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8504188 Recombinant DNA molecules
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Synthetic Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/lsyc20
Rearrangement of a Di-t-butyl Aryl Phosphate to a Dit-butyl (2-Hydroxyaryl) phosphonate. A Convenient Preparation of (2-Hydroxyphenyl)-and (2-Hydroxy 5Methoxy Phenyl) Phosphonic Acids a
Balram Dhawan & Derek Redmore
a
a
Petrolite Corporation , St. Louis, MO, 63119 Published online: 05 Dec 2006.
To cite this article: Balram Dhawan & Derek Redmore (1985) Rearrangement of a Di-t-butyl Aryl Phosphate to a Di-t-butyl (2-Hydroxyaryl) phosphonate. A Convenient Preparation of (2-Hydroxyphenyl)-and (2-Hydroxy 5-Methoxy Phenyl) Phosphonic Acids, Synthetic Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry, 15:5, 411-416 To link to this article: http://dx.doi.org/10.1080/00397918508063819
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
SYNTHETIC COMMUNICATIONS, 1 5 ( 5 ) , 411-416
(1985)
REARRANGEMENT OF A Di-t-BUTYL A R Y L PHOSPHATE TO A Di-t-BUTYL (2-HYDROXYARYL) PHOSPHONATE. A CONVENIENT PREPARATION OF
Downloaded by [University of Sydney] at 07:05 03 September 2014
(2-HYDR0XYPHENYL)-AND
(2-HYDROXY 5-WETHOXY PHENYL) PHOSPHONIC ACIDS
Balram Dhawan * a n d Derek R e d m o r e P e t r o l i t e Corporation, St. Louis, MO. 63119 (2-Hydroxyphenyl) phosphonic a c i d ta phosphorus analogue of salicylic a c i d is to d a t e a difficultly accessible compound.
The two reported
preparations of 4a s t a r t with difficultly available s t a r t i n g m a t e r i a l s a n d give
z
poor overall yields.
Whereas F r e e d m a n 1 o b t a i n e d 4a in 16% overall yield
s t a r t i n g with (2-nitro phenyl) benzyl e t h e r a n d r e p o r t e d a melting point of 124127oC, Lukin and Kalanina2 c l a i m e d to h a v e obtained 4a in 410’0 yield by t h e
z
t r e a t m e n t of (2-brornophenyl) phosphonic acid with aq. a m m o n i a in p r e s e n c e of c u p r o u s oxide? a n d r e p o r t e d a melting point of 178-179OC.
In addition to t h e
d i f f e r e n c e in melting point, t h e products obtained by t h e above t w o m e t h o d s s e e m e d to d i f f e r in their solubility in w a t e r .
In a r e c e n t a r t i c l e 4 o n t h e r e a r r a n g e m e n t of diethyl a r y l phosphates t o d i e t h y l (2-hydroxyaryl)
phosphonates, w e r e p o r t e d t h e preparation of t h e
anilinium s a l t of 4a. Hydrolysis of diethyl (2-hydroxyphenyl) phosphonate 3a to 2,
2,
4a w a s a c h i e v e d via t r a n s e s t e r i f i c a t i o n with trirnethylsilyl chloridelsodium z iodide followed by t r e a t m e n t with water. Because of difficulty in purification
*
To whom correspondence should b e addressed.
411 Copyright 0 1985 by Marcel Dekker, Inc.
0039-7911/85/15054411%3.50/0
DHAWAN AND REDMORE
4 12
4a was isolated a s a monoanilinium salt.
We now r e p o r t t h a t use of t-butyl
’L
groups i n s t e a d of e t h y l groups o f f e r s c e r t a i n a d v a n t a g e s and p e r m i t s t h e preparation of (2-hydroxy phenyl) phosphonic acid a s a w h i t e c r y s t a l l i n e solid in
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an overall yield of 58% f r o m readily a v a i l a b l e s t a r t i n g m a t e r i a l , phenol.
4
3 z
2
1
z
’L
a
R l = H ; R=C2Hg
b
R i z O C H 3 ; R=CzHtj
c
R1=H;
d
R 1 =OC H 3; R=t-butyl
z
R=t-butyl
T r e a t m e n t of sodium phenoxide l a with di-t-butyl p h o s p h o r o c h l o r i d a t e ~in z
T H F g a v e di-t-butyl phenyl phosphate 2 c which on t r e a t m e n t w i t h lithium 7r
diisopropylarnide in T H F underwent c l e a n r e a r r a n g e m e n t to di-t-butyl
(2-
hydroxyphenyl) phosphonate 3c. T r e a t m e n t of 3c with t r i f l u o r o a c e t i c a c i d in a n z
a p r o t i c solvent b e n z e n e (thus avoiding use of w a t e r t h a t m a k e s isolation of 4 a z
difficult) resulted in loss of t-butyl groups a n d (2-hydroxyphenyl) phosphonic a c i d 4a fell o u t of t h e solution as a solid. ?r
(2-Hydroxy-5-methoxy
phenyl) phosphonic acid 4b w a s o b t a i n e d f r o m I b ’L
by a similar r e a c t i o n s e q u e n c e in a n overall yield of 58%. Both
4,” a n d
4,b w e r e
c h a r a c t e r i z e d by lH, 13C, 31P s p e c t r a , e l e m e n t a l a n a l y s i s a n d p o t e n t i o m e t r i c titration.
413
PHOSPHONIC ACIDS
EXPERIMENTAL Melting points w e r e obtained on a Melt t e m p melting point a p p a r a t u s a n d a r e uncorrected.
The e l e m e n t a l analyses w e r e p e r f o r m e d by G a l b r a i t h
Laboratories, Knoxville, T N a n d P e t r o l i t e Corporation, Analytical Section. l H NMR S p e c t r a w e r e obtained with a Perkin-Elmer R-32 s p e c t r o m e t e r (90 \!!-Iz)
Downloaded by [University of Sydney] at 07:05 03 September 2014
using MeqSi for CDCI3 solutions and t h e sodium s a l t of 3-(trimethylsilyl! propionic a c i d f o r D 2 0 solutions as i n t e r n a l standards.
31P a n d 13C s p e c t r a
w e r e obtained with a J e o l FX-60 s p e c t r o m e t e r o p e r a t i n g at 24.15 a n d 15.04 MH,, respectively. The c h e m i c a l s h i f t (+ ) values a r e downfield from H 3 P 0 4 (cap) for 31P s p e c t r a a n d f r o m Me4Si for 13C s p e c t r a .
Di-t-butyl phenyl phosphate 2c. T o a s t i r r e d solution of phenol (3.29g, 3 5 %
mmol) in 4 5 mL T H F w a s added sodium hydride (0.84g).
The reaction mixture
w a s cooled in i c e b a t h and di-t-butyl phosphorochloridate (Log, 3 5 mmol) w a s added dropwise.
The r e a c t i o n m i x t u r e was n e x t r e f r i g e r a t e d f o r 7 2 h and then
s t i r r e d a t room t e m p e r a t u r e f o r
3 h.
The solvent w a s n e x t removed on a r o t a r y
evaporator. Water (30 mL) and m e t h y l e n e chloride (100 mL) w e r e added t o t h e residue. T h e o r g a n i c layer w a s s e p a r a t e d , dried over Na2SOu and then solvent was r e m o v e d o n a r o t a r y e v a p o r a t o r t o yield di-t-butyl phenyl phosphate as a n oil 8.9g (89%). I t w a s used without f u r t h e r purification in t h e n e x t step. l H N M R (CDC13) 1.52 (s, 18H, CH3), 7.25 (Apparent s, 5H, Ar). 1 3 C NMR (CDC13) 29.87 (d, 3.91Hz, CH3), 83.50 (d. 7.81Hz 119.93 (d. 5.86 H,,
(CH3)3),
C2, Cg), 124.15 (C4), 129.34 (C3, Cg), 151.48 (d, 5.86
H,, C1). 3 1 P NMR (CDC13) -15.62.
Di-t-butyl
(2-hydroxyphenyl) phosphonate 3c. %
T o a s t i r r e d solution of
diisopropylamine (6.06g) in T H F (30 mL) under nitrogen a t m o s p h e r e a t -78OC w a s a d d e d n-butyllithium (37.5 m L of 1.6M solution in hexane).
The mixture
DHAWAN AND REDMORE
414
was s t i r r e d a t -78OC for 30 min when a w h i t e slurry w a s formed.
Di-t-butyl
phenyl phosphate (8.58g, 30 mmol) dissolved in 30 mL T H F w a s n e x t added with a syringe.
A f t e r s t i r r i n g a t -78OC for I h dry i c e - a c e t o n e b a t h w a s r e m o v e d
and t h e s t i r r i n g was continued for a n additional 2 h. T h e r e a c t i o n m i x t u r e w a s
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n e x t poured over a m i x t u r e of 100 mL s a t u r a t e d aq. NH4CI a n d 200 mL m e t h y l e n e chloride.
The organic l a y e r w a s s e p a r a t e d , washed with w a t e r and
dried over Na2S04.
Removal of solvent on r o t a r y e v a p o r a t o r g a v e di-t-butyl
(2-hydroxy phenyl) phosphonate as a n oil 8.10g (94.4%).
This w a s used in t h e
n e x t s t e p a s such.
IH N M R (CDC13) 1.48
2H, Ar).
(5,
18H, CH3), 6.75-7.05 (m, 2H, Ar), 7.24-7.54 (m,
C
I3C NMR (CDC13) 30.19 (d, 3.91Hz, CH3), 83.56 (d. 7.81 H,
(CH3)3), 114.44 (d, 156.52 H,, C I ) , 116.13 (d, 20.50 H,, 12.70 H,,
C5), 115.11 (d,
C3), 131.81 (d, 5.86 H,, CG), 133.95 (C41, 160.25 (d, 7.81 H,
c 2 ) . 31p N V R (CDC13) + 13.65.
2-Hydroxyphenyl phosphonic Acid6
4a. z
A m i x t u r e of di-t-butyl (2-
hydroxy phenyl) phosphonate (8.lg), b e n z e n e (40 mL) and t r i f l u o r o a c e t i c a c i d (4.9g) was s t i r r e d a t room t e m p e r a t u r e f o r 24 h.
2-Hydroxyphenyl phosphonic
acid p r e c i p i t a t e d o u t a s a t a n colored solid a n d w a s c o l l e c r e d by fi1,tration. T h e c r u d e product was dissolved in 50 mL d e n a t u r e d alcohol, t r e a t e d with c h a r c o a l , f i l t e r e d (celite) and e v a p o r a t e d t o a l m o s t dryness on a r o t a r y e v a p o r a t o r . Addition of m e t h y l e n e chloride to t h e residue g a v e a light-yellow colored solution from which 2-hydroxyphenylphosphonic acid c r y s t a l l i z e d out slowly a s a w h i t e solid.
T h e yield of p u r e m a t e r i a l w a s 3.4g (69%): m p 129.5-130°C;
IV
N M R ( D 2 0 ) 6.85-7.22 (m, 2H, Ar), 7.38-7.86 (m, 2H, Ar); 13C NhlR (D20/MeqSi cap.), 117.21 (d, 179.69HZ, C l ) , 117.34 (d, 9.76 Hz, Cg), 121.31 (d, 13.63, C3), 133.65 (d, 7.81 H,, Cg), 135.40 (C4), 159.19 (d, 3.91 H,, Cz), 15.77. P o t e n t i o m e t r i c Mol. wt. 173.44 C a l c d 174.
31P NMR ( D 2 0 ) +
415
PHOSPHONIC ACIDS C , 41.38; H, 4.02; P, 17.82.
Anal. calcd for C6H704P:
C, 41.27; H, 4.14; P, 17.51.
Found:
Di-t-butyl (4-methoxyphenyl) phosphate 2d. Starting with 40 rnmol of 4%
methoxyphenol, the yield was 10.4g (82%).
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1H NMR (CDCI3) 1.50 (s, 18H, CH3), 3.75 (s, 3H, OCH31, 6.83 (d, JH-H = 9Hz, 2H, Ar), 7.15 (d, JH-H = 9 Hz, 2H, Ar).
13C NMR (CDC13) 29.74 (d,
3.91 H,, C(CH3)3), 55.19 (OCH31, 82.92 (d, 7.81 Hz,
2 (CH313) 114.21
(Cg,
C5), 120.74 (d, 4.88 H,, C2, Cg), 114.99 (d, 7.86 Hz, C l ) , 156.16 (C4). 31P NMR (CDCI3) Di-t-butyl 10.2g
of
-
14.94.
(2-hydroxy-5-rnethoxyphenyl)
di-t-butyl
(4-rnethoxyphenyl)
phosphonate 3.,
Starting with
phosphate
and
2,d
lithium
diisopropylamide (prepared from 6.65g of diisopropylarnine and 40.4 rnL of 1.644 n-butyllithium solution in hexane), t h e yield was 9.9g !97?6).
IH NMR (CDC13) 1.50 (s, 18H, CH3), 3.78 3H, Ar).
3H, OCH3), 6.70-7.00
(5,
(m,
13C NMR (CDC13) 30.26 (d, 3.91 Hz, C(CH3)3J, 55.70 (OCH?),
83.69 (d, 5.86 Hz,L(CH3)3), 114.34 (d, 185.55 Hz, Cl), 114.99 (d, 5 2 6 H7, Cg), 118.24 (d, 13.67 HZ, Cg), 121.29 (Cq), 152.00 (d, 17.58 Hz, C5), 154.40 (d, 7.81 Hz, C2). 31P NMR (CDC13) + 13.14.
(2-Hydroxy-5-Methoxyphenyl)phosphonic acid 4,b. Starting with 9.9g of dit-butyl 2-hydroxy-5-methoxyphenyl
phosphonate and 5.363 of trifluoroacetic
acid, t h e yield was 4.65g (72.6%): rnp 158-159OC. O C H j ) , 6.80-7.32
(m, 3H, Ar).
IH fIMR (n2o), 3.82
(s, 3 4 ,
13C NMR (D20/MeqSi cap.) 57.00 (OCH?)3,
117.33 (d, 179.69 Hz, C l ) , 117.62 (d, 8.79 Hz, C6), 118.37 (d, 13.67 H 7 , Cg), 121.48 (C4), 152.84 (d, 17.58 Hz, C5), 153.27 (d, 4.88 Hz, C2). 31P NMR (n20)
+ 14.86. P o t e n t i o m e t r i c Mol. W t . 203.54. Calcd 204.
4 16
DHAWAN AM) REDMORE
Anal. C a l c d f o r C7Hq05P:
C, 41.18;
Found:
H, 4.42; P, 15.20.
C, 41.18; H, 4.59;
P, 15.24.
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REFERENCES 1.
F r e e d m a n , L. D.; Doak, G. 0.; P e t i t e , E. L.; 3. Org. C h e m . 1960,2, 140.
2.
Lukin A. XI.; a n d Kalanina, 1.
3.
Doak and F r e e d m a n (J. Am. C h e m . SOC. 195?,
n.;
Zh. Obshch. Khim. 1960,2, 1597.
3, 753) O b t a i n e d
'2-
aminophenyl) phosphonic acid under conditions s i m i l a r to t h a t used by Lukin and Kalanina (Ref. 2). R e d m o r e , D.; J. Org. chern. 1984, E, 4018.
4.
Dhawan, B.;
5.
Gajda, T.; Zwierzak, A.; Synthesis, 1976, 243.
6.
Our product posseses p r o p e r t i e s in a g r e e m e n t with Freedman's p r o d u c t (Ref. 1) b u t n o t with t h e p r o d u c t o b t a i n e d by Lukin a n d Kalanina (Ref. 21.
Synthetic Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/lsyc20
Rearrangement of a Di-t-butyl Aryl Phosphate to a Dit-butyl (2-Hydroxyaryl) phosphonate. A Convenient Preparation of (2-Hydroxyphenyl)-and (2-Hydroxy 5Methoxy Phenyl) Phosphonic Acids a
Balram Dhawan & Derek Redmore
a
a
Petrolite Corporation , St. Louis, MO, 63119 Published online: 05 Dec 2006.
To cite this article: Balram Dhawan & Derek Redmore (1985) Rearrangement of a Di-t-butyl Aryl Phosphate to a Di-t-butyl (2-Hydroxyaryl) phosphonate. A Convenient Preparation of (2-Hydroxyphenyl)-and (2-Hydroxy 5-Methoxy Phenyl) Phosphonic Acids, Synthetic Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry, 15:5, 411-416 To link to this article: http://dx.doi.org/10.1080/00397918508063819
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
SYNTHETIC COMMUNICATIONS, 1 5 ( 5 ) , 411-416
(1985)
REARRANGEMENT OF A Di-t-BUTYL A R Y L PHOSPHATE TO A Di-t-BUTYL (2-HYDROXYARYL) PHOSPHONATE. A CONVENIENT PREPARATION OF
Downloaded by [University of Sydney] at 07:05 03 September 2014
(2-HYDR0XYPHENYL)-AND
(2-HYDROXY 5-WETHOXY PHENYL) PHOSPHONIC ACIDS
Balram Dhawan * a n d Derek R e d m o r e P e t r o l i t e Corporation, St. Louis, MO. 63119 (2-Hydroxyphenyl) phosphonic a c i d ta phosphorus analogue of salicylic a c i d is to d a t e a difficultly accessible compound.
The two reported
preparations of 4a s t a r t with difficultly available s t a r t i n g m a t e r i a l s a n d give
z
poor overall yields.
Whereas F r e e d m a n 1 o b t a i n e d 4a in 16% overall yield
s t a r t i n g with (2-nitro phenyl) benzyl e t h e r a n d r e p o r t e d a melting point of 124127oC, Lukin and Kalanina2 c l a i m e d to h a v e obtained 4a in 410’0 yield by t h e
z
t r e a t m e n t of (2-brornophenyl) phosphonic acid with aq. a m m o n i a in p r e s e n c e of c u p r o u s oxide? a n d r e p o r t e d a melting point of 178-179OC.
In addition to t h e
d i f f e r e n c e in melting point, t h e products obtained by t h e above t w o m e t h o d s s e e m e d to d i f f e r in their solubility in w a t e r .
In a r e c e n t a r t i c l e 4 o n t h e r e a r r a n g e m e n t of diethyl a r y l phosphates t o d i e t h y l (2-hydroxyaryl)
phosphonates, w e r e p o r t e d t h e preparation of t h e
anilinium s a l t of 4a. Hydrolysis of diethyl (2-hydroxyphenyl) phosphonate 3a to 2,
2,
4a w a s a c h i e v e d via t r a n s e s t e r i f i c a t i o n with trirnethylsilyl chloridelsodium z iodide followed by t r e a t m e n t with water. Because of difficulty in purification
*
To whom correspondence should b e addressed.
411 Copyright 0 1985 by Marcel Dekker, Inc.
0039-7911/85/15054411%3.50/0
DHAWAN AND REDMORE
4 12
4a was isolated a s a monoanilinium salt.
We now r e p o r t t h a t use of t-butyl
’L
groups i n s t e a d of e t h y l groups o f f e r s c e r t a i n a d v a n t a g e s and p e r m i t s t h e preparation of (2-hydroxy phenyl) phosphonic acid a s a w h i t e c r y s t a l l i n e solid in
Downloaded by [University of Sydney] at 07:05 03 September 2014
an overall yield of 58% f r o m readily a v a i l a b l e s t a r t i n g m a t e r i a l , phenol.
4
3 z
2
1
z
’L
a
R l = H ; R=C2Hg
b
R i z O C H 3 ; R=CzHtj
c
R1=H;
d
R 1 =OC H 3; R=t-butyl
z
R=t-butyl
T r e a t m e n t of sodium phenoxide l a with di-t-butyl p h o s p h o r o c h l o r i d a t e ~in z
T H F g a v e di-t-butyl phenyl phosphate 2 c which on t r e a t m e n t w i t h lithium 7r
diisopropylarnide in T H F underwent c l e a n r e a r r a n g e m e n t to di-t-butyl
(2-
hydroxyphenyl) phosphonate 3c. T r e a t m e n t of 3c with t r i f l u o r o a c e t i c a c i d in a n z
a p r o t i c solvent b e n z e n e (thus avoiding use of w a t e r t h a t m a k e s isolation of 4 a z
difficult) resulted in loss of t-butyl groups a n d (2-hydroxyphenyl) phosphonic a c i d 4a fell o u t of t h e solution as a solid. ?r
(2-Hydroxy-5-methoxy
phenyl) phosphonic acid 4b w a s o b t a i n e d f r o m I b ’L
by a similar r e a c t i o n s e q u e n c e in a n overall yield of 58%. Both
4,” a n d
4,b w e r e
c h a r a c t e r i z e d by lH, 13C, 31P s p e c t r a , e l e m e n t a l a n a l y s i s a n d p o t e n t i o m e t r i c titration.
413
PHOSPHONIC ACIDS
EXPERIMENTAL Melting points w e r e obtained on a Melt t e m p melting point a p p a r a t u s a n d a r e uncorrected.
The e l e m e n t a l analyses w e r e p e r f o r m e d by G a l b r a i t h
Laboratories, Knoxville, T N a n d P e t r o l i t e Corporation, Analytical Section. l H NMR S p e c t r a w e r e obtained with a Perkin-Elmer R-32 s p e c t r o m e t e r (90 \!!-Iz)
Downloaded by [University of Sydney] at 07:05 03 September 2014
using MeqSi for CDCI3 solutions and t h e sodium s a l t of 3-(trimethylsilyl! propionic a c i d f o r D 2 0 solutions as i n t e r n a l standards.
31P a n d 13C s p e c t r a
w e r e obtained with a J e o l FX-60 s p e c t r o m e t e r o p e r a t i n g at 24.15 a n d 15.04 MH,, respectively. The c h e m i c a l s h i f t (+ ) values a r e downfield from H 3 P 0 4 (cap) for 31P s p e c t r a a n d f r o m Me4Si for 13C s p e c t r a .
Di-t-butyl phenyl phosphate 2c. T o a s t i r r e d solution of phenol (3.29g, 3 5 %
mmol) in 4 5 mL T H F w a s added sodium hydride (0.84g).
The reaction mixture
w a s cooled in i c e b a t h and di-t-butyl phosphorochloridate (Log, 3 5 mmol) w a s added dropwise.
The r e a c t i o n m i x t u r e was n e x t r e f r i g e r a t e d f o r 7 2 h and then
s t i r r e d a t room t e m p e r a t u r e f o r
3 h.
The solvent w a s n e x t removed on a r o t a r y
evaporator. Water (30 mL) and m e t h y l e n e chloride (100 mL) w e r e added t o t h e residue. T h e o r g a n i c layer w a s s e p a r a t e d , dried over Na2SOu and then solvent was r e m o v e d o n a r o t a r y e v a p o r a t o r t o yield di-t-butyl phenyl phosphate as a n oil 8.9g (89%). I t w a s used without f u r t h e r purification in t h e n e x t step. l H N M R (CDC13) 1.52 (s, 18H, CH3), 7.25 (Apparent s, 5H, Ar). 1 3 C NMR (CDC13) 29.87 (d, 3.91Hz, CH3), 83.50 (d. 7.81Hz 119.93 (d. 5.86 H,,
(CH3)3),
C2, Cg), 124.15 (C4), 129.34 (C3, Cg), 151.48 (d, 5.86
H,, C1). 3 1 P NMR (CDC13) -15.62.
Di-t-butyl
(2-hydroxyphenyl) phosphonate 3c. %
T o a s t i r r e d solution of
diisopropylamine (6.06g) in T H F (30 mL) under nitrogen a t m o s p h e r e a t -78OC w a s a d d e d n-butyllithium (37.5 m L of 1.6M solution in hexane).
The mixture
DHAWAN AND REDMORE
414
was s t i r r e d a t -78OC for 30 min when a w h i t e slurry w a s formed.
Di-t-butyl
phenyl phosphate (8.58g, 30 mmol) dissolved in 30 mL T H F w a s n e x t added with a syringe.
A f t e r s t i r r i n g a t -78OC for I h dry i c e - a c e t o n e b a t h w a s r e m o v e d
and t h e s t i r r i n g was continued for a n additional 2 h. T h e r e a c t i o n m i x t u r e w a s
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n e x t poured over a m i x t u r e of 100 mL s a t u r a t e d aq. NH4CI a n d 200 mL m e t h y l e n e chloride.
The organic l a y e r w a s s e p a r a t e d , washed with w a t e r and
dried over Na2S04.
Removal of solvent on r o t a r y e v a p o r a t o r g a v e di-t-butyl
(2-hydroxy phenyl) phosphonate as a n oil 8.10g (94.4%).
This w a s used in t h e
n e x t s t e p a s such.
IH N M R (CDC13) 1.48
2H, Ar).
(5,
18H, CH3), 6.75-7.05 (m, 2H, Ar), 7.24-7.54 (m,
C
I3C NMR (CDC13) 30.19 (d, 3.91Hz, CH3), 83.56 (d. 7.81 H,
(CH3)3), 114.44 (d, 156.52 H,, C I ) , 116.13 (d, 20.50 H,, 12.70 H,,
C5), 115.11 (d,
C3), 131.81 (d, 5.86 H,, CG), 133.95 (C41, 160.25 (d, 7.81 H,
c 2 ) . 31p N V R (CDC13) + 13.65.
2-Hydroxyphenyl phosphonic Acid6
4a. z
A m i x t u r e of di-t-butyl (2-
hydroxy phenyl) phosphonate (8.lg), b e n z e n e (40 mL) and t r i f l u o r o a c e t i c a c i d (4.9g) was s t i r r e d a t room t e m p e r a t u r e f o r 24 h.
2-Hydroxyphenyl phosphonic
acid p r e c i p i t a t e d o u t a s a t a n colored solid a n d w a s c o l l e c r e d by fi1,tration. T h e c r u d e product was dissolved in 50 mL d e n a t u r e d alcohol, t r e a t e d with c h a r c o a l , f i l t e r e d (celite) and e v a p o r a t e d t o a l m o s t dryness on a r o t a r y e v a p o r a t o r . Addition of m e t h y l e n e chloride to t h e residue g a v e a light-yellow colored solution from which 2-hydroxyphenylphosphonic acid c r y s t a l l i z e d out slowly a s a w h i t e solid.
T h e yield of p u r e m a t e r i a l w a s 3.4g (69%): m p 129.5-130°C;
IV
N M R ( D 2 0 ) 6.85-7.22 (m, 2H, Ar), 7.38-7.86 (m, 2H, Ar); 13C NhlR (D20/MeqSi cap.), 117.21 (d, 179.69HZ, C l ) , 117.34 (d, 9.76 Hz, Cg), 121.31 (d, 13.63, C3), 133.65 (d, 7.81 H,, Cg), 135.40 (C4), 159.19 (d, 3.91 H,, Cz), 15.77. P o t e n t i o m e t r i c Mol. wt. 173.44 C a l c d 174.
31P NMR ( D 2 0 ) +
415
PHOSPHONIC ACIDS C , 41.38; H, 4.02; P, 17.82.
Anal. calcd for C6H704P:
C, 41.27; H, 4.14; P, 17.51.
Found:
Di-t-butyl (4-methoxyphenyl) phosphate 2d. Starting with 40 rnmol of 4%
methoxyphenol, the yield was 10.4g (82%).
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1H NMR (CDCI3) 1.50 (s, 18H, CH3), 3.75 (s, 3H, OCH31, 6.83 (d, JH-H = 9Hz, 2H, Ar), 7.15 (d, JH-H = 9 Hz, 2H, Ar).
13C NMR (CDC13) 29.74 (d,
3.91 H,, C(CH3)3), 55.19 (OCH31, 82.92 (d, 7.81 Hz,
2 (CH313) 114.21
(Cg,
C5), 120.74 (d, 4.88 H,, C2, Cg), 114.99 (d, 7.86 Hz, C l ) , 156.16 (C4). 31P NMR (CDCI3) Di-t-butyl 10.2g
of
-
14.94.
(2-hydroxy-5-rnethoxyphenyl)
di-t-butyl
(4-rnethoxyphenyl)
phosphonate 3.,
Starting with
phosphate
and
2,d
lithium
diisopropylamide (prepared from 6.65g of diisopropylarnine and 40.4 rnL of 1.644 n-butyllithium solution in hexane), t h e yield was 9.9g !97?6).
IH NMR (CDC13) 1.50 (s, 18H, CH3), 3.78 3H, Ar).
3H, OCH3), 6.70-7.00
(5,
(m,
13C NMR (CDC13) 30.26 (d, 3.91 Hz, C(CH3)3J, 55.70 (OCH?),
83.69 (d, 5.86 Hz,L(CH3)3), 114.34 (d, 185.55 Hz, Cl), 114.99 (d, 5 2 6 H7, Cg), 118.24 (d, 13.67 HZ, Cg), 121.29 (Cq), 152.00 (d, 17.58 Hz, C5), 154.40 (d, 7.81 Hz, C2). 31P NMR (CDC13) + 13.14.
(2-Hydroxy-5-Methoxyphenyl)phosphonic acid 4,b. Starting with 9.9g of dit-butyl 2-hydroxy-5-methoxyphenyl
phosphonate and 5.363 of trifluoroacetic
acid, t h e yield was 4.65g (72.6%): rnp 158-159OC. O C H j ) , 6.80-7.32
(m, 3H, Ar).
IH fIMR (n2o), 3.82
(s, 3 4 ,
13C NMR (D20/MeqSi cap.) 57.00 (OCH?)3,
117.33 (d, 179.69 Hz, C l ) , 117.62 (d, 8.79 Hz, C6), 118.37 (d, 13.67 H 7 , Cg), 121.48 (C4), 152.84 (d, 17.58 Hz, C5), 153.27 (d, 4.88 Hz, C2). 31P NMR (n20)
+ 14.86. P o t e n t i o m e t r i c Mol. W t . 203.54. Calcd 204.
4 16
DHAWAN AM) REDMORE
Anal. C a l c d f o r C7Hq05P:
C, 41.18;
Found:
H, 4.42; P, 15.20.
C, 41.18; H, 4.59;
P, 15.24.
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REFERENCES 1.
F r e e d m a n , L. D.; Doak, G. 0.; P e t i t e , E. L.; 3. Org. C h e m . 1960,2, 140.
2.
Lukin A. XI.; a n d Kalanina, 1.
3.
Doak and F r e e d m a n (J. Am. C h e m . SOC. 195?,
n.;
Zh. Obshch. Khim. 1960,2, 1597.
3, 753) O b t a i n e d
'2-
aminophenyl) phosphonic acid under conditions s i m i l a r to t h a t used by Lukin and Kalanina (Ref. 2). R e d m o r e , D.; J. Org. chern. 1984, E, 4018.
4.
Dhawan, B.;
5.
Gajda, T.; Zwierzak, A.; Synthesis, 1976, 243.
6.
Our product posseses p r o p e r t i e s in a g r e e m e n t with Freedman's p r o d u c t (Ref. 1) b u t n o t with t h e p r o d u c t o b t a i n e d by Lukin a n d Kalanina (Ref. 21.