Syntheses of cyanoselenoamides and diselenoamides: Conversion into selenazoles and selenazines

Article abstract of DOI:10.1002/hc.10111

Reactions of dicyano compounds with a potassium selenocarboxylate afforded the corresponding cyanoselenoamides and diselenoamides in good yields of experimentally determined ratios. The obtained cyanosdenoamides were allowed to react with potassium seleno

Full text of DOI:10.1002/hc.10111

Heteroatom Chemistry
Volume 14, Number 1, 2003
Syntheses of Cyanoselenoamides and
Diselenoamides: Conversion into Selenazoles
and Selenazines
Mamoru Koketsu, Yuichi Takenaka, and Hideharu Ishihara
Department of Chemistry, Faculty of Engineering, Gifu University, Gifu 501-1193, Japan
Received 6 February 2002; revised 7 April 2002
amides and the syntheses of selenazoles and selena-
ABSTRACT: Reactions of dicyano compounds with
zines, using the cyanoselenoamides and dise-
a potassium selenocarboxylate afforded the corre-
lenoamides.
sponding cyanoselenoamides and diselenoamides in
good yields of experimentally determined ratios. The
obtained cyanoselenoamides were allowed to react
RESULTS AND DISCUSSION
with potassium selenocarboxylate, again to afford
the corresponding diselenoamides in higher yields.
The cyanoselenoamides and diselenoamides were in-
vestigated as substrates for preparations of selena-
Optimal conditions for the preparation of cyanose-
lenoamides 3 and diselenoamides 4 from the corre-
sponding dicyano compounds 1 were determined by
trial and error. The best conditions for the synthe-
sis of 4 were found to be as shown in Scheme 1.
The reactions at room temperature and −30◦C gave
3 of higher yield and 4 of lower yield than under the
conditions shown in Scheme 1. Results of reactions
using various dicyano compounds 1 are summarized
in Table 1. The reaction of 1c gave the corresponding
diselenoamide 4c in very low yield because of steric
hindrance. The reactions of 1d and 1e gave neither
the cyanoselenoamides 3 nor the diselenoamides 4.
Isolated 3a was allowed to react with 2 again
under similar conditions for the preparation of 4a
(Table 2), the best result being obtained by the
use 2 equiv. of 2 and a reaction of 3 h. 4a–c
were synthesized using the best conditions (Table 2)
(Scheme 2).
Reactions of 3b and 4b with four kinds of
carbonyl compounds, i.e., an ꢀ-haloacyl halide, a
bisacyl chloride, an ꢀ-halo ketone, and an ꢀ,ꢁ-
unsaturated ketone, were attempted for syntheses of
the selenazole and selenazine, respectively, accord-
ing to the previously reported procedures with mono
primary selenoamide (Scheme 3) [2a,c,d,4]. When
3b reacted with chloroacetyl chloride, malonyl
chloride, and phenacyl bromide, the corresponding
ꢀ
C
zoles and selenazines.
2003 Wiley Periodicals, Inc.
Heteroatom Chem 14:106–110, 2003; Published online
in Wiley InterScience (www.interscience.wiley.com). DOI
10.1002/hc.10111
INTRODUCTION
Many selenocarbonyl compounds have been pre-
pared and recent reviews detail these studies [1].
Selenoamides have been used as precursors for the
synthesis of both selenium- and nitrogen-containing
heterocyclic compounds [2]. Generally, the prepara-
tion of primary selenoamides has been carried out
by the reaction of nitriles with appropriate selenat-
ing reagents [3]. Diselenoamides are also important
for the synthesis of both selenium- and nitrogen-
containing heterocyclic compounds. However, there
currently exists only one practical synthesis of dise-
lenoamides [4]. In the present study, we investigated
the preparation of cyanoselenoamides and diseleno-
Correspondence to: Mamoru Koketsu; e-mail: koketsu@cc.gifu-
u.ac.jp.
c
ꢀ
2003 Wiley Periodicals, Inc.
106

Syntheses of Cyanoselenoamides and Diselenoamides: Conversion into Selenazoles and Selenazines 107
SCHEME 1
TABLE 2 Investigations of Optimal Conditions for Synthesis
of Diselenoamide 4a from Cyanoselenoamide 3a
selenazol-4-one (5), selenazin-4-one (6), and selena-
zole (7), respectively, were formed. However, reac-
tion with methyl vinyl ketone gave no identifiable
products other than the starting material and com-
plicated mixtures of the reactions of 4b with the
carbonyl compounds, only that with phenacyl bro-
mide gave the corresponding diselenazole 8. The
other reactions of 4b afforded no identifiable prod-
ucts owing to the instability and insolubility of 4b in
organic solvents. Methanol and ethanol, which dis-
solve 4b could not be used in the reaction with an
acyl chloride.
2 (equiv.) Time (h) Recovery of 3a (%) Yield of 4a (%)
1
1.5
2
3
2
3
3
3
3
1
5
66
42
17
19
21
24
27
55
79
78
74
72
2
TABLE
1 Syntheses of Cyanoselenoamides and Di-
selenoamides
1 or 3
3
4
SCHEME 2
SCHEME 3
EXPERIMENTAL
General
Melting points were determined by use of a
Yanagimoto micromelting point apparatus and are

108 Koketsu, Takenaka, and Ishihara
1
cm−1; H NMR (400 MHz, DMSO-d6): δ 7.43 (t, J =
uncorrected. IR spectra were measured on a Perkin-
1
Elmer 1600 spectrometer. H, 13C, and 77Se NMR
7.8 Hz, 1H, Ar), 7.96 (dd, J = 2.0, 7.8 Hz, 2H, Ar),
8.27 (s, 1H, Ar), 10.29 (br s, 2H, NH), 10.90 (br s, 2H,
NH); 13C NMR (100 MHz, DMSO-d6): δ 125.8, 127.7,
129.6, 142.4, 203.4; 77Se NMR (76 MHz, DMSO-d6):
δ 599.7; MS (CI) m/z = 293 [M+ + 1].
spectra were recorded on a JEOL-JNM-ꢀ400 spec-
trometer. Mass spectra were obtained on a Shimadzu
9020-DF mass spectrometer. Tetrahydrofuran was
distilled from sodium-benzophenone and immedi-
ately used. The 77Se chemical shifts are expressed
in ppm, deshielded, with respect to Me2Se in
CDCl3.
3-Cyano-2-methylbenzoselenoamide (3c). Yel-
low solid; mp 145.0–146.0◦C; IR (KBr) 3319, 3128,
2226, 1638 cm−1; H NMR (400 MHz, acetone-d6): δ
1
Typical Procedure for 4-Cyanobenzoselenoamide
(3a) and 1,4-Benzenediselenocarboxamide (4a).
Terephtalonitrile (0.64 g, 5.0 mmol) and boron
trifluoride ether complex (3.62 g, 12 mmol) were
added to the THF solution (30 ml) of potassium
4-methylselenobenzoate (2.37 g, 10 mmol) under
an argon atmosphere at 0◦C. The reaction mixture
was stirred at 0◦C for 3 h. The mixture was ex-
tracted with ethyl acetate and washed with water.
The organic layer was dried over sodium sulfate
and evaporated to dryness. The residue was pu-
rified by flash chromatography on silica gel with
dichloromethane/diethyl ether (10:1) as eluent to
give 3a (0.38 g; yield 36%) as a white powder and
4a (0.35 g; yield 24%) of 4-Cyanobenzoselenoamide
(3a), an orange solid; mp 151.2–152.6◦C; IR (KBr)
2.56 (s, 3H, CH3), 7.39 (t, J = 7.8 Hz, 1H, Ar), 7.59
(d, J = 7.8 Hz, 1H, Ar), 7.68 (d, J = 7.8 Hz, 1H,
Ar), 9.70 (br s, 1H, NH), 10.33 (br s, 1H, NH); 13C
NMR (100 MHz, acetone-d6): δ 17.9, 114.2, 118.0,
127.1, 130.6, 133.2, 135.4, 148.6, 208.0; 77Se NMR
(76 MHz, acetone-d6): δ 720.6; MS (CI) m/z = 225
[M+ + 1]; Anal calcd for C9H8N2Se: C, 48.44; H, 3.61;
N, 12.55. Found: C, 48.78; H, 3.88; N, 12.51.
2-Methyl-1,3-benzenediselenocarboxamide (4c).
Yellow solid; mp 164.2–165.6◦C; IR (KBr) 3195,
1
3018, 1648 cm−1; H NMR (400 MHz, DMSO-d6): δ
2.27 (s, 3H, CH3), 7.12–7.20 (m, 3H, Ar), 10.36 (br s,
2H, NH), 10.99 (br s, 2H, NH); 13C NMR (100 MHz,
DMSO-d6): δ 15.6, 124.0, 124.5, 125.0, 146.7, 206.6;
77Se NMR (76 MHz, DMSO-d6): δ 642.1; MS (CI)
m/z = 307 [M+ + 1].
1
3348, 3181, 2240, 1624 cm−1; H NMR (400 MHz,
acetone-d6): δ 7.79 (d, J = 8.8 Hz, 2H, Ar), 8.07
(d, J = 8.8 Hz, 2H, Ar), 9.78 (br s, 1H, NH), 10.26
(br s, 1H, NH); 13C NMR (100 MHz, acetone-d6): δ
114.7, 118.9, 128.4, 132.7, 147.4, 205.6; 77Se NMR
(76 MHz, acetone-d6): δ 707.1; MS (CI) m/z = 211
[M+ + 1]; Anal calcd for C8H6N2Se: C, 45.95; H,
2.89; N, 13.40. Found: C, 45.98; H, 2.99; N, 13.34.
1,4-Benzenediselenocarboxamide (4a) Brown solid;
mp 185.0–187.0◦C; IR (KBr) 3266, 3111, 1630 cm−1;
1H NMR (400 MHz, DMSO-d6): δ 7.84 (s, 4H, Ar),
10.32 (br s, 2H, NH), 10.94 (br s, 2H, NH); 13C
NMR (100 MHz, DMSO-d6): δ 126.8, 144.0, 203.0;
77Se NMR (76 MHz, DMSO-d6): δ 611.8; MS (CI)
m/z = 293 [M+ + 1].
1,4-Butanediselenoamide (4f). Brown solid; mp
96.6–98.0◦C; IR (KBr) 3262, 3110, 1635 cm−1; 1H
NMR (400 MHz, DMSO-d6): δ 2.87 (s, 4H, CH2), 10.02
(br s, 2H, NH), 10.36 (br s, 2H, NH); 13C NMR (100
MHz, DMSO-d6): δ 46.6, 210.1; 77Se NMR (76 MHz,
DMSO-d6): δ 493.6; MS (CI) m/z = 245 [M+ + 1].
4-Cyanobutaneselenoamide (3g). Red liquid; IR
1
(neat) 3299, 3178, 2249, 1635 cm−1; H NMR (400
MHz, acetone-d6): δ 2.16 (quint, J = 7.2 Hz, 2H,
CH2), 2.59 (t, J = 7.2 Hz, 2H, CH2), 2.76 (t, J =
7.2 Hz, 2H, CH2), 9.48 (br s, 1H, NH), 9.65 (br s,
1H, NH); 13C NMR (100 MHz, acetone-d6): δ 16.2,
26.1, 46.9, 120.2, 213.6; 77Se NMR (76 MHz, acetone-
d6): δ 550.4; MS (CI) m/z = 177 [M+ + 1]; Anal calcd
for C5H8N2Se: C, 34.30; H, 4.61; N, 16.00. Found: C,
34.67; H, 4.85; N, 15.91.
3-Cyanobenzeselenocarboxamide (3b). A red
solid; mp 132.4–133.6◦C; IR (KBr) 3352, 3123, 2234,
1
1649 cm−1; H NMR (400 MHz, acetone-d6): δ 7.65
(t, J = 7.8 Hz, 1H, Ar), 7.94 (d, J = 7.8 Hz, 1H, Ar),
8.26–8.31 (m, 2H, Ar), 9.79 (br s, 1H, NH), 10.25
(br s, 1H, NH); 13C NMR (100 MHz, acetone-d6): δ
112.9, 118.6, 130.2, 131.2, 132.4, 134.9, 144.8, 204.9;
77Se NMR (76 MHz, acetone-d6): δ 683.2; MS (EI)
m/z = 210 [M+]; Anal calcd for C8H6N2Se: C, 45.95;
H, 2.89; N, 13.40. Found: C, 46.11; H, 3.04; N, 13.25.
1,5-Pentanediselenoamide (4g). Yellow solid;
mp 94.2–95.8◦C; IR (KBr) 3272, 3108, 1636 cm−1; 1H
NMR (400 MHz, DMSO-d6): δ 2.04 (quint, J = 7.6
Hz, 2H, CH2), 2.53 (t, J = 7.6 Hz, 4H, CH2), 9.95 (br
s, 2H, NH), 10.29 (br s, 2H, NH); 13C NMR (100 MHz,
DMSO-d6): δ 28.7, 46.8, 211.3; 77Se NMR (76 MHz,
DMSO-d6): δ 505.5; MS (CI) m/z = 259 [M+ + 1].
1,3-Benzenediselenocarboxamide (4b). Orange
solid; mp 155.6–156.8◦C; IR (KBr) 3267, 3134, 1633

Syntheses of Cyanoselenoamides and Diselenoamides: Conversion into Selenazoles and Selenazines 109
5-Cyanopentaneselenoamide (3h). Yellow liq-
uid; IR (neat) 3299, 3172, 2248, 1635 cm−1; 1H NMR
(400 MHz, acetone-d6): δ 1.72 (quint, J = 7.8 Hz,
2H, CH2), 1.94 (quint, J = 7.8 Hz, 2H, CH2), 2.52 (t,
J = 7.8 Hz, 2H, CH2), 2.74 (t, J = 7.8 Hz, 2H, CH2),
9.40 (br s, 1H, NH), 9.59 (br s, 1H, NH); 13C NMR
(100 MHz, acetone-d6): δ 17.0, 25.2, 29.3, 48.4, 120.6,
214.9; 77Se NMR (76 MHz, acetone-d6): δ 549.6; MS
(CI) m/z = 191 [M+ + 1]; Anal calcd for C6H10N2Se:
C, 38.11; H, 5.33; N, 14.81. Found: C, 38.24; H, 5.38;
N, 14.81.
4-Oxa-1,7-heptanediselenoamide
(4j). Yellow
solid; mp 116.0–117.4◦C; IR (KBr) 3330, 3090, 1648
cm−1; 1H NMR (400 MHz, DMSO-d6): δ 2.75 (t,
J = 6.5 Hz, 4H, CH2), 3.73 (t, J = 6.5 Hz, 4H, CH2),
10.00 (br s, 2H, NH), 10.37 (br s, 2H, NH); 13C NMR
(100 MHz, DMSO-d6): δ 47.8, 69.1, 208.7; 77Se NMR
(76 MHz, DMSO-d6): δ 500.9; MS (CI) m/z = 289
[M+ + 1].
2-(3-Cyanophenyl)-1,3-selenazol-4-one (5). Yel-
low solid; mp 167.2–169.0◦C; IR (KBr) 2230, 1714,
1
1603 cm−1; H NMR (400 MHz, DMSO-d6): δ 4.55
(s, 2H, CH2), 7.82 (t, J = 7.8 Hz, 1H, Ar), 8.23 (d,
J = 7.8 Hz, 1H, Ar), 8.35 (d, J = 7.8 Hz, 1H, Ar),
8.45 (s, 1H, Ar); 13C NMR (100 MHz, DMSO-d6): δ
36.5, 112.8, 117.6, 130.8, 131.9, 132.8, 135.0, 138.0,
192.7, 194.5; 77Se NMR (76 MHz, DMSO-d6): δ 355.5;
MS (EI) m/z = 250 [M+]; Anal calcd for C10H6N2OSe:
C, 48.21; H, 2.43; N, 11.24. Found: C, 48.25; H, 2.44;
N, 11.31.
1,6-Hexanediselenoamide (4h). Yellow solid;
mp 145.2–146.4◦C; IR (KBr) 3285, 3109, 1643 cm−1;
1H NMR (400 MHz, DMSO-d6): δ 1.62 (m, 4H, CH2),
2.49 (m, 4H, CH2), 9.90 (br s, 2H, NH), 10.22 (br
s, 2H, NH); 13C NMR (100 MHz, DMSO-d6): δ 28.2,
47.8, 211.9; 77Se NMR (76 MHz, DMSO-d6): δ 497.8;
MS (CI) m/z = 273 [M+ + 1].
6-Cyanohexaneselenoamide (3i). Yellow solid;
mp 44.0–45.2◦C; IR (KBr) 3298, 3104, 2248, 1637
cm−1; 1H NMR (400 MHz, acetone-d6): δ 1.48 (quint,
J = 7.6 Hz, 2H, CH2), 1.65 (quint, J = 7.6 Hz, 2H,
CH2), 1.82 (quint, J = 7.6 Hz, 2H, CH2), 2.45 (t,
J = 7.6 Hz, 2H, CH2), 2.68 (t, J = 7.6 Hz, 2H, CH2),
9.35 (br s, 1H, NH), 9.52 (br s, 1H, NH); 13C NMR (100
MHz, acetone-d6): δ 17.1, 25.9, 28.4, 29.5, 49.1, 120.7,
215.5; 77Se NMR (76 MHz, acetone-d6): δ 544.1; MS
(CI) m/z 205 [M+ + 1]; Anal calcd for C7H12N2Se: C,
41.39; H, 5.95; N, 13.79. Found: C, 41.41; H, 6.02; N,
13.82.
2-(3-Cyanophenyl)-6-hydroxy-1,3-selenazin-4-one
(6). Yellow solid; mp 173.0–174.2◦C; IR (KBr) 3423,
1
2242, 1655 cm−1; H NMR (400 MHz, DMSO-d6): δ
5.24 (s, 1H, CH), 7.80 (t, J = 7.8 Hz, 1H, Ar), 8.16
(d, J = 7.8 Hz, 1H, Ar), 8.28 (d, J = 7.8 Hz, 1H, Ar),
8.40 (s, 1H, Ar), 12.60 (br s, 1H, OH); 13C NMR (100
MHz, DMSO-d6): δ 89.1, 112.6, 117.8, 130.7, 131.9,
136.4, 139.1, 171.2, 178.5, 181.8; 77Se NMR (76
MHz, DMSO-d6): δ 692.6; MS (CI) m/z 279 [M+ + 1];
Anal calcd for C11H6N2O2Se: C, 47.67; H, 2.18; N,
10.11. Found: C, 47.74; H, 2.23; N, 10.22.
2-(3-Cyanophenyl)-4-phenyl-1,3-selenazole (7).
White solid; mp 104.4–106.0◦C; IR (KBr) 2229, 1601
cm−1; 1H NMR (400 MHz, CDCl3): δ 7.37 (tt, J = 1.6,
7.6 Hz, 1H, Ar), 7.45 (t, J = 7.6 Hz, 2H, Ar), 7.54 (t,
J = 7.6 Hz, 1H, Ar), 7.70 (dt, J = 1.6, 7.6 Hz, 1H,
Ar), 7.98 (d, J = 7.6 Hz, 2H, Ar), 8.15 (dt, J = 1.6,
7.6 Hz, 1H, Ar), 8.16 (s, 1H, CH), 8.29 (t, J = 1.6 Hz,
1H, Ar); 13C NMR (100 MHz, CDCl3): δ 113.3, 118.2,
119.6, 126.7, 128.2, 128.8, 129.8, 130.2, 131.0, 133.1,
134.8, 137.4, 157.4, 170.8; 77Se NMR (76 MHz,
CDCl3): δ 724.1; MS (CI) m/z 311 = [M+ + 1]; Anal
calcd for C16H10N2Se: C, 62.15; H, 3.26; N, 9.06.
Found: C, 64.23; H, 3.31; N, 9.00.
1,7-Heptanediselenoamide (4i). Yellow solid;
mp 129.0–130.6◦C; IR (KBr) 3280, 3116, 1631 cm−1;
1H NMR (400 MHz, DMSO-d6): δ 1.27 (quint, J = 7.6
Hz, 2H, CH2), 1.67 (quint, J = 7.6 Hz, 4H, CH2), 2.53
(t, J = 7.6 Hz, 4H, CH2), 9.94 (br s, 2H, NH), 10.27
(br s, 2H, NH); 13C NMR (100 MHz, DMSO-d6): δ 27.2,
28.7, 47.9, 212.1; 77Se NMR (76 MHz, DMSO-d6): δ
497.3; MS (CI) m/z = 287 [M+ + 1].
6-Cyano-4-oxaheptaneselenoamide (3j). Yellow
1
liquid; IR (neat) 3303, 3188, 2253, 1631 cm−1; H
NMR (400 MHz, acetone-d6): δ 2.70 (t, J = 6.1 Hz,
2H, CH2), 2.89 (t, J = 6.1 Hz, 2H, CH2), 3.69 (t,
J = 6.1 Hz, 2H, CH2), 3.88 (t, J = 6.1 Hz, 2H, CH2),
9.36 (br s, 1H, NH), 9.60 (br s, 1H, NH); 13C NMR
(100 MHz, acetone-d6): δ 19.1, 49.3, 66.5, 70.4, 119.2,
212.1; 77Se NMR (76 MHz, acetone-d6): δ 549.4; MS
(CI) m/z = 207 [M+ + 1]; Anal calcd for C6H10N2OSe:
C, 35.13; H, 4.91; N, 13.66. Found: C, 35.41; H, 4.99;
N, 13.64.
1,3-Bis(4-phenyl-1,3-selenazol-2-yl)benzene (8).
White solid; mp 181.2–183.2◦C; IR (KBr) 1599 cm−1;
1H NMR (400 MHz, CDCl3): δ 7.36 (t, J = 7.8 Hz, 2H,
Ar), 7.46 (t, J = 7.8 Hz, 4H, Ar), 7.52 (t, J = 7.8 Hz,
1H, Ar), 8.03 (dd, J = 1.6, 7.8 Hz, 4H, Ar), 8.07 (dd,
J = 1.6, 7.8 Hz, 2H, Ar), 8.14 (s, 2H, CH), 8.53 (t,
J = 1.6 Hz, 1H, Ar); 13C NMR (100 MHz, CDCl3): δ
118.9, 125.5, 126.8, 128.0, 128.6, 128.7, 129.6, 135.3,

110 Koketsu, Takenaka, and Ishihara
137.2, 157.1, 172.9; 77Se NMR (76 MHz, CDCl3): δ
719.1; MS (CI) m/z = 493 [M+ + 1]; Anal calcd for
C24H16N2Se2: C, 58.79; H, 3.29; N, 5.71. Found: C,
58.75; H, 3.41; N, 5.74.
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