, JCP
=
3
3
4.4 Hz, CH3), 24.4 (d, JCP = 3.1 Hz, CH3), 72.9 (d,
2JCP = 7 Hz, CH), 119.1 (td, 1JCF = 266.9 Hz, 1JCP
=
2
1
24.6 (t, JPF = 107.4 Hz). 19F NMR (188.143 MHz,
153.9 Hz, CF2), 126.1 (d, JCP = 133.6 Hz, Caro),
CH2Cl2, ppm): δ –107.7 (dd, 2JFF = 299.1 Hz, 2JFP
=
=
128.1 (td, JCF = 6.5 Hz, JCP = 1.5 Hz, Caro), 128.5
3
3
2
2
2
107.4 Hz), –107.1 (dd, JFF = 299.1 Hz, JFP
(s, Caro), 128.5 (d, JCP = 13.2 Hz, Caro), 130.8 (m,
107.4 Hz). 13C (100.62 MHz, CDCl3, ppm): δ 23.9 (d,
Caro), 133.1 (d, JCP = 9.5 Hz, Caro), 133.6 (d, JCP
=
3
3JCP = 4.7 Hz, CH3), 24.4 (d, JCP = 3.7 Hz, CH3),
2.8 Hz, Caro), 136.9 (m, Caro). IR (KBr), cm−1: 1247
(P O). MS m/z (%): 345.2 (35) [M+]. Anal. Calcd for
C16H16СlF2O2P: C, 55.75; H, 4.68; P, 8.99. Found: C,
55.63; H, 4.57; P, 9.05.
3
2
55.3 (s, CH3O-Caro), 72.5 (d, JCP = 6.7 Hz, CH),
1
1
113.3 (s, Caro), 119.6 (td, JCF = 266.3 Hz, JCP
=
=
=
1
155.9 Hz, CF2), 124.3 (m, Caro), 126.7 (d, JCP
3
133.6 Hz, Caro), 128.2 (td, JCF = 7.1 Hz, JCP
2
2.2 Hz, Caro), 128.4 (d, JCP = 13.3 Hz, Caro), 133.1
(d, 3JCP = 9.3 Hz, Caro), 133.3 (d, JCP = 2.9 Hz, Caro),
161.4 (m, Caro). IR (KBr), cm−1: 1246 (P O). MS m/z
(%): 341.2 (100) [M+]. Anal. Calcd for C17H19F2O3P:
C, 60.00; H, 5.63; P, 9.10. Found: C, 59.93; H, 5.72;
P 9.05.
Hydrolysis of Morpholinium Salt of
(Fluoro-diphenyl-methyl)-pentafluorophosphate
(9a)
Compound 9a (0.2 g) was dissolved in distilled wa-
ter (4 mL). The reaction mixture was stirred for
Heteroatom Chemistry DOI 10.1002/hc

264 Zasukha, Guzyr, and Shermolovich
[3] Guzyr, O. I.; Zasukha, S. V.; Vlasenko, Yu. G.;
Chernega, A. N.; Rozhenko, A. B.; Shermolovich, Yu.
G. Eur J Inorg Chem 2013, 4154–4158.
[4] Singh, R. P.; Meshri, D. T.; Shreeve, J. M. Modern
Organofluorine Chemistry Synthetic Aspects in Ad-
vances in Organic Synthesis; Bentham Science: Shar-
jah, UAE, 2006; Vol 2, pp 291–326.
[5] (a) Richards, E. M.; Tebby, J. C. Chem Commun 1969,
494–495; (b) Brophy, J. J.; Freeman, K. L.; Gallagher,
M. J. J Chem Soc (C) 1968, 2760–2765.
[6] (a) Lu, G.; Katoh, A.; Zhang, Z.; Hu, Z.; Lei, P.;
Kimura, M. J Heterocyclic Chem 2010, 47, 932–938;
(b) Agrawal, M. K.; Ghosh, P. K. J Org Chem 2009,
74, 7947–7950.
15 h at room temperature and refluxed for 26 h. The
precipitate was filtered and washed with water. The
water layer was extracted with ethyl acetate (3 ×
20 mL); the extracts dried with Na2SO4, evaporated,
combined with precipitate, and dried in a vac-
uum. The total yield of (hydroxy-diphenyl-methyl)-
phosphonic acid 18: 0.13 g. Yield: 98%. The spectro-
scopic data for compound 18 are already reported
[11].
ACKNOWLEDGMENT
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Kurdyumov Institute for Metal Physics of NAS of
Ukraine, Kyiv, Ukraine, for recording the NMR
spectra.
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Heteroatom Chemistry DOI 10.1002/hc