Palladium-catalyzed cyanation of aryl and heteroaryl iodides with copper(i) cyanide

Article abstract of DOI:10.1039/a903345i

The palladium-catalyzed cyanation of aryl and heteroaryl iodides or bromides using copper(i) cyanide as a cyano group source afforded the corresponding aryl and heteroaryl cyanides in good yields.

Full text of DOI:10.1039/a903345i

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Palladium-catalyzed cyanation of aryl and heteroaryl iodides with
copper(I) cyanide
Takao Sakamoto* and Kazutoshi Ohsawa
Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki-aza-Aoba, Aoba-ku,
Sendai 980-8578, Japan
Received (in Cambridge) 27th April 1999, Accepted 28th June 1999
The palladium-catalyzed cyanation of aryl and heteroaryl iodides or bromides using copper() cyanide
as a cyano group source afforded the corresponding aryl and heteroaryl cyanides in good yields.
gave indole-3-carbonitriles. These reactions are restricted to
Introduction
only proceed at the electrophilically active positions. They are
not general or efficient preparative methods of aryl and hetero-
aryl cyanides.
Since the cyano group is a stable and useful functional group,
which can be transformed to various other functional groups
such as acyl, carboxy, formyl, carbamoyl, etc., many synthetic
methods for aryl and heteroaryl cyanides have been studied.
Among them, the following methods are known as classical
methods for the direct introduction of a cyano group to arenes
and heteroarenes: the cyanation of aryl and heteroaryl halides
with copper() cyanide (CuCN), the Reissert–Henze cyanation
of π-deficient heteroaromatic N-oxides, and the electrophilic
cyanation of π-sufficient heteroaromatics.
The cyanation of aryl and heteroaryl halides with CuCN has
been used for the synthesis of the corresponding cyanides, and
this method can be generally applicable to the iodo and bromo
derivatives of arenes and π-sufficient heteroarenes. However,
the reaction conditions, e.g., heating in DMF or quinoline, are
relatively severe. The reaction of α- or γ-halogeno π-deficient
heteroarenes affords the products in low yields and is only
practically applicable to the β-halogeno derivatives.1
The transition metal-catalyzed cyanation of aryl halides and
triflates is a useful modern method to prepare aryl cyanides. In
particular, palladium-catalyzed cyanation is known to have
generality in synthesis of benzonitrile derivatives, and potas-
sium,4 sodium,5 trimethylsilyl,6 and zinc cyanide7 as the cyano
group source have been used in the cyanation. The reported
palladium-catalyzed cyanations were centred on the benzene
derivatives, and there is no report on heteroaromatic derivatives
except for the halogenopyrazines4e,f and 3-bromopyridine.8
In order to establish a cyanation method generally applicable
to arenes, π-deficient, and π-sufficient heteroarenes and to find
a new cyano group source, we studied the palladium-catalyzed
cyanation of aryl and heteroaryl halides using CuCN as the
cyano group source. Recently, a copper() species-catalyzed
reaction using sodium cyanide as a cyano group source8 has
been reported and as in connection with our study.
Although the Reissert–Henze cyanation of π-deficient
heteroarene N-oxides2 generally gives the corresponding
cyanides in good yields, and the modification using trimethyl-
silyl cyanide instead of alkali metal cyanides has been
developed, the positions of the cyano group are principally
restricted to the α-positions with respect to the N-oxide groups.
A few direct electrophilic cyanations of π-sufficient hetero-
aromatics are also known;3 for example, the electrophilic
substitution reaction of indoles with (ethoxycarbonylimino)-
triphenylphosphorane or triphenylphosphine–thiocyanogen
At first, we examined the reaction conditions using
4-methoxyiodobenzene 1a as the substrate, tris(dibenzylidene-
acetone)dipalladium [Pd2(dba)3] as the palladium(0) catalyst,
which is known to be more stable than tetrakis(triphenyl-
phosphine)palladium [Pd(PPh3)4], and diphenylphosphino-
ferrocene (DPPF) as the ligand.
As shown in Table 1, a DMF solution of 1a and CuCN in the
presence of Pd2(dba)3 and DPPF was heated at 120 ЊC for 2 h
(Run 1) to give 4-methoxybenzonitrile 3a in 80% yield. In order
to find milder reaction conditions and an easier isolation oper-
Table 1 Palladium-catalyzed cyanation of 4-methoxyhalogenobenzenes 1a and 2a with CuCN
X
CN
i
MeO
MeO
1a: X=I
3a
2a: X=Br
Reagents and conditions: i, CuCN, Pd2(dba)3, DPPF, 1,4-dioxane, reflux.
Run
X
Additive
Solvent
Temp. (T/ЊC)
Time (t/h)
Yield (%)
1
2
3
4
5
6
7
8
9
I
I
I
I
I
I
I
Br
Br
None
None
DMF
Dioxane
DMF
DMF
Dioxane
THF
MeCN
DMF
Dioxane
120
Reflux
120
2
1
1
2
2
1
2
4
3
80
39
85
78
82
93
87
29
91
Et4NCN
Et4NCN
Et4NCN
Et4NCN
Et4NCN
Et4NCN
Et4NCN
100
Reflux
Reflux
Reflux
120
Reflux
J. Chem. Soc., Perkin Trans. 1, 1999, 2323–2326
2323

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ation for the products, the reaction in 1,4-dioxane at the reflux
temperature (101 ЊC, Run 2) was examined, but the yield of 3a
decreased to 39%. When the above DMF solution containing
tetraethylammonium cyanide (Et4NCN), which was not an
effective cyano group source, as an additive was heated at
100 ЊC or 120 ЊC, the yields of 3a were not significantly changed
(Runs 3 and 4). In the reaction containing Et4NCN in 1,4-
dioxane, however, the yield was dramatically improved (Run 5).
These reaction conditions were found to be effective for the
palladium-catalyzed reaction of 4-methoxybromobenzene 2a
with CuCN (Run 9). Although the reaction mixture containing
Et4NCN in other solvents such as THF and acetonitrile (Run 6
and 7) also gave 3a in good yields, these solvents were not effect-
ive for the reaction of heteroaryl halides such 3-iodo-1-
(phenylsulfonyl)indole 4b as will be described below. Therefore,
we selected 1,4-dioxane as the reaction solvent.
For the reaction of the bromo derivative 2a, similar results
were obtained, namely refluxing in 1,4-dioxane for 3 h gave 3a
in 91% yield. Based on these experiments, we decided that
refluxing in 1,4-dioxane in the presence of Et4NCN should be
selected as the reaction conditions for the palladium-catalyzed
cyanation of aryl halides with CuCN using Pd2(dba)3 and
DPPF.
except for 2-nitrobromobenzene, although the reason for the
low yield in this case is not clear at present.
The palladium-catalyzed cyanation using CuCN as a cyano
group source was applied to heteroaryl halides. N-(Phenyl-
sulfonyl)indoles 4a,b, the pyrrole derivatives 5a,b, and quino-
line derivatives 7 and 8a–c were used as representative
π-sufficient and π-deficient heteroarenes. The results in Table 3
show that the reaction using heteroaryl iodides 4–6, 8 gave the
corresponding nitriles 9–12 in good yields without using
Et4NCN as an additive. In the case of 2-bromoquinoline 7,
however, the addition of Et4NCN to the reaction mixture gave
quinoline-2-carbonitrile 12a in 77% yield.
X
Me
X
X
N
N
Me
N
N
SO2Ph
SO2Ph
SO2Ph
6: X=I
11: X=CN
5a: X=2-I
4a: X=2-I
5b: X=3-I
4b: X=3-I
10a: X=2-CN
10b: X=3-CN
9a: X=2-CN
9b: X=3-CN
Next, the reaction conditions were applied to halogenoben-
zene derivatives having substituents at the 2- or 4-position. As
shown in Table 2, the iodo- and bromobenzenes were trans-
formed into the corresponding benzonitriles in 56–94% yields
X
N
R
Table 2 Palladium-catalyzed cyanation of halogenobenzenes 1a–f and
2a–f with CuCN
7 : X=2-Br, R=H
12a: X=2-CN, R=H
12b: X=3-CN, R=H
12c: X=4-CN, R=Me
8a: X=2-I, R=H
8b: X=3-I, R=H
8c: X=4-I, R=Me
X
CN
i
R
R
1a-f, 2a-f
3a-f
Since the reaction of halogenoaromatics, especially iodo- or
bromoaromatics, with CuCN is known as a classical method for
the synthesis of aromatic nitriles as already described above, we
finally examined the reaction of the halogenoaromatics used in
this study with CuCN in order to confirm that our method is a
palladium-catalyzed reaction. Namely, the reaction of aryl
bromides or iodides with CuCN in DMF at 120 ЊC or in 1,4-
dioxane at reflux in the presence or absence of Et4NCN gave the
corresponding nitriles in zero or low yields and the starting
halogenoaromatics were recovered in high amounts in almost
all reactions (Table 4).
The cyanation reaction described in this paper is con-
sidered to proceed as follows. An arylpalladium halide which
forms by oxidative addition reaction of an aryl halide with a
palladium(0) species transforms to an arylpalladium cyanide by
ligand exchange reaction with CuCN. The arylpalladium
cyanide gives an aryl cyanide by reductive elimination reaction.
Reagents and conditions: i, CuCN, Et4NCN, Pd2(dba)3, DPPF, 1,4-
dioxane, reflux.
Compd.
R
X
Time (t/h)
Yield (%)
1a
1b
1c
1d
1e
1f
2a
2b
2c
2d
2e
2f
4-OMe
4-CO2Me
4-NO2
2-OMe
2-CO2Me
2-NO2
4-OMe
4-CO2Me
4-NO2
2-OMe
2-CO2Me
2-NO2
I
I
I
I
I
I
Br
Br
Br
Br
Br
Br
2
1
2
1
1
1
3
1
3
1
1
1
82
88
65
94
88
67
91
89
56
76
83
23
Table 3 Palladium-catalyzed cyanation of halogenoheteroaromatics 4–8 with CuCN
i
HeteroArX
HeteroArCN
9–12
4–8
Reagents and conditions: i, CuCN, Pd2(dba)3, DPPF, 1,4-dioxane, reflux.
HeteroArX
Additive
Time (t/h)
Yield (%)
2-Iodo-1-(phenylsulfonyl)indole 4a
3-Iodo-1-(phenylsulfonyl)indole 4b
2-Iodo-1-(phenylsulfonyl)pyrrole 5a
3-Iodo-1-(phenylsulfonyl)pyrrole 5b
4-Iodo-3,5-dimethyl-1-(phenylsulfonyl)pyrazole 6
2-Bromoquinoline 7
None
None
None
None
None
None
Et4NCN
None
None
None
3
4
1
1
1
18
1
1
1
1
94
99
97
69
90
42
77
90
91
96
2-Bromoquinoline 7
2-Iodoquinoline 8a
3-Iodoquinoline 8b
4-Iodo-2-methylquinoline 8c
2324
J. Chem. Soc., Perkin Trans. 1, 1999, 2323–2326

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Table 4 Reaction of aryl and heteroaryl halides with CuCN
ArX
CuCN
ArCN
additive, solvent temp.
Reagents and conditions: i, CuCN, 1,4-dioxane, reflux.
Compd.
Additive
Solvent
Temp. (T/ЊC)
Time (t/h)
Yield (%)a
1a
1b
1c
1d
1e
1f
2a
2a
4a
4b
5a
5b
8a
8b
8c
Et4NCN
Et4NCN
Et4NCN
Et4NCN
Et4NCN
Et4NCN
Et4NCN
Et4NCN
None
None
None
None
None
DMF
120
18
12
12
12
12
12
40
12
12
12
12
12
20
12
12
39 (20)
(96)
Dioxane
Dioxane
Dioxane
Dioxane
Dioxane
DMF
Dioxane
Dioxane
Dioxane
Dioxane
Dioxane
Dioxane
Dioxane
Dioxane
Reflux
Reflux
Reflux
Reflux
Reflux
120
Reflux
Reflux
Reflux
Reflux
Reflux
Reflux
Reflux
Reflux
trace (84)
31 (67)
trace (98)
29 (25)
1 (53)
(58)
(45)
(98)
(96)
(100)
(81)
Et4NCN
None
(99)
(88)
a Figure in parentheses are recoveries of the starting halogenoaromatics.
Conclusions
(108 mg, 0.5 mmol) gave 3b (71.6 mg, 89%). The crude product
was recrystallized from hexane–acetone to give colorless
needles, mp 66–67 ЊC (lit.,9 68 ЊC); νmax(KBr)/cmϪ1 1720, and
2250; δH 3.97 (3H, s), 7.75 (2H, d, J 8.24), 8.15 (2H, d, J 8.24);
m/z 161 (Mϩ, 34%), and 130 (100) (Found: Mϩ, 161.0522.
C9H7NO2 requires M, 161.0476).
The palladium-catalyzed cyanation of aryl and heteroaryl
halides using CuCN as the cyano group source is a general
preparative method for aromatic nitriles together with the
reported palladium-catalyzed reactions4–8 using various
inorganic and organic cyanides.
4-Nitrobenzonitrile 3c. According to the General Procedure
A, the reaction using 4-iodonitrobenzene 1c (249 mg, 1.0 mmol)
gave 3c (95.8 mg, 65%). The crude product was recrystallized
from hexane–AcOEt to give colorless plates, mp 148–150 ЊC
(lit.,9 148 ЊC); νmax(KBr)/cmϪ1 1350, 1520, and 2225; δH 7.89
(2H, d, J 8.52), 8.37 (2H, d, J 8.52); m/z 148 (Mϩ, 69%), and 102
(100) (Found: Mϩ, 148.0273. C7H4N2O2 requires M, 148.0272).
Experimental
All mps (Yazawa micro melting point BY-2) and bps are un-
corrected. IR spectra were taken on a JASCO IR-810 spectro-
photometer. 1H NMR spectra were recorded on Varian Gemini
2000 (300 MHz) and Hitachi R-300 (300 MHz) spectrometers.
Chemical shifts are expressed in δ (ppm) values with tetra-
methylsilane (TMS) as an internal reference, and coupling
constants (J) are expressed in hertz (Hz). The following
abbreviations are used: s = singlet, d = doublet, t = triplet,
m = multiplet, dd = doublet of doublet, dt = doublet of triplet.
Mass spectra (MS) and high-resolution mass spectra (HRMS)
were recorded on JMS-DX303 and JMS-AX500 instruments.
2-Methoxybenzonitrile 3d. According to the General
Procedure A, the reaction using 2-iodoanisole 1d (117 mg, 0.5
mmol) gave 3d (62.5 mg, 94%) as a colorless liquid; bp 70 ЊC/3
mmHg (lit.,9 135 ЊC/12 mmHg); νmax (neat)/cmϪ1 2225; δH 3.94
(3H, s), 6.97–6.99 (2H, m), 7.52–7.59 (2H, m); m/z 133 (Mϩ,
100%) (Found: Mϩ, 133.0538. C8H7NO requires M, 133.0527).
General procedure for the palladium-catalyzed cyanation of
halogenoarenes and halogenoheteroarenes with CuCN
Methyl 2-cyanobenzoate 3e. According to the General
Procedure A, the reaction using methyl 2-iodobenzoate 1e (262
mg, 1.0 mmol) gave 3e (142 mg, 88%). The crude product was
recrystallized from hexane–acetone to give colorless prisms, mp
47–49 ЊC (Found: C, 67.38; H, 4.38; N, 8.82. C9H7NO2 requires
C, 67.08; H, 4.38; N, 8.69%); νmax(KBr)/cmϪ1 1720, and 2225;
δH 4.01 (3H, s), 7.66–7.70 (2H, m), 7.81–7.84 (1H, m), 8.14–8.17
(1H, m); m/z 161 (Mϩ, 30%), and 130 (100) (Found: Mϩ,
161.0516. C9H7NO2 requires M, 161.0476).
A mixture of a halogenoarene or a halogenoheteroarene (1.0
mmol), CuCN (4.0 mmol), Pd2(dba)3 (0.04 mmol), DPPF (0.16
mmol), and anhydrous 1,4-dioxane (5 mL) in the presence
of (Procedure A) or in the absence of Et4NCN (1.0 mmol)
(Procedure B) was refluxed, for the time shown in Tables 2–4,
under argon atmosphere. The reaction mixture was diluted
with AcOEt and filtered through a Celite pad. The filtrate
was washed with saturated aq. NaHCO3 (50 mL × 3), dried
over MgSO4, and evaporated under reduced pressure. The
residue was purified by silica gel column chromatography using
hexane–AcOEt (10:1 for 3a–d, 10a, and 12b; 7:1 for 3e, 9a,b,
12a, and 12c; 5:1 for 10b and 11, 3:1 for 3f) as eluent.
2-Nitrobenzonitrile 3f. According to the General Procedure
A, the reaction using 2-iodonitrobenzene 1f (125 mg, 0.5 mmol)
gave 3f (49.9 mg, 67%). The crude product was recrystallized
from hexane–acetone to give colorless needles, mp 109–110 ЊC
(lit.,9 108 ЊC); νmax(KBr)/cmϪ1 1340, 1540, and 2225; δH 7.81–
7.87 (2H, m), 7.91–7.96 (1H, m), 8.33–8.39 (1H, m); m/z 148
(Mϩ, 100%) (Found: Mϩ, 148.0281. C7H4N2O2 requires M,
148.0272).
4-Methoxybenzonitrile 3a. According to the General
Procedure A, the reaction using 4-bromoanisole 2a (187 mg, 1.0
mmol) gave 3a (120 mg, 91%). The crude product was recrystal-
lized from hexane–AcOEt to give colorless needles, mp 56–
57 ЊC (lit.,9 58 ЊC); νmax(KBr)/cmϪ1 2210; δH 3.87 (3H, s), 6.96
(2H, d, J 8.24), 7.60 (2H, d, J 8.24); m/z 133 (Mϩ, 100%)
(Found: Mϩ, 133.0537. C8H7NO requires M, 133.0527).
1-(Phenylsulfonyl)indole-2-carbonitrile 9a. According to the
General Procedure B, the reaction using 2-iodo-1-(phenyl-
sulfonyl)indole 4a (383 mg, 1.0 mmol) gave 9a (266.1 mg, 94%).
The crude product was recrystallized from hexane–AcOEt to
give colorless prisms, mp 127–128 ЊC (Found: C, 63.62; H, 3.56;
N, 9.93; S, 11.34. C15H10N2O2S requires C, 63.82; H, 3.57; N,
Methyl 4-cyanobenzoate 3b. According to the General
Procedure A, the reaction using methyl 4-bromobenzoate 2b
J. Chem. Soc., Perkin Trans. 1, 1999, 2323–2326
2325

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9.92; S, 11.36%); νmax(KBr)/cmϪ1 1170, 1310, and 2225; δH 7.36
(2H, t, J 6.87), 7.48–7.65 (5H, m), 8.04 (2H, d, J 7.42), 8.23 (1H,
d, J 8.52); m/z 282 (Mϩ, 45%), and 77 (100) (Found: Mϩ,
282.0446. C15H10N2O2S requires M, 282.0462).
Quinoline-3-carbonitrile 12b. According to the General
Procedure B, the reaction using 3-iodoquinoline 8b (128 mg, 0.5
mmol) gave 12b (69.9 mg, 91%). The crude product was re-
crystallized from hexane–acetone to give colorless prisms, mp
105–107 ЊC (lit.,10 109 ЊC) (Found: C, 77.96; H, 3.99; N, 18.14.
C10H6N2 requires C, 77.91; H, 3.92; N, 18.17%); νmax(KBr)/cmϪ1
2240; δH 7.71 (1H, t, J 8.24), 7.88–7.94 (2H, m), 8.19 (1H, d,
J 9.07), 8.56 (1H, d, J 1.92), 9.06 (1H, d, J 1.92); m/z 154 (Mϩ,
100%) (Found: Mϩ, 154.0533. C10H6N2 requires M, 154.0531).
1-(Phenylsulfonyl)indole-3-carbonitrile 9b. According to the
General Procedure B, the reaction using 3-iodo-1-(phenyl-
sulfonyl)indole 4b (383 mg, 1.0 mmol) gave 9b (278.8 mg, 99%).
The crude product was recrystallized from hexane–AcOEt to
give colorless prisms, mp 151–152 ЊC (Found: C, 63.73; H, 3.58;
N, 9.99; S, 11.37. C15H10N2O2S requires C, 63.82; H, 3.57; N,
9.92; S, 11.36%); νmax(KBr)/cmϪ1 1170, 1380, and 2227; δH 7.37–
7.58 (4H, m), 7.60–7.73 (2H, m), 7.95–8.03 (3H, m), 8.12 (1H,
s); m/z 282 (Mϩ, 37%), and 77 (100) (Found: Mϩ, 282.0453).
2-Methylquinoline-4-carbonitrile 12c. According to the
General Procedure B, the reaction using 4-iodo-2-methyl-
quinoline 8c (135 mg, 0.5 mmol) gave 12c (81 mg, 96%). The
crude product was recrystallized from hexane–acetone to give
colorless needles, mp 102–104 ЊC (Found: C, 78.46; H, 4.72; N,
16.43. C11H8N2 requires C, 78.55; H, 4.79; N, 16.66%);
νmax(KBr)/cmϪ1 2240; δH 2.81 (3H, s), 7.64 (1H, s), 7.70 (1H, dt,
J 1.37, 8.24), 7.83 (1H, dt, J 1.37, 8.24), 8.12 (1H, d, J 8.24),
8.16 (1H, d, J 8.24); m/z 168 (Mϩ, 100%) (Found: Mϩ, 168.0691.
C11H8N2 requires M, 168.0687).
1-(Phenylsulfonyl)pyrrole-2-carbonitrile 10a. According to
the General Procedure B, the reaction using 2-iodo-1-(phenyl-
sulfonyl)pyrrole 5a (117 mg, 0.35 mmol) gave 10a (78.7 mg,
97%). The crude product was recrystallized from hexane–
acetone to give needles, mp 83–85 ЊC (Found: C, 56.91; H, 3.54;
N, 12.06; S, 13.72. C11H8N2O2S requires C, 56.89; H, 3.47; N,
12.06; S, 13.80%); νmax(KBr)/cmϪ1 1180, 1380, and 2240; δH 6.34
(1H, t, J 3.30), 6.98 (1H, dd, J 1.65, 3.85), 7.50 (1H, dd, J 1.65,
3.30), 7.57–7.63 (2H, m), 7.68–7.74 (1H, m), 8.05–8.09 (2H, m);
m/z 232 (Mϩ, 37%) and 77 (100) (Found: Mϩ, 232.0322.
C11H8N2O2S requires M, 232.0306).
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3,5-Dimethyl-1-(phenylsulfonyl)pyrazole-4-carbonitrile
11.
( f ) N. Sato and M. Suzuiki, J. Heterocycl. Chem., 1987, 24, 1371;
(g) K. Takagi and Y. Sakakibara, Chem. Lett., 1989, 1957; (h) K.
Takagi, K. Sasaki and Y. Sakakibara, Bull. Chem. Soc. Jpn., 1991,
64, 1118; (i) G. A. Kraus and H. Maeda, Tetrahedron Lett., 1994, 35,
9189.
According to the General Procedure B, the reaction using
4-iodo-3,5-dimethy-1-(phenylsulfonyl)pyrazole 6 (362 mg, 1.0
mmol) gave 11 (235.6 mg, 90%). The crude product was
recrystallized from hexane–acetone to give colorless needles,
mp 106–108 ЊC (Found: C, 55.19; H, 4.29; N, 16.03; S, 12.26.
C12H11N3O2S requires C, 55.16; H, 4.24; N, 16.08; S, 12.27%);
νmax(KBr)/cmϪ1 1200, 1400, and 2250; δH 2.33 (3H, s), 2.70 (3H,
s), 7.58–7.63 (2H, m), 7.70–7.75 (1H, m), 8.01–8.04 (2H, m);
m/z 261 (Mϩ, 11%), and 77 (100) (Found: Mϩ, 261.0602.
C12H11N3O2S requires M, 261.0571).
5 J. R. Dalton and S. L. Regen, J. Org. Chem., 1979, 44, 4443.
6 N. Chatani and T. Hanafusa, J. Org. Chem., 1986, 51, 4714.
7 (a) D. M. Tschaen, R. Desmond, A. O. King, M. C. Fortin, B. Pipik,
S. King and T. R. Verhoeven, Synth. Commun., 1994, 24, 887;
(b) H. G. Selnick, G. R. Smith and A. J. Tebben, Synth. Commun.,
1995, 25, 3255; (c) H. Kubota and K. C. Rice, Tetrahedron Lett.,
1998, 39, 2907; (d) T. Okano, J. Kiji and Y. Toyooka, Chem. Lett.,
1998, 425.
8 B. A. Anderson, E. C. Bell, F. O. Ginah, N. K. Harn, L. M. Pagh
and J. P. Wepsiec, J. Org. Chem., 1998, 63, 8224.
Quinoline-2-carbonitrile 12a. According to the General
Procedure B, the reaction using 2-iodoquinoline 8a (255 mg, 1.0
mmol) gave 12a (139.5 mg, 90%). The crude product was
recrystallized from hexane–AcOEt to give colorless plates, mp
92–94 ЊC (lit.,10 94 ЊC) (Found: C, 77.91; H, 3.90; N, 18.15.
C10H6N2 requires C, 77.91; H, 3.92; N, 18.17%); νmax(KBr)/cmϪ1
2250; δH 7.69–7.75 (2H, m), 7.86 (1H, dt, J 1.37, 6.87), 7.91
(1H, d, J 7.97), 8.19 (1H, d, J 8.52), 8.32 (1H, d, J 8.52);
m/z 154 (Mϩ, 100%) (Found: Mϩ, 154.0544. C10H6N2 requires
M, 154.0531).
9 The Aldrich Library of 13C and 1H FT NMR Spectra, ed. C. J.
Pouchert and J. Behnke, Aldrich Chemical Co. Inc., New York,
1993, vol. 2, pp. 1510, 1511, 1519, 1522, 1523.
10 The Aldrich Library of 13C and 1H FT NMR Spectra, ed. C. J.
Pouchert and J. Behnke, Aldrich Chemical Co. Inc., New York,
1993, vol. 3, p. 452.
Paper 9/03345I
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J. Chem. Soc., Perkin Trans. 1, 1999, 2323–2326