Palladium-catalyzed carbonylation and coupling reactions of aryl chlorides and amines

Article abstract of DOI:10.1021/jo960861j

The palladium-catalyzed amidation of electron-deficient aryl chlorides proceeds readily in the presence of low CO pressures and a slight excess of an iodide salt. The rates of amidation are accelerated over those without added salt, and iodide is preferred over bromide or chloride. More electron-rich aryl chlorides were not effectively amidated, either with or without added iodide. We postulate that an intermediate anionic palladium(0) iodide complex is responsible for the enhanced reactivity.

Full text of DOI:10.1021/jo960861j

7482
J . Org. Chem. 1996, 61, 7482-7485
P a lla d iu m -Ca ta lyzed Ca r bon yla tion a n d Cou p lin g Rea ction s of
Ar yl Ch lor id es a n d Am in es
Robert J . Perry* and B. David Wilson
Imaging Research and Advanced Development, Eastman Kodak Company,
Rochester, New York 14650-1705
Received May 10, 1996X
The palladium-catalyzed amidation of electron-deficient aryl chlorides proceeds readily in the
presence of low CO pressures and a slight excess of an iodide salt. The rates of amidation are
accelerated over those without added salt, and iodide is preferred over bromide or chloride. More
electron-rich aryl chlorides were not effectively amidated, either with or without added iodide. We
postulate that an intermediate anionic palladium(0) iodide complex is responsible for the enhanced
reactivity.
In tr od u ction
NaI.13 In that work, nickel catalyzed the conversion of
a small amount of aryl chloride to aryl iodide, which
subsequently reacted with palladium.
We recently found that high molecular weight ara-
mids,1 polyimides,2 poly(amide-ols),3 and poly(imide-
amides)4 could be readily formed by the palladium-
catalyzed carbonylation and condensation of diamines
and aromatic diiodides. These polymerization reactions
were efficient, but a concern over the expense of prepar-
ing the aromatic diiodides prompted an examination of
alternate monomers for these types of polymer syntheses.
We recently found that a chloroiodophthalimide mono-
mer was sufficiently reactive in the presence of a pal-
ladium catalyst to undergo carbonylation and coupling
reactions with diamines to give high molecular weight
poly(imide-amides) (eq 1).14 The presence of iodide ion
enhanced the polymerization rate and suggested that
other aryl chlorides could be activated by iodide, thus
providing a general route for the amidation of aromatic
chlorides. Reported herein are the results of our study.
Chloro-substituted monomers were of interest because
of their low cost, ease of preparation, and stability. While
palladium-mediated carbonylations proceed readily with
bromo- and iodoaromatic compounds, aromatic chlorides
are generally less reactive. The use of high temperatures
to induce oxidative addition has led to catalyst decom-
position,5 although a temperature-resistant supported
Pd(0) catalyst in the form of 5% Pd/C with K2Cr2O7 was
found to be effective in carbonylation reactions of chlo-
robenzenes.6 More commonly, aromatic chlorides have
been activated through the introduction of Cr(CO)3
moieties7 or other electron-withdrawing substituents,5 or
inductive effects.8 An alternate method of carbonylating
aryl chlorides has been to use strongly basic and steri-
cally demanding ligands on palladium, such as triiso-
propylphosphine, tricyclohexylphosphine,9 or bis(diiso-
propylphosphino)propane.10 Carbonylation of aromatic
chlorides has also been achieved with nickel catalysts11
and with cobalt complexes.12 Another means of activat-
ing aromatic chlorides utilized a Ni/Pd system containing
Resu lts a n d Discu ssion
We initially investigated the carbonylation reaction of
4-chloro-N-phenylphthalimide, 1a , with aniline (eq 2).
* Current Address: GE Silicones, General Electric Company, 260
Hudson River Road, Waterford, NY 12188.
X Abstract published in Advance ACS Abstracts, October 1, 1996.
(1) (a) Perry, R. J .; Turner, S. R.; Blevins, R. W. Macromolecules
1993, 26, 1509. (b) Turner, S. R.; Perry, R. J .; Blevins, R. W.
Macromolecules 1992, 25, 4819.
(2) Perry, R. J .; Turner, S. R. Makromol. Chem., Macromol. Symp.
1992, 54/55, 159.
(3) Perry, R. J .; Wilson, B. D. Macromolecules 1994, 27, 40.
(4) Perry, R. J .; Turner, S. R.; Blevins, R. W. Macromolecules 1994,
27, 4058.
(5) Fitton, P.; Rick, E. A. J . Organomet. Chem. 1971, 28, 287.
(6) Dufaud, V.; Thivolle-Cazat, J .; Basset, J . M. J . Chem. Soc., Chem.
Commun. 1990, 426.
At 120 °C and elevated CO pressures (95 psig), condi-
tions under which the iodo analogue, 1b, rapidly reacted,
(7) (a) Mutin, R.; Lucas, C.; Thivolle-Cazat, J .; Dufaud, V.; Dany,
F.; Basset, J . M. J . Chem. Soc., Chem. Commun. 1988, 896. (b) Dany,
F.; Mutin, R.; Lucas, C.; Dufaud, V.; Thivolle-Cazat, J .; Basset, J . M.
J . Mol. Catal. 1989, 51, L15. (c) Dufaud, V.; Thivolle-Cazat, J .; Basset,
J . M.; Mathieu, R.; J aud, J .; Waissermann, J . Organometallics 1991,
10, 4005. (d) Scott, W. J . J . Chem. Soc., Chem. Commun. 1987, 1755.
(8) Takeuchi, R.; Suzuki, K.; Sato, N. J . Mol. Catal. 1991, 66, 277.
(9) (a) Huser, M.; Youinou, M.-T.; Osborn, J . A. Angew. Chem., Int.
Ed. Engl. 1989, 28, 1386. (b) Grushin, V. V.; Alper, H. J . Chem. Soc.,
Chem. Commun. 1992, 611.
(10) (a) Ben-David, Y.; Portnoy, M.; Milstein, D. J . Chem. Soc.,
Chem. Commun. 1989, 1816. (b) Ben-David, Y.; Portnoy, M.; Milstein,
D. J . Am. Chem. Soc. 1989, 111, 8742.
(11) Cassar, L.; Foa, M. J . Organomet. Chem. 1973, 51, 381.
(12) (a) Brunet, J .-J .; Sidot, C.; Caubere, P. J . Org. Chem. 1983,
48, 1166. (b) Foa, M.; Francalanci, F.; Bencini, E.; Gardano, A. J .
Organomet. Chem. 1985, 285, 293. (c) Foa, M.; Francalanci, F. J . Mol.
Catal. 1987, 41, 89. (d) Kudo, K.; Shibata, T.; Kashimura, T.; Mori, S.;
Sugita, N. Chem. Lett. 1987, 577.
(13) Bozell, J . J .; Vogt, C. E. J . Am. Chem. Soc. 1988, 110, 2655.
S0022-3263(96)00861-4 CCC: $12.00 © 1996 American Chemical Society

Coupling Reactions of Aryl Chlorides and Amines
J . Org. Chem., Vol. 61, No. 21, 1996 7483
F igu r e 1. Effect of CO pressure and iodide on amidation of
1a with aniline. Reaction in DMAc (0.22 M) at 120 °C, 1.2
equiv of DBU, 3% PdCl2L2, 6% L (L ) PPh3). Key: 9, 5 psig of
CO, 1.2 equiv of NaI; 0, 5 psig of CO, no NaI; b, 95 psig of
CO, 1.2 equiv of NaI; O, 95 psig of CO, no NaI.
F igu r e 3. Effect of halide on amidation of 1a with aniline.
Reaction in DMAc (0.22 M) at 120 °C, 1.2 equiv of DBU, 3%
PdCl2L2, 6% L (L ) PPh3), 1.2 equiv of LiX, 5 psig of CO. Key:
b, LiCl; 2, LiBr; 9, LiI.
90% reaction. While the reactions were slower, they were
still accelerated over the reaction without any added
iodide.
A comparison of the different halides showed that
iodide was the best in terms of rate enhancement. When
LiCl, LiBr, and LiI were added to the reaction of 1a and
aniline, the iodide reaction was complete within 0.4 h
(Figure 3). The bromide-containing reaction required 0.8
h and the chloride, 1.0 h, to reach the same level. The
lithium salts were examined because of the greater
solubility of LiCl in the reaction medium than that of
NaCl.
Armatore15 and Negishi16 have described the formation
of low coordinative zero-valent palladium complexes
stabilized by halide anions. We suggest that similar
palladium(0) ate complexes of the form [LnPd(0)I]-Na+
are being formed in our system and that these reactive
species are enhancing the oxidative addition reaction to
the aryl chloride.
Similar [LnPd(0)Cl]-Li+ complexes have been proposed
to be the effective agents in cross-coupling reactions of
aryl triflates and organostannanes.17 The formation of
these anionic Pd(0) complexes and their reported en-
hanced reactivity in oxidative addition reactions provides
an explanation for the overall rate increase seen in the
amidation reactions. Oxidative addition reactions have
been shown to be the slow step in the carbomethoxylation
of aromatic bromides.18 Since the amidation reaction is
an analogous carbonylation reaction and given that
oxidative addition is slower to aryl chlorides than to
bromides, an increase in the rate of this initial step
results in an increase in the overall rate. The proposed
reaction scheme is outlined in Scheme 1.
F igu r e 2. Effect of iodide concentration on amidation of 1a
with aniline. Reaction in DMAc (0.22 M) at 120 °C, 1.2 equiv
of DBU, 5 psig of CO, 3% PdCl2L2, 6% L (L ) PPh3). Key: O,
no NaI; b, 0.1 equiv of NaI; 0, 0.5 equiv of NaI; 9, 1.2 equiv
of NaI; 2, 5.0 equiv of NaI.
some amidation of 1a to 2 occurred, but the reaction was
slow and tapered off after 6 h (Figure 1). Under the same
conditions, but with 1.2 equiv of NaI present (based on
1a ), amidation occurred more quickly with 90% conver-
sion in ca. 3 h. When the CO pressure was decreased to
5 psig and NaI omitted from the reaction, the amidation
reaction had nearly the same rate as that seen for the
high CO pressure with NaI. The fastest reaction was
observed at 5 psig CO and in the presence of a slight
excess of NaI in which 95% conversion had been achieved
within 0.5 h.
(14) Perry, R. J .; Turner, S. R.; Blevins, R. W. Macromolecules 1995,
28, 2607.
(15) (a) Amatore, C.; Azzabi, M.; J utand, A. J . Organomet. Chem.
1989, 363, C41. (b) Amatore, C.; Azzabi, M.; J utand, A. J . Am. Chem.
Soc. 1991, 113, 8375. (c) Amatore, C.; J utand, A.; Suarez, A. J . Am.
Chem. Soc. 1993, 115, 9531.
(16) Negishi, E.; Takahashi, T.; Akiyoshi, K. J . Chem. Soc., Chem.
Commun. 1986, 1338.
(17) Scott, W. J .; Stille, J . K. J . Am. Chem. Soc. 1986, 108 , 3033.
(18) Moser, W. R; Wang, A. W.; Kildahl, N. K. J . Am. Chem. Soc.
1988, 110, 2816.
To determine the optimum loading of NaI, a series of
reactions were run with varying iodide concentrations.
The fastest reactions were seen when at least a stoichio-
metric amount of iodide was present. Greater than 90%
reaction was achieved in 0.5 h or less with 1.2-5 equiv
of NaI (Figure 2). With 0.5 equiv of iodide in the reaction,
the time for 90% completion of the reaction increased to
1.5 h. At lower levels (0.1 equiv), 2.5 h was needed for
(19) (a) Brown, H. C.; Okamoto, Y. J . Am. Chem. Soc. 1958, 80, 4979.
(b) Lange’s Handbook of Chemistry, 14th ed.; Dean, J . A., Ed.; McGraw
Hill Book Co.: New York, 1992; pp 9.2-9.7.

7484 J . Org. Chem., Vol. 61, No. 21, 1996
Perry and Wilson
Sch em e 1
Ta ble 1. Op tim iza tion of Rea ction of 5 w ith An ilin ea
Ta ble 2. Effect of Su bstitu en t on Am id a tion Rea ction a
yieldc (%)
b
entry
Y
σp
1
2
3
4
5
SO2Ph
CN
CF3
COMe
COPh
COOMe
F
0.67d
0.66
0.54
0.50
0.46
91
62
78
71
82
59
CO
%
%
salt
(equiv)
pressure time
(psig)
%
entry catalystb ligandc
(h) productd
6
7
0.39
0.06
<15% conversion
<3% conversion
<12% conversion
<1% conversion
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
3
3
3
3
3
3
3
3
3
3
3h
3
3
3
6
6
6
6
6
6
6
6
12
95
5
95
5
95
5
5
5
5
5
5
7
7
4
8
29
6
8
9
10
11
H
Ph
Me
OMe
0.00
-0.01
-0.17
-0.27
0.10 NaI
0.10 NaI
1.00 NaI
1.00 NaI
1.00 Bu4N+I-
1.00 KI
1.00 NaI
1.00 NaI
1.00 NaI
1.00 NaI
1.00 NaI
1.00 NaI
32
23
23
23
23
19
24
24
23
24
24
50
57
82
36
75
88
44
76
15
66
98
a
Reactions run for 24 h at 115 °C using 3% PdCl2L2 and 6%
DPPE at 5 psig of CO. bHammett para substituent constants.19
c Isolated, purified yields; percent conversion was determined by
d
GC and products were not isolated. Estimated from Hammett
meta constant.
6e
5
5
5
showed essentially quantitative formation of the desired
amide sulfone 6, after 24 h (entry 14).
6f
6g
To determine the scope and limitation of this reaction,
the optimum conditions for chlorophenyl phenyl sulfone
amidation were applied to other substrates as shown in
Table 2. Only those chlorides activated by strong electron
withdrawing groups (entries 1-6) underwent successful
amidation. GC analysis indicated complete reaction, and
the isolated, purified yields of substituted benzanilides
ranged between 60 and 90%. Weakly withdrawing
moieties and donating substituents reacted sluggishly or
not at all.
a
b
Reaction in DMAc at 115 °C with 1.2 equiv of DBU. PdCl2L2
(L ) PPh3). c PPh3. Yield of 6 as determined by GC. e Tri-o-
d
tolylphosphine as ligand. f Tri-p-tolylphosphine as ligand. 1,2-
g
h
Bis(diphenylphosphino)ethane as ligand. PdL4.
From the above experiments, it was clear that the
phthalimide group was sufficient to activate the aryl
chloride bond for oxidative addition reactions and that
iodide had a accelerating effect on the overall amidation
rate. Another such activating group is the sulfone
moiety. A series of reactions for the amidation of
4-chlorophenyl phenyl sulfone were also performed to
compare with the phthalimide. Table 1 shows that
similar trends were found. Lower CO pressures gave
higher yields of product (entries 1-6), and higher NaI
concentrations gave greater yields (entries 2, 4, and 6).
The addition of extra phosphine ligands provided a higher
yield of amide (entry 9), while the removal of these
ligands resulted in a drop in product formation (entry
10). The use of PdL4 gave results similar to PdCl2L2 with
2 PPh3 added (entry 11). These last results suggested,
at least in the case of the 4-chlorophenyl phenyl sulfone,
that the ligands were more important than in the
phthalimide case where no difference in rate or yield was
seen with variation in PPh3 concentration. Tri-o- and tri-
p-tolylphosphine were added as ligands with no advanta-
geous effects (entry 12-13). However, the dichelating
phosphine, 1,2-bis(diphenylphosphino)ethane (DPPE),
Con clu sion
We have shown that the palladium-catalyzed amida-
tion of electron, deficient aryl chlorides proceeds readily
in the presence of low CO pressures and a slight excess
of an iodide salt. The rates of amidation are accelerated
over those without added salt, and iodide is preferred
over bromide or chloride. More electron-rich aryl chlo-
rides were not effectively amidated, either with or
without added iodide. We postulate that an intermediate
anionic palladium(0) iodide complex is responsible for the
enhanced reactivity.
Exp er im en ta l Section
Gen er a l P r oced u r es. Reactions were performed in a 120
mL pressure reaction vessel (containing a Teflon-coated stir-
bar), fitted with a pressure gauge, a pressure release valve, a
gas inlet, and a straight ball valve for degassing and sample

Coupling Reactions of Aryl Chlorides and Amines
J . Org. Chem., Vol. 61, No. 21, 1996 7485
withdrawal, in a well-ventilated hood and behind safety
shields. Reactions were monitored on an HP 5890 gas chro-
matograph using a 15 m, 0.25 µM DB-5 column (0.32 mm i.d.)
and a flame ionization detector. Helium flow rate through the
column was 4.0 mL/min. The GC parameters employed for
analysis were as follows: injection port, 300 °C; detector, 350
°C; temperature ramp from 50 °C (hold 1 min) to 300 °C (hold
10 min) at 20 °C/min. Biphenyl was used as an internal
standard to determine GC yields. 1H NMR and 13C NMR
spectra were acquired on a 300 MHz spectrometer using CDCl3
or DMSO-d6 as both solvent and reference. 31P NMR spectra
were acquired on a 120 MHz spectrometer using DMF-d7 as
solvent and H3PO4 as an external reference. Fourier transform
infrared spectra were recorded as KBr pellets. Elemental
analyses were performed by the Analytical Technology Divi-
sion of Eastman Kodak Company.
Ch em ica ls. Aniline (dried over CaH2) and 1,8-diazabicyclo-
[5.4.0]undec-7-ene (DBU) were fractionally distilled under
reduced pressure. Triphenylphosphine (PPh3) was recrystal-
lized from hexanes. NaI, KI, and NaBr were dried at 120 °C
in vacuo. CO (Air Products, UPC grade), bis(triphenylphos-
phine)palladium(II) chloride (PdCl2L2), tetrakis(triphenylphos-
phine)palladium (PdL4), tri(o-tolyl)phosphine, tri(p-tolyl)-
phosphine, 1,2-bis(diphenylphosphino)ethane (DPPE), N,N-
dimethylacetamide (DMAc, anhydrous), tetra-n-butylammo-
nium iodide, 4-chlorophenyl phenyl sulfone, 4-chlorobenzotri-
fluoride, methyl 4-chlorobenzoate, 1-chloro-4-fluorobenzene,
4-chlorotoluene, 4-chloroanisole (all Aldrich), p-chlorobenzoni-
trile, 4′-chloroacetophenone, chlorobenzene (all Eastman Kodak),
4-chlorophthalic anhydride (Oxy Chem), and 4-chlorobiphenyl
(Alfa) were used as received. 4-Iodophthalic anhydride was
prepared as described previously.13
P r ep a r a tion of Sta r tin g Ma ter ia ls. 4-Ch lor o-N-p h e-
n ylp h th a lim id e, 1a . A solution of 4-chlorophthalic anhydride
(9.12 g, 50 mmol), aniline (4.65 g, 50 mmol), pyridine (12.01
g, 152 mmol), and DMAc (40 mL) was heated at 70 °C for 1 h
under argon. Acetic anhydride (20.0 g, 196 mmol) was added,
and the solution was allowed to stir at 80 °C for a total of 4 h.
The reaction mixture was cooled to ca. 5 °C and the crystalline
solid removed by filtration, washed with acetone and methanol,
and dried in vacuo to give 9.0 g (70%) product that was
recrystallized from acetic anhydride: mp 187-189 °C (lit. mp
189.5-191 °C);20 1H NMR (CDCl3) δ 7.90 (d, J ) 1.6 Hz, 1),
7.88 (d, J ) 8.0 Hz, 1), 7.73 (dd, J ) 8.0, 1.6 Hz, 1), 7.50 (m,
2), 7.41 (m, 3); 13C NMR (CDCl3) {1H} d 166.2, 165.9 141.1,
134.4, 133.5, 131.5, 129.9, 129.1, 128.2, 126.4, 124.9, 124.1.
4-Iod o-N-p h en ylp h th a lim id e, 1b. As described above,
4-iodophthalic anhydride (2.0 g, 7.3 mmol), aniline (665 µL,
7.3 mmol), pyridine (2.1 mL, 25.5 mmol), and DMAc (10 mL)
were heated at 80 °C for 2 h, followed by continued heating in
the presence of acetic anhydride (2.75 mL, 29.2 mmol) for 16
h. MeOH (5 mL) was added to the warm solution, which was
then cooled to room temperature. The crystalline solid was
removed by filtration, washed with MeOH, and dried in vacuo
to give 1.96 g (77%) of product. The filtrate was concentrated
and cooled to 0 °C to afford another 300 mg (11%) of product:
total yield 88%; mp 178-179 °C; 1H NMR (CDCl3) δ 8.27 (d, J
) 1.0 Hz, 1), 8.13 (dd, J ) 7.5, 1.0 Hz, 1), 7.65 (d, J ) 7.9 Hz,
1), 7.49 (m, 2), 7.40 (m, 3); 13C NMR (CDCl3) {1H} δ 166.6,
165.7 143.3, 133.1, 132.8, 131.5, 131.0, 129.1, 128.2, 126.4,
124.9, 101.1. Anal. Calcd for C14H8INO2: C, 48.16; H, 2.31;
N, 4.01. Found: C, 47.81; H, 2.39; N, 3.95.
Hz, 2), 7.46 (m, 5), 7.35 (t, J ) 7.8 Hz, 2), 7.11 (t, J ) 7.3 Hz,
1); 13C NMR (DMSO-d6) {1H} δ 166.3, 166.2, 163.4, 140.2,
138.5, 134.1,133.6, 131.7, 131.6, 128.7,128.4, 127.9, 127.1,
124.0, 123.4, 122.0, 120.5. Anal. Calcd for C21H14N2O3: C,
73.68; H, 4.12; N, 8.18. Found: C, 73.71; H, 4.10; N, 7.94.
(4-Ca r boxya n ilin o)p h en yl P h en ylsu lfon e. A pressure
bottle was charged with 4-chlorophenyl phenyl sulfone (1.387
g, 5.5 mmol), aniline (500 µL, 5.5 mmol), PdCl2L2, (116 mg,
0.16 mmol), DPPE (131 mg, 0.3 mmol), NaI (823 mg, 6.6
mmol), DBU (985 µL, 6.6 mmol) and DMAc (17 mL). The
mixture was degassed and charged with 5 psig of CO and then
heated to 115 °C for 6 h. GC analysis of the reaction indicated
all the starting material had been consumed. The solution
was filtered through Celite, concentrated in vacuo, and then
slurried with MeOH to give an off-white solid. The solid was
washed extensively with MeOH and dried to give 1.54 g of
product (83%). The filtrate was concentrated and subjected
to chromatography on silica gel, eluting with 1:1 hexanes:
EtOAc, to give an additional 147 mg (8%) product: total yield
1
91%; mp 206-207.5 °C; H NMR (CDCl3) δ 10.43 (s, 1), 8.09
(s, 4), 7.98 (d, J ) 8.0 Hz, 2), 7.65 (m, 5), 7.33 (t, J ) 7.5 Hz,
2), 7.08 (t, J ) 7.0 Hz, 1); 13C NMR (CDCl3) {1H} δ 164.2, 143.3,
140.6, 139.6, 138.7, 133.9, 129.8, 128.9, 128.6, 127.4, 124.0,
120.3. Anal. Calcd for C19H15NO3S: C, 67.64; H, 4.48; N, 4.15.
Found: C, 67.28; H, 4.60; N, 4.15.
The rest of the amidation reactions were performed on the
same scale and in a similar manner, except as noted below.
4-Cya n oben za n ilid e. After 17 h reaction time, the reac-
tion mixture was filtered, concentrated, dissolved in hot
toluene, and chromatographed on silica gel eluting with
toluene. The product obtained was recrystallized from toluene
to give 761 mg of product (62%): mp 179.5-180 °C (lit.21 mp
1
175-176 °C); H NMR (CDCl3) δ 10.45 (s, 1), 8.08 (d, J ) 8.3
Hz, 2), 8.03 (d, J ) 8.3 Hz, 2), 7.75 (d, J ) 8.0 Hz, 2), 7.34 (t,
J ) 7.8 Hz, 2), 7.10 (t, J ) 7.3 Hz, 1); 13C NMR (CDCl3) {1H}
δ 164.1, 138.9, 138.7, 132.4, 128.6, 128.4, 124.0, 120.4, 118.4,
113.8.
4-(Tr iflu or om eth yl)ben za n ilid e. After recrystallization
from toluene, as above, 1.136 g (78%) of product was ob-
tained: mp 202-203 °C (lit.22 mp 198 °C); 1H NMR (CDCl3) δ
10.44 (s, 1), 8.12 (d, J ) 8.2 Hz, 2), 7.88 (d, J ) 8.2 Hz, 2),
7.75 (d, J ) 7.9 Hz, 2), 7.34 (t, J ) 7.8 Hz, 2), 7.10 (t, J ) 7.4
Hz, 1).
4-Acetylben za n ilid e. After recrystallization from toluene,
as above, 933 mg (71%) of product was obtained: mp 197-
198 °C (lit.23 mp 188-189 °C); 1H NMR (CDCl3) δ 10.40 (s, 1),
8.05 (s, 4), 7.77 (d, J ) 8.1 Hz, 2), 7.34 (t, J ) 7.8 Hz, 2), 7.09
(t, J ) 7.3 Hz, 1), 2.61 (s, 3); 13C NMR (CDCl3) {1H} δ 197.6,
164.7, 138.9, 138.8, 138.7, 128.6, 128.1, 127.9, 123.9, 120.4,
26.9.
4-Ben zoylben za n ilid e. After recrystallization from tolu-
ene, as above, 1.351 g (82%) of product was obtained: mp 161-
1
161.5 °C; H NMR (CDCl3) δ 10.44 (s, 1), 8.08 (d, J ) 8.2 Hz,
2), 7.83 (d, J ) 8.2 Hz, 2), 7.77 (m, 4), 7.69 (t, J ) 7.5 Hz, 1),
7.56 (t, J ) 7.5 Hz, 2), 7.34 (t, J ) 7.8 Hz, 2), 7.10 (t, J ) 7.3
Hz, 1); 13C NMR (CDCl3) {1H} δ 195.3, 164.7, 139.4, 138.9,
138.2, 136.6, 133.0, 129.6, 129.4, 128.6, 127.8, 123.5, 120.4.
Anal. Calcd for C20H15NO2: C, 79.72; H, 5.02; N, 4.65.
Found: C,79.53; H, 5.15; N, 4.65.
4-Car bom eth oxyben zan ilide. After recrystallization from
toluene, as above, 821 mg (59%) product was obtained: mp
191.5-192 °C (lit.24 mp 192-193 °C); 1H NMR (CDCl3) δ 10.41
(s, 1), 8.05 (s, 4), 7.77 (d, J ) 8.0 Hz, 2), 7.38 (t, J ) 7.8 Hz, 2),
7.09 (t, J ) 7.3 Hz, 1), 3.86 (s, 3); 13C NMR (CDCl3) {1H} δ
165.6, 164.6, 139.0, 138.8, 132.0, 129.1, 128.6, 128.0, 123.9,
120.4, 52.3.
Rep r esen ta tive Am id a tion Rea ction s. N-P h en yl-4-
(ca r boxya n ilin o)p h th a lim id e (2). A pressure bottle was
charged with 4-chloro-N-phenylphthalimide, 1 (566 mg, 2.19
mmol), aniline (200 µL, 2.19 mmol), PdCl2L2, (46 mg, 0.066
mmol), PPh3 (35 mg, 0.132 mmol), NaI (395 mg, 2.63 mmol),
DBU (395 µL, 6.6 mmol), and DMAc (15 mL). The mixture
was degassed and charged with 5 psig of CO and then heated
to 115 °C for 16 h. The solution was filtered through Celite,
concentrated in vacuo, and then slurried with MeOH to give
an off-white solid. The solid was washed extensively with
MeOH and dried to give 615 mg of product (82%): mp 266.5-
268 °C; 1H NMR (DMSO-d6) δ 10.60 (s, 1), 8.50 (s, 1), 8.41
(dd, J ) 7.5, 1.0 Hz, 1), 8.08 (d, J ) 7.7 Hz, 1), 7.78 (d, J ) 7.8
J O960861J
(21) Bharucha, K. R.; Shah, R. C. J . Univ. Bombay 1949, 17A, 76.
(22) Yagupol’skii, L. M.; Gruz, B. E. Ukr. Khim. Zh. 1957, 23, 634.
CA52:9980a.
(23) Suzuki, H.; Tsuji, J .; Hiroi, Y.; Sato, N.; Osuka, A. Chem. Lett.
1983, 449.
(20) Williams, F. J .; Donohue, P. E. J . Org. Chem. 1977, 42, 3414.
(24) Schoenberg, A.; Heck, R. F. J . Org. Chem. 1974, 39, 3327.