Synthesis of 4-Aryl-2-imino-2H-selenazolines by a reaction of α α-(selenocyanato)acetophenones with anilines

Article abstract of DOI:10.1080/10426500600892685

4-Aryl-2-imino-2H-selenazolines have been prepared by a reaction of α-(selenocyanato)acetophenones with anilines.

Full text of DOI:10.1080/10426500600892685

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Phosphorus, Sulfur, and Silicon
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Synthesis of 4-Aryl-2-
imino-2H-selenazolines
by a Reaction of α α-
(Selenocyanato)acetophenones
With Anilines
Anja Bodtke a , Madeleine Kandt a , Wolf-Diethard
Pfeiffer a & Peter Langer b c
a Institut für Biochemie, Universität Greifswald ,
Greifswald, Germany
b Institut für Chemie, Universität Rostock , Rostock,
Germany
c Leibniz-Institut für Katalyse e. V. an der
Universität Rostock , Rostock, Germany
Published online: 01 Feb 2007.
To cite this article: Anja Bodtke , Madeleine Kandt , Wolf-Diethard Pfeiffer & Peter
Langer (2007) Synthesis of 4-Aryl-2-imino-2H-selenazolines by a Reaction of α α-
(Selenocyanato)acetophenones With Anilines, Phosphorus, Sulfur, and Silicon and the
Related Elements, 182:1, 209-217, DOI: 10.1080/10426500600892685
To link to this article: http://dx.doi.org/10.1080/10426500600892685
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Phosphorus, Sulfur, and Silicon, 182:209–217, 2007
Copyright © Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500600892685
Synthesis of 4-Aryl-2-imino-2H-selenazolines by a
Reaction of α-(Selenocyanato)acetophenones With
Anilines
Anja Bodtke
Madeleine Kandt
Wolf-Diethard Pfeiffer
Institut fu¨r Biochemie, Universita¨t Greifswald, Greifswald, Germany
Peter Langer
Institut fu¨r Chemie, Universita¨t Rostock, Rostock, Germany, and
Leibniz-Institut fu¨r Katalyse e. V. an der Universita¨t Rostock,
Rostock, Germany
4-Aryl-2-imino-2H-selenazolines have been prepared by
(selenocyanato)acetophenones with anilines.
a reaction of α-
Keywords Cyclization; heterocycles; selenium
Selenium represents an essential element for higher organisms.1
As selenium-containing enzymes—i.e., Glutathioneperoxidase and 5ꢀ-
Deiodase type 1—are very important for the organism, various diseases
can result from selenium deficiency.2,3 As a consequence, selenium-
containing heterocycles are of considerable biochemical and pharma-
cological relevance. In this context, the antitumor and antiviral agent
C-glycosyl selenazole selenazofurin represents a prominent example.4
Selenium heterocycles are often less stable than the corresponding
sulfur analogues. In addition, methods and conditions available for
the synthesis of sulfur compounds often can not be applied to sele-
nium. Therefore, the development of new methods for the synthesis of
small selenium-containing building blocks is of considerable current
interest.5,6
Received May 30, 2006; accepted June 13, 2006.
Financial support from the state of Mecklenburg-Vorpommern (scholarship for
A. B. and Landesforschungsschwerpunkt “Neue Wirkstoffe und Screeningverfahren”) is
gratefully acknowledged.
Address correspondence to Peter Langer, Institut fu¨r Chemie, Universita¨t Rostock,
Albert-Einstein Str. 3a, Rostock, 18059 Germany. E-mail: peter.langer@uni-rostock.de
209

210
A. Bodtke et al.
TABLE I The Synthesis of 2a–d
2
R1
R2
Yield (%)a
a
b
c
H
Cl
Br
H
H
H
H
59
33
41
46
d
Ph
aYields of isolated products.
α-(selenocyanato)ketones represent useful synthetic build-
ing blocks for the synthesis of selenium heterocycles.7 1,3,4-
selenadiazoles have been prepared by [3 + 2] cycloaddition of
α-(selenocyanato)acetophenones with diazonium salts.8 Aliphatic
selenium heterocycles are available by [4 + 2] cycloaddition of
α-(selenocyanato)ketones with 1,3-butadienes.9 In addition, sodium-
hydride mediated cyclizations of α-(selenocyanato)acetophenones
that give five-membered selenium heterocycles have been
reported.10 Herein, we report the synthesis of 4-aryl-2-imino-2H-
selenazolines that are, to the best of our knowledge, the first
reactions of α-(selenocyanato)acetophenones with amines.11 α-
(selenocyanato)acetophenones are readily available by a reaction of
phenacylbromides with potassium selenocyanate (KSeCN).9b,10,12
The known α-(selenocyanato)acetophenones 2a–d were prepared by
a reaction of phenacylbromides 1a–d with KSeCN (Scheme 1, Table I).
The acid-mediated cyclization of α-(selenocyanato)acetophenones 2a–
d with anilines 3a–c afforded 4-aryl-2-imino-2H-selenazolines 4a–g
(Scheme 2, Table II). The formation of the latter can be explained
by an acid-catalyzed attack of the amine onto the selenocyanato
group, an attack of the imino group thus formed onto the carbonyl
group, and the subsequent elimination of water. The reaction of α-
(selenocyanato)acetophenone 2b with hydroxylamine hydrochloride af-
forded the selenazoline 4h (Scheme 3). During optimization of reaction
conditions, employment of amines in the form of their hydrochlorides
proved to be important. In addition, the reaction time and the solvent
played an important role. The relatively low yields can be explained
by the unstable nature of the products and decomposition during the
reaction.
O
KSeCN
O
R1
R1
Br
acetone
4 h, reflux
SeCN
R2
1a–d
R2
2a–d
SCHEME 1 The cyclization of α-(selenocyanato)acetophenones.

Synthesis of 4-Aryl-2-imino-2H-selenazolines
211
O
R1
R4
R5
SeCN
_
_
R2
2a–d
R3
Cl
EtOH
NH2+
R5
R3
+
N
5 h, reflux
R1
Se
_
R4
NH +
Cl
3
H2O
R2
4a–g
R1-R5: see Table II
3a–c
H
O N
NH
R1
Se
R2
R5
R3
R4
A
SCHEME 2 The cyclization of α-(selenocyanato)acetophenones with phenacyl
bromides.
In summary, 4-aryl-2-imino-2H-selenazolines have been prepared by
a reaction of α-(selenocyanato)acetophenones with anilines.
EXPERIMENTAL
General Comments
All solvents were dried by standard methods, and all reactions were car-
ried out under an inert atmosphere. For 1H and 13C NMR, the deuter-
ated solvents indicated were used. Mass spectrometric data (MS) were
TABLE II The Synthesis of 4a–g
4
R1
R2
R3
R4
R5
Yield (%)a
a
b
c
d
e
f
H
H
H
H
H
H
H
H
Cl
H
H
Cl
H
H
Cl
H
H
Cl
H
Cl
Cl
H
Cl
H
H
Cl
H
H
27
21
13
15
Cl
Cl
Br
Br
H
2
b
H
Ph
g
10
aYields of isolated products.
bProduct contains 4-chloroaniline hydrochloride.

212
A. Bodtke et al.
_
O
Cl
Cl
HO
NH2+
SeCN
N
EtOH
2b
Cl
Se
5 h, reflux
_
+
+
HO NH3
Cl
_
H2O
4h (17%)
3d
SCHEME 3 The cyclization of α-(selenocyanato)acetophenones with phenacyl
bromides.
obtained by electron ionization (70 eV), chemical ionization (CI, H2O),
or electrospray ionization (ESI). For preparative scale chromatography,
silica gel (60–200 mesh) was used. Melting points are uncorrected.
Synthesis of Phenacyl Selenocyanates 2a–d
The synthesis of 2a–d by a reaction of potassium selenocyanate with
phenacyl bromides has been previously reported.7−12
Phenacyl Selenocyanate (2a)
A mixture of potassium selenocyanate (2.88 g, 20.0 mmol) and phenacyl
bromide (3.96 g, 20.0 mmol) in aceton (30 mL) was refluxed for 4 h. The
hot mixture was filtrated, the solution concentrated in vacuo, and the
resulting solid was isolated by filtration and recrystallization (EtOH).
Yield: 2.63 g (59%), yellow prisms, m.p. 121◦C (ethanol). IR (KBr):
ν˜ = 3002, 2945 (w), 2155 (m), 1666 (s), 1594, 1578 (m), 1449, 1374 (s),
1324, 1310, 1287 (m), 1266, 1195, 996, 755, 688 (s) cm−1 1H NMR
.
(DMSO-d6, 300 MHz): δ = 4.94 (s, 2 H, CH2), 7.51–7.71 (m, 3 H, Ar),
7.94–7.98 (m, 2 H, Ar). 13C NMR (DMSO-d6, 75 MHz): δ = 35.5 (CH2),
103.8 (C), 128.8, 128.9 (CH), 129.2, 134.1, 134.2, 194.6 (C). MS (EI, 70
eV): m/z (%) = 225 (3, [M+H]+ (80Se)), 139 (4), 105 (100, [C6H5CO]+),
91 (8), 77 (35, [C6H5]+), 51 (14). Anal. calcd. for C9H7NOSe (224.12): C,
48.23; H, 3.15; N, 6.25. Found: C, 48.42; H, 3.65; N, 6.41.
4-Chlorophenacyl Selenocyanate (2b)
Starting with potassium selenocyanate (2.88 g, 20.0 mmol) and 4-
chlorophenacyl bromide (4.64 g, 20.0 mmol) in acetone (40 mL), product
2b was isolated by filtration and recrystallization (EtOH). Yield: 1.72 g
(33%), orange needles, m.p. 137◦C (ethanol). IR (KBr): ν˜ = 2989, 2935
(w), 2154 (m), 1659, 1590 (s), 1571 (m), 1490, 1405, 1386 (w), 1313 (m),

Synthesis of 4-Aryl-2-imino-2H-selenazolines
213
1
1294, 1181, 1094 (s), 1015 (w), 999, 819 (s) cm−1. H NMR (DMSO-
d6, 300 MHz): δ = 4.88 (s, 2 H, CH2), 7.49–7.54 (m, 2 H, Ar), 7.88–7.92
(m, 2 H, Ar). 13C NMR (DMSO-d6, 75 MHz): δ = 35.0 (CH2), 103.8 (C),
129.0, 130.7 (CH), 132.9, 139.1, 193.9 (C). MS (EI, 70 eV): m/z (%) = 259
(4, [M+H]+ (80Se)), 139 (100), 110 (32). Anal. calcd. for C9H6ClNOSe
(258.56): C, 41.81; H, 2.34; N, 5.42. Found: C, 43.02; H, 2.54; N, 5.60.
4-Bromophenacyl Selenocyanate (2c)
Starting with potassium selenocyanate (2.88 g, 20.0 mmol) and 4-
bromophenacyl bromide (5.52 g, 20.0 mmol) in acetone (40 mL), 2c
was isolated (2.46 g, 41%) by filtration and recrystallization (EtOH)
as yellow prisms, m.p. 124◦C (ethanol). IR (KBr): ν˜ = 2988, 2934 (w),
2154 (m), 1658, 1585 (s), 1567 (m), 1486 (s), 1402, 1313 (w), 1289, 1180,
1071, 997, 811 (m) cm−1. 1H NMR (DMSO-d6, 300 MHz): δ = 4.88 (s, 2 H,
CH2), 7.66–7.71 (m, 2 H, Ar), 7.80–7.84 (m, 2 H, Ar). 13C NMR (DMSO-
d6, 75 MHz): δ = 35.0 (CH2), 103.8 (C), 128.3, 130.8 (CH), 132.0, 133.3,
194.5 (C). MS (EI, 70 eV): m/z (%) = 302 (5, [M + H]+ (80Se)), 234 (22),
183 (100), 155 (21), 77 (18). Anal. calcd. for C9H6BrNOSe (303.02): C,
35.78; H, 2.00; N, 4.64. Found: C, 35.89; H, 2.26; N, 3.80.
Desyl Selenocyanate (2d)
Starting with potassium selenocyanate (2.88 g, 20.0 mmol) and desyl
bromide (5.5 g, 20.0 mmol) in acetone (50 mL), 2d was isolated (2.75 g,
46%) by filtration and recrystallization (EtOH) as red needles, m.p.
124◦C (ethanol). IR (KBr): ν˜ = 3051, 2959 (w), 2150 (m), 1666 (s), 1595,
1
1450 (m), 1275 (s), 1143, 1004, 764 (m), 697, 620 (s) cm−1. H NMR
(DMSO-d6, 300 MHz): δ = 7.23 (s, 1 H, CH), 7.29–7.51 (m, 7 H, Ar),
7.59–7.65 (m, 1 H, Ar), 7.96–7.98 (m, 2 H, Ar). 13C NMR (DMSO-d6, 75
MHz): δ = 58.1 (CH), 104.0 (C), 128.6, 128.9, 129.3, 129.5, 129.6, 129.7
(CH), 133.0, 134.5, 136.6, 195.5 (C). MS (EI, 70 eV): m/z (%) = 301 (6,
[M + H]+ (80Se)), 195 (74), 167 (88), 151 (63), 105 (100, [C6H5CO]+), 90
(66), 77 (84, [C6H5]+). Anal. calcd. for C15H11NOSe (300.22): C, 60.01;
H, 3.69; N, 4.67. Found: C, 60.03; H, 4.38; N, 4.37.
3-(4-Chlorophenyl)-4-phenyl-3H-(selenazol-2-ylidene)amine
Hydrochloride (4a)
A mixture of 2a (1.12 g, 5.0 mmol), and 4-chloroaniline hydrochloride
(0.82 g, 5.0 mmol) in ethanol (50 mL) was refluxed for 5 h. The pre-
cipitated product was isolated by filtration, washed (ether), and dried

214
A. Bodtke et al.
in vacuo. Yield: 0.50 g (27%), green to grey prisms, m.p. 245–252◦C
(decomp., EtOH). IR (KBr): ν˜ = 3110 (m), 3051, 3009, 1615, 1528, 1490
(s), 1087, 885, 744, 724, 696 (m) cm−1. 1H NMR (DMSO-d6, 300 MHz):
δ = 7.17–7.31 (m, 6 H, 5-H, Ar-H), 7.48–7.57 (m, J= 9.0 Hz, 4 H, Ar-H),
8.98 (bs, 1 H, NH), 10.52 (bs, 1 H, NH). 13C NMR (DMSO-d6, 75 MHz):
δ = 108.1 (C-5), 128.2, 129.2, 129.6, 130.3 (CH), 130.5 (C), 130.7 (CH),
133.5, 135.0, 140.4, 173.8 (C). MS (EI, 70 eV): m/z (%) = 336 (40), 335
(47), 334 (94, [M–HCl]+ (35Cl, 80Se)), 333 (83), 332 (52), 331 (52), 330
(24), 214 (27), 102 (100). Anal. calcd. for C15H12Cl2N2Se (370.14): C,
48.68; H, 3.27; N, 7.57. Found: C, 48.37; H, 3.70; N, 7.69.
3-(3,5-Dichlorophenyl)-4-phenyl-3H-(selenazol-2-
ylidene)amine Hydrochloride (4b)
A mixture of 2a (1.12 g, 5.0 mmol), 3,5-dichloroaniline (0.81 g, 5.0 mmol),
and 3 drops of conc. hydrochloric acid in ethanol (30 mL) was refluxed for
10 h. The precipitated product was isolated by filtration, washed (ether),
and dried in vacuo. Yield: 0.42 g (21%), grey prisms, m.p. 263–269◦C (de-
comp., EtOH). IR (KBr): ν˜ = 3121, 3045, 2987 (m), 1627 (s), 1577, 1529,
1
1433 (m), 806, 744, 711, 696, 665 (w) cm−1. H NMR (DMSO-d6, 300
MHz): δ = 7.20–7.32 (m, 6 H, 5-H, Ar), 7.72–7.75 (m, 3 H, Ar), 9.23 (bs,
1 H, NH), 10.61 (bs, 1 H, NH). 13C NMR (DMSO-d6, 75 MHz): δ = 108.3
(C-5), 128.1, 128.2, 129.2, 129.5, 130.2 (CH), 134.9, 136.5, 139.7, 173.7
(C). MS (EI, 70 eV): m/z (%) = 372 (13), 371 (22), 370 (55), 369 (69), 368
(88, [M–HCl]+ (35Cl, 80Se)), 367 (100), 366 (50), 365 (53), 364 (24), 363
(13), 261 (11), 260 (35), 252 (10), 250 (53), 248 (82), 182 (19), 146 (18),
145 (27), 102 (59). C15H11Cl3N2Se (404.58).
3-Phenyl-4-(4-chlorophenyl)-3H-(selenazol-2-ylidene)amine
Hydrochloride (4c)
A mixture of 2b (1.30 g, 5.0 mmol) and aniline hydrochloride (0.65 g,
5.0 mmol) in ethanol (60 mL) was refluxed for 10 h. The precipitated
product was isolated by filtration, washed (ether), and dried in vacuo.
Yield: 0.24 g (13%), grey prisms, m.p. 268–271◦C (decomp., EtOH). IR
(KBr): ν˜ = 3023, 2961, 2937 (m), 1614 (m), 1527 (w), 1494 (s), 1090 (w),
744 (m) cm−1. 1H NMR (DMSO-d6, 300 MHz): δ = 7.19–7.20 (m, 2 H, Ar),
7.30–7.32 (m, 2 H, Ar), 7.34 (s, 1 H, 5-H), 7.41–7.50 (m, 5 H, Ar), 9.60
(bs, NH). 13C NMR (DMSO-d6, 75 MHz): δ = 108.7 (C-5), 127.7, 128.1
(CH), 129.2 (C), 129.8, 130.0, 130.8 (CH), 133.6, 134.1, 138.9, 173.4 (C).
MS (EI, 70 eV): m/z (%) = 335 (14), 334 (36, [M–HCl]+ (35Cl, 80Se)), 333
(51), 332 (20), 331 (27), 214 (62), 77 (100). C15H12Cl2N2Se (370.14).

Synthesis of 4-Aryl-2-imino-2H-selenazolines
215
3-(4-Chlorophenyl)-4-(4-chlorophenyl)-3H-(selenazol-2-
ylidene)amine Hydrochloride (4d)
A mixture of 2b (1.30 g, 5.0 mmol) and of 4-chloroaniline hydrochloride
(0.82 g, 5.0 mmol) in ethanol (20 mL) was refluxed for 5 h. The pre-
cipitated product was isolated by filtration, washed (ether), and dried
in vacuo. Yield: 0.31 g (15%), brown prisms, m.p. 255–275◦C (decomp.,
EtOH). IR (KBr): ν˜ = 3111, 2986, 1618, 1529, 1489 (s), 1093, 841 (m)
cm−1. 1H NMR (DMSO-d6, 300 MHz): δ = 7.19–7.23 (m, 2 H, Ar-H), 7.33
(s+d, 2 J(1H,77Se) = 41.3 Hz, 1 H, 5-H), 7.34–7.37 (m, 2 H, Ar), 7.49–7.59
(m, 4 H, Ar), 8.95 (bs, 1 H, NH), 10.38 (bs, 1 H, NH). 13C NMR (DMSO-
d6, 75 MHz): δ = 108.8 (C-5), 128.3 (CH), 129.4 (C), 130.4, 130.7, 131.4
(CH), 133.4, 134.1, 135.1, 139.2, 173.7 (C). MS (EI, 70 eV): m/z (%) = 372
(2), 371 (3), 370 (11), 369 (11), 368 (20, [M−HCl]+ (35Cl, 80Se)), 367 (16),
366 (10), 295 (17), 248 (23), 103 (100), 75 (57). C15H11Cl3N2Se (404.58).
3-(3,5-Dichlorophenyl)-4-(4-bromophenyl)-3H-(selenazol-2-
ylidene)amine Hydrochloride (4e)
A mixture of 2c (1.51 g, 5.0 mmol), 3,5-dichloroaniline (0.81 g, 5.0 mmol),
and 3 drops conc. hydrochloric acid in ethanol (30 mL) was refluxed
for 10 h. The precipitated product was isolated by filtration, washed
(ether), and dried in vacuo. Yield: 40 mg (2%), yellow prisms, m.p. 155–
170◦C (decomp., EtOH). IR (KBr): ν˜ = 3073, 3053 (w), 1604, 1577 (s),
1
1485, 1432, 1346, 1114, 1058, 831, 802, 748, 744 (m) cm−1. H NMR
(DMSO-d6, 300 MHz): δ = 6.64 (s, 1 H, 5-H), 7.11–7.13 (m, 2 H, Ar),
7.25 (d, J= 1.8 Hz, 2 H, Ar), 7.45–7.48 (m, 3 H, Ar), 8.88 (bs, 1 H, NH).
13C NMR (DMSO-d6, 75 MHz): δ = 100.1 (C-5), 121.5 (C), 126.8, 128.1,
130.1, 131.3 (CH), 132.0, 133.5, 137.8, 140.7, 160.2 (C). MS (EI, 70 eV):
m/z (%) = 450 (26), 449 (35), 448 (60), 447 (69, [M–HCl]+ (79Br, 35Cl,
80Se)), 446 (59), 445 (61), 444 (30), 443 (23), 340 (28), 338 (17), 330
(29), 328 (65), 326 (39), 146 (43), 145 (68), 102 (23). C15H10BrCl3N2Se
(483.48).
3-(4-Chlorophenyl)-4-(4-bromophenyl)-3H-(selenazol-2-
ylidene)amine Hydrochloride (4f)
A mixture of 2c (1.51 g, 5.0 mmol) and of 4-chloroaniline hydrochloride
(0.82 g, 5.0 mmol) in ethanol (20 mL) was refluxed for 5 h. The precip-
itated product was isolated by filtration, washed (ether), and dried in
vacuo. Yield: 0.25 g (4-chloroanilinium chloride could not be separated,
4f/4-ClC6H4NH3Cl = 1.3:1). IR (KBr): ν˜ = 3112, 3000, 1615, 1527 (m),
1
1489 (s), 1094 (m), 840, 822 (w) cm−1. H NMR (DMSO-d6, 300 MHz):

216
A. Bodtke et al.
δ = 7.11–7.15 (m, 2 H, Ar), 7.32 (s, 1 H, 5-H), 7.43–7.58 (m, 6 H, Ar),
8.98 (bs, 1 H, NH), 10.81 (bs, 1 H, NH). 13C NMR (DMSO-d6, 75 MHz):
δ = 109.1 (C-5), 122.9 (C), 123.4, 129.5 (CH), 129.8, 129.9 (C), 130.4,
130.8, 131.3, 131.7 (CH), 133.4, 134.2, 135.2, 139.1, 173.9 (C). MS (EI,
70 eV): m/z (%) = 417 (27), 416 (35), 415 (87), 414 (79), 413 (100, [M–Cl]+
(79Br, 35Cl, 80Se)), 411 (80), 410 (51), 409 (37), 408 (16), 296 (22), 294
(97), 292 (71). C15H11BrCl2N2Se (449.04).
3-(4-Chlorophenyl)-4,5-diphenyl-3H-(selenazol-2-
ylidene)amine Hydrochloride (4g)
A mixture of 2d (1.50 g, 5.0 mmol) and 4-chloroaniline hydrochloride
(0.82 g, 5.0 mmol) in ethanol (25 mL) was refluxed for 10 h. The pre-
cipitated product was isolated by filtration, washed (ether), and dried
in vacuo. Yield: 0.22 g (10%), colourless prisms, m.p. 255–270◦C (de-
comp., EtOH). IR (KBr): ν˜ = 3191 (m), 3023 (w), 1614, 1598, 1575, 1490,
1
1402, 1341 (m), 1090 (w), 732, 697 (m) cm−1. H NMR (DMSO-d6, 300
MHz): δ = 7.12–7.29 (m, 10 H, Ar), 7.49–7.57 (m, 4 H, Ar), 9.18 (bs, 1 H,
NH), 10.87 (bs, 1 H, NH). 13C NMR (DMSO-d6, 75 MHz): δ = 122.0 (C-
5), 128.3, 128.6, 128.7, 129.3, 129.7, 130.0, 130.8, 131.1 (Ar-H), 133.7,
134.9, 135.6, 170.8 (C). MS (EI, 70 eV): m/z (%) = 414 (12), 413 (43),
412 (45), 411 (100), 410 (70, [M–HCl]+ (35Cl, 80Se)), 408 (55), 407 (42),
406 (25), 405 (10), 216 (33), 215 (14), 214 (100), 178 (38), 165 (19). Anal.
calcd. for C21H16Cl2N2Se (446.24): C, 56.52; H, 3.61; N, 6.28. Found: C,
56.25; H, 3.81; N, 6.07.
4-(4-Chlorophenyl)-2-iminoselenazol-3-ol Hydrochloride (4h)
A mixture of 2b (1.30 g, 5.0 mmol) and hydroxyl amine hydrochloride
(0.35 g, 5.0 mmol) in ethanol (50 mL) was refluxed for 10 h. The precip-
itated product was isolated by filtration, washed (ether), and dried in
vacuo. Yield: 0.27 g (17%), colourless prisms, m.p. 215–223◦C (decomp.,
EtOH). IR (KBr): ν˜ = 3416, 3284, 3244, 3176 (m), 3079 (s), 2679, 2622
1
(m), 1606 (s), 1545, 1485, 1092, 839, 740 (m) cm−1. H NMR (DMSO-
d6, 300 MHz): δ = 7.25 (s+d, 2 J(1H,77Se) = 40.7 Hz, 1 H, 5-H), 7.54–
7.58 (m, J= 8.6 Hz, 2 H, Ar), 7.68–7.72 (m, J= 8.6 Hz, 2 H, Ar), 9.88
(bs, 2 H, 2 NH), 12.81 (bs, 1 H, OH). 13C NMR (DMSO-d6, 75 MHz):
δ = 104.6 (1 J(13C,77Se) = 108.6 Hz, C-5), 128.0 (C), 128.4, 130.4 (Ar),
134.2, 137.4 (C), 167.1 (1 J(13C,77Se) = 151.2 Hz, CN). C9H8Cl2N2OSe
(310.04).

Synthesis of 4-Aryl-2-imino-2H-selenazolines
217
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