REACTIONS OF TRIMETHYLSILYL ESTERS OF TRIVALENT PHOSPHORUS ACIDS
1475
In the reactions of diphosphonate II and of diphos-
phinates III and IV with excess methanol, we ob-
tained hydroxymethylenediphosphonic (or -diphos-
phinic) acids V VII as white hygroscopic crystals.
136.38 s (C4), 153.52 s (C5). 31P NMR spectrum,
,
ppm: 16.60 s. Found, %: C 53.59; H 8.57. C26H50O8P
P2Si. Calculated, %: C 53.78; H 8.68.
Compounds II IV were prepared similarly.
Bu-t
Tetrakis(trimethylsilyl) (3,5-di-tert-butyl-4-hy-
droxyphenyl)trimethylsilyloxymethylenediphos-
phonate II. Yield 90%, mp 146 C. H NMR spec-
5MeOH
1
OH
Bu-t
Bu-t
OH
[(HO)2P]2C
O OH
II
5Me3SiOMe
trum, , ppm: 0.04 s and 0.06 s (Me3SiOP), 0.26 s
(Me3SiOC), 1.37 s (Me3C), 5.05 br.s (OH), 7.55 s
(C6H2). 13C NMR spectrum, C, ppm: 0.96 s (Me3
SiOP), 2.99 s (Me3SiOC), 30.27 s (Me3C), 34.44 s
V
1
HO
Y
(Me3C), 79.82 t (C1, JPC 161 Hz), 124.05 s (C3),
3MeOH
C
P
III, IV
127.67 s (C2), 134.46 s (C4), 153.10 s (C5). 31P NMR
spectrum, P, ppm: 0.90 s.
3Me3SiOMe
OH
O
Bu-t
2
Bis(trimethylsilyl) (3,5-di-tert-butyl-4-hydroxy-
VI, VII
phenyl)trimethylsilyloxymethylenebis(2-phenyl-
1
O
ethylphosphinate) III. Yield 92%, mp 111 C. H
NMR spectrum, , ppm: 0.17 s (Me3SiOP), 0.34 s
(Me3SiOC), 1.45 s (Me3C), 5.35 br.s (OH), 7.0 7.5 m
(C6H2, 2C6H5). 13C NMR spectrum, C, ppm: 1.34 s
(Me3SiOP), 3.50 s (Me3SiOC), 30.47 s (Me3C), 34.67
N
(VII).
Y = CH2CH2Ph (VI), CH2CH2
Acids V VII decompose on heating above 120
130 C and do not have clear melting points. The
NMR spectra of I VII contain characteristic signals
of methylenediphosphonic (-diphosphinic) fragments
PC1P, and also signals of substituted aromatic frag-
ments and pyrrolidone moiety. The methylene proton
signals of III, IV, VI, and VII are partially overlap-
ping multiplets.
1
s (Me3C), 83.07 t (C1, JPC 97 Hz), 124.11 s (C3),
126.08 s (C2), 135.42 s (C4), 153.71 s (C5), 28.74 d
1
3
(C6, JPC 97 Hz), 28.16 s (C7), 141.41 d (C8, JPC
8 Hz) and 141.49 d (C8, JPC 8 Hz). 31P NMR spec-
3
trum, , ppm: 39.16 s.
Bis(trimethylsilyl) (3,5-di-tert-butyl-4-hydroxy-
phenyl)trimethylsilyloxymethylenebis[2-(2-oxopyr-
rolidino)ethylphosphinate] IV. Yield 93%, mp
Tetraethyl (3,5-di-tert-butyl-4-hydroxyphenyl)-
trimethylsilyloxymethylenediphosphonate I. A mix-
ture of 3.8 g of 3,5-di-tert-butyl-4-hydroxybenzoic
acid, 10 ml of hexane, and 8 ml of thionyl chloride
was refluxed for 0.5 h, the solvent was distilled off in
a vacuum, and the residue was kept in a vacuum
(0.5 mm Hg) for 0.5 h. To a solution of thus obtained
acid chloride A in 15 ml of methylene chloride, a
solution of 8 g of diethyl trimethylsilyl phosphite in
20 ml of methylene chloride was added with stirring
and cooling to 10 C. The mixture was stirred for
0.5 h and heated to reflux, after which the solvent was
distilled off, 25 ml of hexane was added to the res-
idue, and the mixture was cooled to 0 C. The precipi-
tated white crystals were filtered off and kept in a
vacuum (0.5 mm Hg) for 1 h. Phosphonate I was
1
129 C. H NMR spectrum, , ppm: 0.07 s (Me3
SiOP), 0.11 s (Me3SiOC), 1.20 s (Me3C), 5.35 br.s
(OH), 7.45 br.s (C6H2). 13C NMR spectrum, C, ppm:
1.08 s (Me3SiOP), 3.19 s (Me3SiOC), 30.18 s (Me3C),
1
36.29 s (Me3C), 82.76 t (C1, JPC 100 Hz), 123.97 t
3
(C3, JPC 5 Hz), 127.87 s (C2), 135.68 s (C4), 153.64 s
1
(C5), 26.04 d (C9, JPC 91 Hz), 34.50 s (C10), 46.48 s
(C11), 17.55 s (C12), 30.56 s (C13), 174.20 s (C14).
31P NMR spectrum, P, ppm: 36.90 s.
(3,5-Di-tert-butyl-4-hydroxyphenyl)hydroxy-
methylenediphosphonic acid V. Diphosphonate II
(8.4 g) was added with stirring and cooling (10 C) to
30 ml of methanol. The mixture was heated to reflux,
the solvent was distilled off, and the residue was kept
in a vacuum (1 mm Hg) for 1 h. Acid V was obtained;
1
obtained; yield 8 g (91%), mp 127 C. H NMR spec-
trum, , ppm: 0.21 s (Me3Si), 1.09 t and 1.24 t
1
yield 4.3 g (98%). H NMR spectrum, , ppm: 1.36 s
(Me3C), 7.62 s (C6H2). 13C NMR spectrum, C, ppm:
3
(CH3CH2O, JHH 6 Hz), 1.40 s (Me3C), 3.8 4.3 m
1
(CH2O), 5.80 br.s (OH), 7.63 s (C6H2). 13C NMR
spectrum, C, ppm: 3.15 s (Me3Si), 15.83 m and
16.04 m (CH3CH2O), 30.35 s (Me3C), 34.43 s
30.95 s (Me3C), 35.08 s (Me3C), 75.73 t (C1, JPC
146 Hz), 123.98 s (C3), 127.99 s (C2), 137.53 s (C4),
152.92 s (C5). 31P NMR spectrum, P, ppm: 16.51 s.
Found, %: C 45.28; H 6.68. C15H26O8P2. Calculated,
%: C 45.46; H 6.61.
(Me3C), 63.60 64.50 m (CH2O), 80.57 t (C1, JPC
1
152 Hz), 123.05 t (C3, JPC 7 Hz), 126.75 s (C2),
3
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 77 No. 8 2007