Reaction of trimethylsilyl hypophosphite with aromatic aldehydes and azomethines

Full text of DOI:10.1134/S1070363207090253

ISSN 1070-3632, Russian Journal of General Chemistry, 2007, Vol. 77, No. 9, pp. 1645 1647.
Pleiades Publishing, Ltd., 2007.
Original Russian Text
A.A. Prishchenko, M.V. Livantsov, O.P. Novikova, L.I. Livantsova, 2007, published in Zhurnal Obshchei Khimii, 2007, Vol. 77,
No. 9, pp. 1574 1576.
LETTERS
TO THE EDITOR
Reaction of Trimethylsilyl Hypophosphite
with Aromatic Aldehydes and Azomethines
A. A. Prishchenko, M. V. Livantsov, O. P. Novikova, and L. I. Livantsova
Lomonosov Moscow State University,
Vorob’evy gory, Moscow, 119992 Russia
e-mail: liv@org.chem.msu.su
Received April 9, 2007
DOI: 10.1134/S1070363207090253
Trimethylsilyl esters of hypophosphorous acid are
extensively used in the synthesis of various functional
derivatives of organophosphorus acids, which attract
interest as perspective ligands and biologically active
compounds. Thus, bis(trimethylsiloxy)phosphine is
capable of readily adding to aromatic aldehydes and
azomethines [1], and trimethylsilyl hypophosphite A
easily reacts with 2 equiv of N,N-diethylvinylsulfon-
amide [2]. In the present work we have studied the
reaction of trimethylsilyl hypophosphite A formed
from ammonium hypophosphite and chlorotrimethyl-
silane with aromatic aldehydes and azomethines in
methylene chloride. It was found that hypophosphite
A is capable of easily adding at the carbonyl group of
various aromatic aldehydes to form either phosphoni-
tes Ia Ic or phosphinates IIa IIc, depending on the
reagent ratio, in quite a high yield (cf. [3]). Phosphoni-
tes I were isolated by additional treatment of the reac-
tion mixture with bis(trimethylsilyl)amine, and phos-
phinates II were recrystallized from aqueous ethanol.
(
(
1) ArCHO;
2) (Me Si) NH
Me SiCl
3
2
3
1
NH H PO
2
Me3SiOP(O)H2
(Me3SiO)2PC H(O)(OSiMe3)Ar,
4
2
NH Cl
4
A
Ia Ic
(
1) ArCHO;
(
2) EtOH, H O
2
1
A
HOP[C H(OH)Ar] ,
2
O
IIa IIc
3
4
3
4
3
4
Ar = 2
(a), 2
5
OMe (b), 2
5
5
Br (c).
The reaction of hypophosphite A with 2 equiv of
aromatic azomethines under the same conditions
provides aryl-substituted bis(aminomethyl)phosphi-
nates III in high yield.
(1) ArCH=NMe;
2) EtOH
(
1
A
HOP[C H(NHMe)Ar] ,
2
O
IIIa, IIIb
The NMR spectra of compounds I III show cha-
racteristic signals of the PC H(OX)Ar fragments,
whose parameters are presented below. According to
1
3
4
3
4
Ar = 2
(a), 2
5
5
OMe (b).
the NMR spectra, compounds II and III are mixtures
1645

1646
PRISHCHENKO et al.
of two stereoisomers. The stereoisomer ratios were
determined by 31P NMR spectroscopy, and the data
for the prevailing isomer are given first. For phos-
phinates IIa and IIb only H and P NMR data are
presented because of the minor content of the second
isomer.
chloride was filtered off, the solvent was distilled off,
and 60 ml of ethanol was added to the residue. The
mixture was heated to boil, ethanol was distilled off,
and the residue was recrystallized from 70% aqueous
ethanol. The white crystals that formed were kept in
a vacuum (1 mm Hg) for 1 h to obtain compound IIa.
Yield 21.7 g (78%), mp 187 C. Major isomer (90%).
1
31
Bis(trimethylsilyl) [phenyl(trimethylsiloxy)-
methyl]phosphonite (Ia). A mixture of 8.3 g of
ammonium hypophosphite, 10.6 g of benzaldehyde,
and 26 g of chlorotrimethylsilane in 50 ml of me-
thylene chloride was heated under reflux with stirring
for 2 h. Ammonium chloride was filtered off, the
solvent was distilled off, and 65 g of bis(trimethyl-
silyl)amine was added to the residue. The mixture was
refluxed until ammonia no longer evolved and then
1
1
2
H NMR spectrum, , ppm: 5.17 d (C H, J 8 Hz),
PH
1
3
7
.3 7.5 m (2C H ). C NMR spectrum, C, ppm:
6 5
1
1
2 2
68.96 d (C , J 106 Hz), 139.06 d (C , J 3 Hz),
PC
PC
3
3
4
5
128.14 d (C , J 5 Hz), 128.00 s (C ), 127.35 s (C ).
P NMR spectrum, , ppm: 39.31 s. Minor isomer.
PC
31
P
1
1
2
H NMR spectrum, , ppm: 4.86 d (C H, J 8 Hz),
PH
31
7
.3 7.5 m (2C H ). P NMR spectrum, P, ppm:
6
5
3
7.05 s. Found, %: C 60.09; H 5.49. C H O P.
14 15 4
distilled to obtain 26.4 g of phosphonite Ia, yield
Calculated, %: C 60.43; H 5.43.
1
6
8%, bp 120 C (1.5 mm Hg). H NMR spectrum, ,
Compounds IIb and IIc were prepared by the same
method.
ppm: 0.10 s, 0.02 s and 0.21 s (3Me Si), 4.28 s
3
1
13
(
C H), 7.3 7.4 m (C H ). C NMR spectrum, C,
6 5
ppm: 0.22 s (Me SiOC), 0.80 d and 1.40 d
3
Bis[hydroxy(4-phenoxyphenyl)methyl]phos-
3
1 1
(
1
1
2Me SiOP, J 3 Hz), 82.72 d (C , J 11 Hz),
3 PC PC
phinic acid (IIb). Yield 72% yield, mp 165 C. Major
2
2
3
3
1
39.60 d (C , J 13 Hz), 127.45 d (C , J 5 Hz),
isomer (86%). H NMR spectrum, , ppm: 5.07 d
PC
PC
4
5
31
1
2
3
3
27.67 s (C ), 126.85 s (C ). P NMR spectrum, P,
(C H, J 8 Hz), 6.90 d (C H, J 8 Hz), 7.35 d
PH HH
4
3
13
ppm: 140.47 s.
(C H, J 8 Hz), 3.74 s (MeO). C NMR spectrum,
HH
1
1
2
C, ppm: 68.50 d (C , J 107 Hz), 130.93 d (C ,
PC
Phosphonites Ib and Ic were synthesized by the
same method.
2J 4 Hz), 129.36 d (C , J 4 Hz), 113.56 s (C ),
3
2
4
PC
PC
5
31
1
58.95 s (C ). P NMR spectrum, P, ppm: 38.88 s.
1
Bis(trimethylsilyl) [(4-methoxyphenyl)(tri-
Minor isomer. H NMR spectrum, H, ppm: 4.75 d
1
2
3
3
methylsiloxy)methyl]phosphonite (Ib). Yield 59%,
(C H, J 8 Hz), 7.14 d (C H, J 8 Hz), 7.89 d
PH HH
1
4
3
31
bp 115 C (1 mm Hg). H NMR spectrum, , ppm:
(C H, J 8 Hz), 3.74 s (MeO). P NMR spectrum,
HH
1
0
.16 s, 0.06 s and 0.14 s (3Me Si), 4.15 s (C H),
P, ppm: 36.96 s. Found, %: C 56.69; H 5.72. C H
3
16 19
3
3
4
3
6
3
.74 d (C H, J 8 Hz), 7.10 d (C H, J 8 Hz),
.64 s (MeO). 1 C NMR spectrum, , ppm: 0.18 s,
.77 s and 1.32 s (3Me Si), 82.18 d (C , J 9 Hz),
31.72 d (C , J 13 Hz), 128.51 d (C , J 5 Hz),
O P. Calculated, %: C 56.81; H 5.66.
HH
HH
6
3
C
Bis[(4-bromophenyl)hydroxymethyl)]phosphinic
acid (IIc). Yield 52%, mp 162 C. Major isomer
1
1
0
1
1
3 PC
2
2
3 3
1
1
2
PC
PC
31
(55%). H NMR spectrum, , ppm: 4.87 d (C H, J
PH
4
5
1
3
13.13 s (C ), 158.77 s (C ), 54.89 s (MeO). P NMR
8
Hz), 7.2 7.6 m (2C H ). C NMR spectrum, C,
6 5
ppm: 69.64 d (C , J 104 Hz), 138.70 s (C ),
30.14 s (C ), 130.97 s (C ), 120.74 s (C ). P NMR
spectrum, , ppm: 35.95 s. Minor isomer. H NMR
spectrum, P, ppm: 140.07 s.
1
1
2
PC
3
4
5
31
1
Bis(trimethylsilyl) [(4-bromophenyl)(trimethyl-
1
siloxy)methyl]phosphonite (Ic). Yield 64%, bp
P
1
2
1
spectrum, , ppm: 5.15 d (C H, J 8 Hz), 7.2 7.6 m
1
59 C (1 mm Hg), mp 62 C. H NMR spectrum, H,
PH
13
1
(
2C H ). C NMR spectrum, , ppm: 68.46 d (C ,
ppm: 0.12 s, 0.04 s and 0.12 s (3Me Si), 4.19 s
6 5 C
3
1
3
3
4
3
1
2
3
(
8
(
C H), 7.06 d (C H, J 8 Hz), 7.32 d (C H, J
J
106 Hz), 138.33 s (C ), 130.14 s (C ), 130.97 s
(C ), 120.77 s (C ). P NMR spectrum, P, ppm:
38.10 s.
HH
HH
PC
1
3
4
5
31
Hz).
C NMR spectrum,
, ppm: 0.16 s
C
3
Me SiOC), 0.90 d and 1.35 d(2 Me SiOP, J 3 Hz),
3
3
PC
1
1
2 2
8
1
1.77 d (C , J 14 Hz), 138.60 d (C , J 11 Hz),
PC PC
3
3
4
5
Bis[(methylamino)phenylmethyl]phosphinic
acid (IIIa). A mixture of 8.3 g of ammonium hypo-
phosphite, 25.2 g of benzylidene(methyl)amine, and
17 g of chlorotrimethylsilane in 60 ml of methylene
chloride heated under reflux with stirring for 2 h.
Ammonium chloride was filtered off, the solvent was
removed in a vacuum, and 60 ml of ethanol was
added to the residue. The mixture was heated to boil;
28.89 d (C , J 4 Hz), 130.60 s (C ), 120.50 s (C ).
PC
3
1
P NMR spectrum, P, ppm: 139.22.
Bis[hydroxy(phenyl)methyl]phosphinic acid
IIa). A mixture of 8.3 g of ammonium hypophos-
(
phite, 22.4 g of benzaldehyde, and 40 g of chlorotri-
methylsilane in 60 ml of methylene chloride was
heated under reflux with stirring for 2 h. Ammonium
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 9 2007

REACTION OF TRIMETHYLSILYL HYPOPHOSPHITE
1647
1
1
2
3
the precipitate that formed was filtered off and washed
with 20 ml of ethanol and 20 ml of ether. The result-
ing white fine crystals were kept in a vacuum of
(C , J
96 Hz), 132.28 s (C ), 131.52 s (C ),
PC
4
5
114.21 s (C ), 160.78 s (C ), 31.66 s (MeN), 54.82 s
MeO). 31P NMR spectrum, P, ppm: 21.52 s. Found,
: C 59.12; H 6.97. C H N O P. Calculated, %:
18 25 2 4
C 59.33; H 6.92.
(
%
1
mm Hg for 1 h to obtain compound IIIa. Yield 28 g
1
(
92%), mp 214 C. Major isomer (67%). H NMR
1
2
spectrum, , ppm: 4.69 d (C H, J 8 Hz), 2.55 s
PH
1
3
(
MeN), 7.2 7.5 m (2 C H ). C NMR spectrum, C,
6 5
The NMR spectra were recorded on a Bruker
Avance 400 spectrometer in CDCl (phosphonites I),
(CD ) SO (phosphinates II), and CD COOD (phos-
phinates III) against TMS ( H, C) or 85% H PO in
1
1
ppm: 61.58 d (C , J 95 Hz), 31.89 s (MeN), 128.0
PC
3
3
1
1
1
4
33.0 m (2C H ). P NMR spectrum, P, ppm:
6
5
3 2
3
1
1
13
9.94 s. Minor isomer. H NMR spectrum, , ppm:
3 4
1
2
31
.64 d (C H, J 8 Hz), 2.55 s (MeN), 7.2 7.5 m
D O ( P).
2
PH
1
3
1
(
C H ). C NMR spectrum, , ppm: 61.32 d (C ,
J
6
5
C
1
94 Hz), 31.95 s (MeN), 128.0 133.0 m (2C H ).
PC
6 5
ACKNOWLEDGMENTS
3
1
P NMR spectrum, P, ppm: 19.66 s. Found, %: C
2.97; H 7.09. C H N O P. Calculated, %: C 63.15;
6
1
6
21
2
2
The work was financially supported by the Russian
Foundation for Basic Research (project no. 05-03-
32864).
H 6.96.
Compound IIIb was prepared by the same proce-
dure.
REFERENCES
Bis[(4-methoxyphenyl)(methylamino)methyl]-
phosphinic acid (IIIb). Yield 90%, mp 208 C. Major
isomer (80%). H NMR spectrum, , ppm: 4.54 d
1
2
. Prishchenko, A.A., Livantsov, M.V., Boganova, N.V.,
and Lutsenko, I.F., Zh. Obshch. Khim., 1989, vol. 59,
no. 8, p. 1890; Prishchenko, A.A., Livantsov, M.V.,
Livantsova, L.I., and Kashulin, I.A., Zh. Obshch. Khim.,
1
1
2
3
3
(
(
C H, J 8 Hz), 6.81 d (C H, J 8 Hz), 7.24 d
PH HH
4
3
13
C H, J 8 Hz), 2.56 s (MeN), 3.79 s (MeO).
C
HH
1
1
NMR spectrum, , ppm: 60.95 d (C , J 97 Hz),
C
PC
2
005, vol. 75, no. 10, p. 1748.
2
3
4
1
(
32.28 s (C ), 131.57 s (C ), 114.21 s (C ), 160.49 s
5
31
. Prishchenko, A.A., Livantsov, M.V., Livantsova, L.I.,
Pol’shchikov, D.G., and Grigor’ev, E.V., Zh. Obshch.
Khim., 1997, vol. 67, no. 10, p. 1744.
C ), 31.60 s (MeN), 54.73 s (MeO). P NMR spec-
1
trum, , ppm: 21.00 s. Minor isomer. H NMR spec-
trum, , ppm: 4.39 d (C H, J 8 Hz), 6.96 d (C H,
P
1
2
3
PH
3
4
3
JHH 8 Hz), 7.34 d (C H, J 8 Hz), 2.55 s (MeN),
3. Yamagishi, T., Yokomatsu, T., Suemune, K., and Shi-
HH
3
.83 s (MeO). 13C NMR spectrum, C, ppm: 60.55 d
buya, S., Tetrahedron, 1999, vol. 55, p. 12125.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 9 2007