Selenium-containing heterocycles: Part 2. Reactions of 3-amino-4,6- dimethyl-selenolo[2,3-b]pyridine-2-carbonitrile and related fused tetracyclic systems

Article abstract of DOI:10.3184/030823409X401114

A novel series of pyrido[3′,2′:4,5]selenolo[3,2-d]pyrimidine, 7,9-dimethylpyrido [3′,2′:4,5]selenolo[3,2-d]pyrimidine-2,4-(1H,3H)- dithione, 7,9-dimethylpyrido[3′,2′:4,5]selenolo[2,3-e]tetrazolo[1,5- c]pyrimidine-6(5H)-thione, 9,11-dimethyl-pyrido[3′,2′4,

Full text of DOI:10.3184/030823409X401114

56 RESEARCH PAPER
JANUARY, 56–59
JOURNAL OF CHEMICAL RESEARCH 2009
Selenium-containing heterocycles: Part 2. Reactions of 3-amino-4,6-dimethyl-
selenolo[2,3-b]pyridine-2-carbonitrile and related fused tetracyclic systems
Shams H. Abdel-Hafez*, Ragaa A. Ahmed, Mohamed A. Abdel-Azim and Khairy M. Hassan
Chemistry Department, Faculty of Science, Assiut University, Assiut 71516, Egypt
A novel series of pyrido[3',2':4,5]selenolo[3,2-d]pyrimidine, 7,9-dimethylpyrido [3',2':4,5]selenolo[3,2-d]pyrimidine-2,4-
(1H,3H)-dithione, 7,9-dimethylpyrido[3',2':4,5]selenolo[2,3-e]tetrazolo[1,5-c]pyrimidine-6(5H)-thione, 9,11-dimethyl-
pyrido[3',2':4,5]selenolo[2,3-e][1,2,4]triazolo[1,5-c]pyrimidine, 7,9-dimethylpyrido[3',2':4,5]selenolo[2,3-e]imidazo[1,2-c]
pyrimidine and 10,12-dimethylpyrido[3'',2'':4',5']selenolo[3',2':4,5]pyrimido[1,6-a]pyrimidine derivatives were prepared
from 3-amino-4,6-dimethylselenolo[2,3-b]pyridine-2-carbonitrile.
Keywords: o-aminonitriles, fused selenophenes, imidazoles, pyridines, pyrimidines, tetrazoles, 1,2,4-triazoles
A literature survey indicates that only few publications are
concerned with the incorporation of a selenium atom in the
pyridine ring.1-5 Consequently, the synthesis of new classes
of heterocyclic systems containing the selenolopyridine
moiety may be considered to be a virgin research area.
Moreover, previous work in our laboratory describes
the synthesis of pyrimidoselenolo[2,3-b]quinoline6 and
previously described by Litvinov.2 Compound 2 reacted with
FDUERQꢀ GLVXO¿GHꢀ DQGꢀ SKHQ\Oꢀ LVRWKLRF\DQDWHꢀ WRꢀ JLYHꢀ WKHꢀ ꢄꢃꢅꢁ
dimethylpyrido[3',2':4,5]selenolo[3,2-d]pyrimidine-2,4-
(1H,3H)-dithione (3) and 3,4-dihydro-7,9-dimethyl-3-phenyl-
4-iminopyrido[3',2':4,5]selenolo[3,2-d]pyrimidine-2(1H)-
thione (4), respectively (Scheme 1). The reactivity of the
thione group of compound 4 was tested by alkylation with
allyl bromide and methyl iodide which afforded derivatives
(5a,b) respectively.
Heating of compound 2 with sodium azide and ammonium
FKORULGHꢀ LQꢀ '0)ꢀ IROORZHGꢀ E\ꢀ DFLGL¿FDWLRQꢀ RIꢀ WKHꢀ UHDFWLRQꢀ
mixture led to the formation of the tetrazolyl compound
6. The IR spectrum of compound 6 showed characteristic
bands at 3300, 3400, 3500 cm-1 for NH2 and NH, and the
disappearance of the cyano group of compound 2. The mass
spectrum of 6 showed a molecular ion peak at m/z 294
(M+, 100) which is in agreement with its molecular formula
(C10H10N6Se). When compound 6 was allowed to react
ZLWKꢀ FDUERQꢀ GLVXO¿GHꢀ DQGꢀ ZLWKꢀ DURPDWLFꢀ DOGHK\GHVꢃꢀ WKHꢀ
tetrazolopyridoselenolopyrimidine derivatives 7 and 8a–c
respectively were obtained in good yields.
pyrimidoselenolo[2,3-c]pyridazine
derivatives,7
which
indicate that certain compounds bearing the selenophene
DQGꢀTXLQROLQHꢀRUꢀS\ULGD]LQHꢀQXFOHXVꢀSRVVHVVꢀVLJQL¿FDQWꢀDQWLꢁ
LQÀDPPDWRU\ꢀDQGꢀDQDOJHVLFꢀDFWLYLWLHVꢀZLWKꢀVWURQJꢀIXQJLFLGDOꢀ
HIIHFWVꢂꢀ 7KHUHIRUHꢃꢀ QHZꢀ HI¿FLHQWꢀ V\QWKHVHVꢀ DUHꢀ DQꢀ DWWUDFWLYHꢀ
goal of chemical research. In Part 18 we published the
synthesis of selenolo[2,3-b]pyridine, pyrido[3',2':4,5]selenolo
[3,2-d]pyrimidine,
7,8-dihydro-2,4-dimethylpyrrolo[1,2-a]
and
pyrido[3',2':4,5]selenolo[3,2-d]pyrimidin-10(6H)-one
7,9-dimethylpyrido[3',2':4,5]selenolo[3,2-d][1,2,4]triazolo
[4,3-c]pyrimidine derivatives. The aforementioned properties
of selenium organic compounds prompted further efforts in
continuation of our work6-10 on the quest for novel heterocyclic
systems containing selenium exhibiting biological activity,
and we report herein new classes of fused selenium-containing
derivatives containing the selenolo[2,3-b]pyridine system.
In contrast, the reaction of tetrazolyl derivative 6 with
triethyl orthoformate produced the azidopyrimidine derivative
(10) (Scheme 2). The structure of compounds 7, 8a–c and
10 were assigned by elemental and spectral analyses. The IR
spectrum of compound 10 showed a characteristic band at
2150 cm-1 for the azido group.
Results and discussion
Our approach to the synthesis of the target compounds
started from 3-amino-4,6-dimethylselenolo[2,3-b]pyridine-
2-carbonitrile (2) which was prepared from the selenol 1 as
S
Me
Me
Me
NH2
HN
Se
CN
a
NH
S
b
CN
Me
N
SeH
Se
Me
c
N
Me
N
N
3
1
2
SR
S
Me
N
Me
N
HN
Se
NPh
NH
d
NPh
NH
Se
5a,b
Me
Me
4
5a, R = -CH2-CH=CH2
5b, R = CH3
Reagents: a, ClCH2CN; b, CS2; c, PhNCS; d, Allyl-Br or Me-I
Scheme 1
* Corresponnddeenntt..E-mail: sabdel68@yahoo.co.uk, shams@aun.edu.eg

JOURNAL OF CHEMICAL RESEARCH 2009 57
Me
N
Me
N
NH
Se
c
2
H
N
N
N
N
a
d
2
N
N
Se
Me
N
N
Me
N
9
6
b
S
N
H
Ar
Me
N
Me
N
Me
N
HN
Se
HN
Se
8a, Ar = C H
6 5
N
N
8b, Ar = p-HOC H
6 4
N
N
N
N
8c, Ar = p-ClC H
6
4
N
N
N
N
3
Se
Me
Me
Me
10
8a-c
7
Reagents: a, NaN /NH Cl; b, CS ; c, ArCHO; d, triethyl orthoformate
3
4
2
Scheme 2
Reaction of compound 2 with triethyl orthoformate afforded
the methanimidate derivative 11, which was prepared as
previously described.8 Heating of compound 11 with equimolar
amounts of cyanoacetic acid or benzoic acid hydrazide
furnished the 2-(substituted alkyl/phenyl)-7,9-dimethylpyrido
[3',2':4,5]selenolo[2,3-e][1,2,4]triazolo[1,5-c]pyrimidine
derivatives (12a,b). Treatment of 12a,b with hydrochloric
acid induced pyrimidine ring opening11 to furnish the amines
13a,b in excellent yield (Scheme 3).
Finally, stirring of 11 with benzylamine led to amino-
deethoxylation accompanied by cyclisation to give 3-benzyl-
7,9-dimethylpyrido[3',2':4,5]selenolo[3,2-d]pyrimidin-4(3H)-
imine (14), while heating 11 with urea in acetic acid produced
N'-carboxamido-N-(2-cyano-4,6-dimethylselenolo[2,3-b]
pyridin-3-yl)methanimidate (15) rather than the expected
fused pyrimidine (16) (Scheme 3). The IR spectrum of
compound 15 showed characteristic bands at 3200–3400 cm-1
(NH, NH2) and 2200 cm-1 for the CN group. The mass
spectrum showed a molecular ion peak at m/z 321 (M+, 0.5)
in agreement with its molecular formula (C12H11N5OSe).
The 1H NMR showed a characteristic peak at: G 8.7 due to the
CH=N group. Incorporation of the imidazoline and pyrimidine
moieties into the selenolopyridine structure was successfully
accomplished by reacting 11 with ethylenediamine and
propylenediamine to give the intermediate derivatives 17a,b
which were boiled in ethanol to give 2,3-dihydro-7,9-dimethyl-
pyrido[3',2':4,5]selenolo[2,3-e]imidazo[1,2-c]pyrimidine
(18a) and 3,4-dihydro-8,10-dimethyl-2H-pyrido[3'',2'':4',5']
selenolo[3',2':4,5]pyrimido[1,6-a]pyrimidine (18b) respectively.
Experimental
0HOWLQJꢀ SRLQWVꢀ ZHUHꢀ GHWHUPLQHGꢀ XVLQJꢀ Dꢀ .RÀHUꢀ PHOWLQJꢀ SRLQWꢀ
apparatus. IR spectra were recorded on
a Pye-Unicam SP3-
100 instrument in KBr. The mass spectra (EI, 70 eV, ion source
Me
N
Me
NH
2
N
N
N
NH
c
R
N
R
N
Se
Se
Me
N
Me
N
12a,b
13a,b
12,13 a: R = CH CN
2
b: R = Ph
b
Me
N
Me
Me
N
N=CHOEt
CN
N=CHNHCONH
CN
2
N
N
CONH
2
e
a
2
NH
Se
Se
Se
16
Me
Me
N
Me
11
15
e
f
Me
N
Me
Me
N
N
N
CH Ph
XCH NH
2 2
N
N
N
2
X
g
N
NH
NH
Se
Se
Se
Me
Me
N
Me
N
14
17a,b
18a,b
17,18 a: X = CH
2
2 2
b: X = (CH )
Reagents: a, HC(OEt) ; b, RCONHNH ; c, 20% HCl/H O; d, PhCH NH ; e, urea; f, H N-X-CH NH ; g, EtOH, D
3
2
2
2
2
2
2
2
Scheme 3

58 JOURNAL OF CHEMICAL RESEARCH 2009
temperature 210°C) were recorded on a JEOL JMS600 instrument.
1H NMR spectra were obtained on a Varian spectrometer (90 MHz)
using tetramethylsilane as internal reference. 13C NMR spectra
were recorded on a Mercury-300BB NMR300 at Cairo University.
Elemental analyses were obtained on an Elementar Vario EL 1150 C
analyser. Purity of the compounds was checked by TLC.
formed on cooling was collected and recrystallised from ethanol to
give compounds 8a–c respectively.
5-Phenyl compound 8a: Formed yellow crystals (0.64 g, 85%), m.p:
172–174°C. IR: Qmax 3300 cm-1 (NH). NMR (DMSO-d6): GH 2.5 (s, 3H,
CH3), 2.8 (s, 3H, CH3), 7.3–7.5 (m, 7H, ArH, CH-pyridine, pyrimidine).
MS: m/z (%) 382 (M+, 20). Anal: Calcd for C17H14N6Se (381.33): C,
53.53; H, 3.70; N, 22.04. Found: C, 53.44; H, 3.56; N, 21.87%.
4-Hydroxyphenyl compound 8b: Yellow crystals (0.68 g, 86%),
m.p: 204–206°C. IR: Qmax 3300 cm-1 (NH). NMR (TFA): GH 3.2 (s,
3H, CH3), 3.3 (s, 3H, CH3), 6.2 (s, 1H, CH pyrimidine), 7.6–7.8 (m,
5H, ArH, CH-pyridine). MS: m/z (%) 398 (M+, 16). Anal: Calcd for
C17H14N6OSe (397.20): C, 51.40; H, 3.55; N, 21.16. Found: C, 50.99;
H, 3.24; N. 20.97%.
Compounds 1, 21,2,5 and 118 were prepared as previously
described.
7,9-Dimethylpyrido[3',2':4,5]selenolo[3,2-d]pyrimidine-2,4(1H,
3H)-dithione (3): Compound 2ꢀꢆꢇꢂꢈꢉꢀJꢃꢀꢊꢀPPROꢋꢀDQGꢀFDUERQꢀGLVXO¿GHꢀ
(5 mL) in pyridine (10 mL) were gently heated on a water bath
for 6 h. The solid product that formed while hot was collected and
recrystallised from DMF/water mixture, forming yellow crystals (0.21
g, 65%), m.p. >300°C. IR: Qmax 3100 cm-1 (NH). NMR (TFA): GH
3.0 (s, 3H, CH3), 3.2 (s, 3H, CH3), 7.7 (s, 1H, CH-pyridine). MS: m/z
(%) 327 (M+, 100). Anal: Calcd for C11H9N3S2Se (326.33): C, 40.48;
H, 2.78; N, 12.87; S, 19.65. Found: C, 40.33; H, 2.59; N, 12.58; S,
19.56%.
3,4-Dihydro-7,9-dimethyl-3-phenyl-4-iminopyrido[3',2':4,5]selenolo
[3,2-d]pyrimidine 2(1H)-thione (4): Compound 2 (0.250 g, 1 mmol)
and phenyl isothiocyanate (0.125 mL, 1 mmol) were gently heated
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formed on cooling was collected and recrystallised from acetic acid
to give orange crystals of 4 (0.32 g, 85%), m.p >300°C. IR: Qmax
3200 cm-1 (NH). NMR (TFA): GH 3.0 (s, 3H, CH3), 3.2 (s, 3H, CH3),
7.5–7.8 (m, 6H, ArH, CH-pyridine). MS: m/z (%) 386 (M+, 36). Anal:
Calcd for C17H14N4SSe (385.38): C, 52.97; H, 3.66; N, 14.54; S,
8.32. Found: C, 52.55; H, 3.34; N, 14.24; S, 7.98%.
4-Chlorophenyl compound 8c: Pale yellow crystals (0.74 g, 90%)
from ethanol, m.p: 152–154°C. IR: Qmax 3300 cm-1 (NH). NMR
(TFA): GH 3.2 (s, 3H, CH3), 3.3 (s, 3H, CH3) 7.5–7.6 (m, 6H, 4H
ArH, 1H CH-pyridine, 1H pyrimidine). MS: m/z (%) 417 (M+, 17).
Anal: Calcd for C17H13ClN6Se (415.77): C, 49.10; H, 3.15; Cl, 8.52;
N, 20.21. Found: C, 48.92; H, 3.11; Cl, 8.32; N, 20.01%.
7,9-Dimethyl-4-azidopyrido[3',2':4,5]selenolo[3,2-d]pyrimidine
(10): The tetrazole 6 (0.586 g, 2 mmol) and triethyl orthoformate
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formed while hot was collected and recrystallised from ethanol
giving yellow crystals of 10 (0.52 g, 87%), m.p: 182–184°C. IR: Qmax
2150 cm-1 (N3). NMR (DMSO-d6): GH 2.6 (s, 3H, CH3), 2.8 (s, 3H,
CH3), 7.2 (s, 1H, CH-pyridine), 10.2 (s, 1H, CH-pyrimidine). MS:
m/z (%) 304 (M+, 44). Anal: Calcd for C11H8N6Se (303.21): C, 43.57;
H, 2.66; N, 27.72. Found: C, 43.26; H, 2.21; N, 27.43%.
2-(Cyanomethyl/phenyl)-7,9-dimethylpyrido[3c,2c:4,5]selenolo[2,3-e]
[1,2,4]triazolo[1,5-c]pyrimidine (12a,b): general procedure
A mixture of the iminoether 118 (1.53 g, 5 mmol) and cyanoacetic
acid or benzoic acid hydrazides (5 mmol) in acetic acid (20 mL)
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cooling in the case of 12a and that formed while hot in case of 12b
were collected and recrystallised from the indicated solvent to give
compounds 12a,b.
2-Alkylthio-7,9-dimethyl-3-phenylpyrido[3c,2c:4,5]selenolo[3,2-d]
pyrimidin-4(3H)-imine (5a,b): general procedure
Allyl iodide or methyl iodide (4 mmol) was added to a mixture of 4
(1.54 g, 4 mmol) and sodium acetate trihydrate (1.36 g, 10 mmol) in
HWKDQROꢀꢆꢍꢇꢀP/ꢋꢃꢀDQGꢀWKHꢀUHDFWLRQꢀPL[WXUHꢀZDVꢀKHDWHGꢀXQGHUꢀUHÀX[ꢀ
for 2 h. After cooling the reaction mixture was poured into ice-water
and the precipitate that formed was collected and recrystallised from
ethanol to give compounds 5a,b respectively.
Cyanomethyl compound 12a: Yellow crystals (1.45 g, 85%),
m.p >300°C from acetic acid. IR: Qmax 2200 cm-1 (CN). NMR (TFA):
GH 3.2 (s, 3H, CH3), 3.6 (s, 3H, CH3), 4.7 (s, 2H, CH2), 8.0 (s, 1H,
CH-pyridine), 9.8 (s, 1H, CH-pyrimidine). MS: m/z (%) 342 (M+,
100). Anal: Calcd for C14H10N6Se (341.26): C, 49.27; H, 2.95; N,
24.63. Found: C, 49.07; H, 2.53; N, 24.95%.
Allylthio compound 5a: Yellow crystals (1.53 g, 90%), m.p. 192–
194°C. IR: Qmax 3200 (NH). NMR (TFA): GH 3.0 (s, 3H, CH3), 3.3
(s, 3H, CH3), 4.2 (d, 2H, SCH2), 5.2–5.4 (m, 3H, CH=CH2), 7.3–7.7
(m, 6H, 5H ArH, 1H CH-pyridine). MS: m/z (%) 426 (M+, 44). Anal:
Calcd for C20H18N4SSe (425.45): C, 56.45; H, 4.27; N, 13.17; S,
7.53. Found: C, 56.50; H, 4.28; N, 12.98; S, 7.19%.
Phenyl compound 12b: White crystals (1.55 g, 82%)separated
from DMF/water, m.p >300°C. IR: Qmax 3050 cm-1 (CH-arom). NMR
(TFA): GH 3.1 (s, 3H, CH3), 3.5 (s, 3H, CH3) 7.8–8.2 (m, 6H, 5H
ArH, 1H CH-pyridine), 9.9 (s, 1H, CH-pyrimidine). MS: m/z (%) 379
(M+, 100). Anal: Calcd for C18H13N5Se (378.32): C, 57.14; H, 3.47;
N, 18.51. Found: C, 56.88; H, 3.25; N, 18.22%.
Methylthio compound 5b: Pale yellow crystals (1.42 g, 89%), m.p
212–214°C: IR: Qmax 3200 cm-1 (NH). NMR (DMSO-d6): GH 2.3 (s,
3H, SCH3), 2.5 (s, 3H, CH3), 2.8 (s, 3H, CH3), 7.4–7.6 (m, 5H, ArH),
7.2 (s, 1H, CH-pyridine), 9.5 (s, 1H, NH); GH 19.8 (SCH3), 23.8, 33.0
(2 CH3-pyridine), 110.55, 117.2, 122.3, 123.8, 125.7, 128.4 (C-Aryl),
134.3, 138.7, 147.5 (C-selenophene), 156.5, 158.8, 159.3, 163.8
(C=N pyrimidine), 165.85 (C=NH pyrimidine). MS: m/z (%) 400
(M+, 89). Anal: Calcd for C18H16N4SSe (399.40): C, 54.12; H, 4.04;
N, 14.03; S, 8.02. Found: C, 54.50; H, 4.28; N, 13.98; S, 7.88%.
3-Amino-4,6-dimethyl-2-(tetrazol-5-yl)selenolo[2,3-b]pyridine(6):
The aminonitrile 2 (1.25 g, 5 mmol), sodium azide (0.4 g, 6 mmol)
and ammonium chloride (0.32 g, 6 mmol) in DMF (15 mL) were
heated on a water bath for 5 h. The reaction mixture was cooled and
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collected and recrystallised from ethanol to give yellow crystals of
the tetrazole 6 (1.20 g, 82%), m.p. 273–275°C. IR: Qmax 3300, 3400,
3500 cm-1 (NH2, NH). NMR (TFA): GH 3.1 (s, 3H, CH3), 3.2 (s, 3H,
CH3), 7.6 (s, 1H, CH-pyridine). MS: m/z (%) 294 (M+, 100). Anal:
Calcd for C10H10N6Se (293.22) C, 40.95; H, 3.44; N, 28.66. Found:
C, 40.65; H, 3.36; N, 28.45%.
3-Amino-2-[(5-(cyanomethyl/phenyl)-1,2,4-triazol-3-yl]-4,6-
dimethylselenolo[2,3-b]pyridine (13a,b): general procedure
The tetracyclic compound 12a or 12b (5 mmol) in 20% aqueous
K\GURFKORULFꢀDFLGꢀꢆꢈꢇꢀP/ꢋꢀZDVꢀKHDWHGꢀXQGHUꢀUHÀX[ꢀIRUꢀꢍꢀKꢂꢀ7KHꢀVROLGꢀ
product that formed while hot was collected and recrystallised from
dioxan to give compounds 13a,b.
Cyanomethyl compound 13a: Golden crystals (1.42 g, 86%), m.p.
242–244°C. IR: Qmax 2200 (CN), 3400–3500 cm-1 (NH, NH2). NMR
(TFA): GH 2.9 (s, 3H, CH3), 3.2 (s, 3H, CH3), 4.7 (s, 2H, CH2CN), 7.6
(s, 1H, CH-pyridine). MS: m/z (%) 333 (M+ + 1, 100). Anal: Calcd
for C13H12N6Se (331.27): C, 47.13; H, 3.65; N, 25.37. Found: C,
46.91; H, 3.25; N. 25.18%.
Phenyl compound 13b separated as yellow crystals (1.47 g, 80%).
m.p >300°C. IR: Qmax 3400–3500 cm-1 (NH, NH2). NMR (TFA): GH 3.2
(s, 3H, CH3), 3.5 (s, 3H, CH3) 7.8–8.4 (m, 6H, 5H ArH, 1H CH-pyridine).
MS: m/z (%) 369 (M+, 100). Anal: Calcd for C17H15N5Se (368.33): C,
55.43; H, 4.11; N, 19.01. Found: C, 55.15; H, 3.99; N 18.86%.
7,9-Dimethylpyrido[3c,2c:4,5]selenolo[2,3-e]tetrazolo[1,5-c]
pyrimidine-5(6H)-thione (7): The tetrazole 6 (0.586 g, 2 mmol) was
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(10 mL) for 6 h. The solid product that formed was collected and
recrystallised from DMF-water mixture to give yellow crystals of the
3-Benzylamino-7,9-dimethylpyrido[3c,2c:4,5]selenolo[3,2-d]
pyrimidin-4(3H)-imine (14)
1
thione 7 (0.48 g, 72%), m.p >300°C. H NMR (TFA): G 3.0 (s, 3H,
CH3), 3.3 (s, 3H, CH3) 7.8 (s, 1H, CH-pyridine). MS: m/z (%) 336
(M+, 37). Anal: Calcd for C11H8N6SSe (335.28): C, 39.40; H, 2.40;
N, 25.07; S, 9.56. Found: C, 39.59; H, 2.51; N, 24.98; S, 9.40%.
Amixtureofcompound11 (1.53g,5mmol)andbenzylamine(0.54mL,
5 mmol) in dioxan (10 mL) was stirred at room temperature for
4 h. the solid product that formed was collected and recrystallised
from ethanol to give compounds 14 as white crystals (1.68 g, 92%),
m.p: 173–175°C. IR: Qmax 3200 (NH), 3050 (CH-arom). 1H NMR
(DMSO-d6): G 2.6 (s, 3H, CH3), 2.9 (s, 3H, CH3), 4.8 (s, 2H, CH2Ph)
7.1–7.3 (m, 6H, 5H ArH, 1H CH-pyridine), 8.2 (s, 1H, NH), 8.5 (s,
1H, CH-pyrimidine). MS: m/z (%) 368 (M+, 100). Anal: Calcd for
C18H16N4Se (367.34) Calcd. C, 58.85; H, 4.39; N, 15.25. Found: C,
58.43; H, 4.57; N, 14.96%.
5-Aryl-5,6-dihydro-7,9-dimethylpyrido[3',2':4,5]selenolo[2,3-e]tetrazolo
[1,5-c]pyrimidine (8a–c): general procedure
To a mixture of compound 6 (0.586 g, 2 mmol) and benzaldehyde,
p-hydroxybenzaldehyde or p-chlorobenzaldehyde (2 mmol) in
ethanol (15 mL), a few drops of piperidine were added. The reaction
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JOURNAL OF CHEMICAL RESEARCH 2009 59
Nc-Carboxamido-N-(2-cyano-4,6-dimethylselenolo[2,3-b]pyridin-3-
yl)methanimidate (15).
CH3), 3.5 (s, 3H, CH3), 4.5 (m, 2H, CH2-imidazole), 5.2 (m, 2H, CH2-
imidazole), 7.2 (s, 1H, CH-pyridine), 8.1 (s, 1H, CH-pyrimidine). MS:
m/z (%) 304 (M+, 86). Anal: Calcd for C13H12N4Se (303.25): C, 51.48;
H, 3.99; N, 18.47. Found: C, 51.07; H, 3.98; N, 18.47%.
8,10-Dimethylpyrido[3",2":4',5']selenolo[3',2':4,5]pyrimido[1,6-a]
pyrimidine (18b): Crystallised from ethanol as yellow crystals (1.42 g,
90%), m.p. 282–284°C. IR: Qmax 3050 cm-1 (CH-arom). NMR (TFA):
GH 2.6 (m, 2H, CH2-pyrimidine), 3.1 (s, 3H, CH3), 3.4 (s, 3H, CH3),
4.0 (m, 2H, CH2-pyrimidine), 4.6 (m, 2H, CH2-pyrimidine), 7.8 (s,
1H, CH-pyridine), 8.7 (s, 1H, CH-pyrimidine). MS: m/z (%) 318
(M+, 100). Anal: Calcd for C14H14N4Se (317.28): C, 52.99; H, 4.45;
N, 17.66. Found: C, 52.50; H, 4.33; N, 17.72%.
A mixture of compound 11 (1.53 g, 5 mmol) and urea (0.3 g, 5 mmol)
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formed on cooling was collected and recrystallised from acetic
acid giving compound 15 as yellow crystals, (1.39 g, 87%), m.p:
242–244°C. IR: Qmax 3200–3400 (NH, NH2), 2200 cm-1 (CN).
NMR (TFA): GH 3.0 (s, 3H, CH3), 3.2 (s, 3H, CH3), 7.8 (s, 1H, CH-
pyridine), 8.7 (s, 1H, CH=N). MS: m/z (%) 321 (M+, 0.5), 277 (M+-
CONH2, 15). Anal: Calcd for C12H11N5OSe (320.24): C, 45.00; H,
3.46, N, 21.87. Found: C, 44.78; H, 3.92; N, 21.55%.
3-(2-Aminoethyl/3-aminopropyl)-3,4-dihydro-4-imino-7,9-dimethyl-
pyrido[3c,2c:4,5]selenolo[3,2-d]pyrimidin-4(3H)-imine
(17a,b):
general procedure
Received 2 August 2008; accepted 6 December 2008
Paper 08/0096 doi: 10.3184/030823409X401114
Published online: 23 January 2009
A mixture of compound 11 (1.53 g, 5 mmol) and the appropriate
diamine (5 mmol) in dioxan (10 mL) was stirred at room temperature
for 4 h. The solid product (17a,b) that formed was collected
and dried.
Aminoethyl compound 17a: White powder (1.31 g, 82%), m.p
undetermined (on heating cyclised to compound 18a). IR: Qmax 3200–
3400 cm-1 (NH, NH2). NMR (TFA): GH 3.2 (s, 3H, CH3), 3.5 (s, 3H,
CH3), 4.1 (m, 2H, CH2), 5.2 (m, 2H, CH2), 8.0 (s, 1H, CH-pyridine),
8.9 (s, 1H, CH-pyrimidine). MS (FAB): m/z (%) 321 (M+, 10), 304
(M+-NH3, 60).
Aminopropyl compound 17b: White powder (1.35 g, 81%), m.p
undetermined (on heating cyclised to compound 18b). IR: Qmax
3200–3400 cm-1 (NH, NH2). NMR (TFA): GH G 2.4 (m, 2H, CH2), 3.3
(s, 3H, CH3), 3.7 (s, 3H, CH3), 4.1(m, 2H, CH2), 4.9 (m, 2H, CH2),
7.6 (s, 1H, CH-pyridine), 8.9 (s, 1H, CH-pyrimidine). MS (FAB): m/z
(%) 335 (M+, 18), 318 (M+-NH3, 30).
References
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V.P. Litvinov, V. Yu. Mortikov, Yu.A. Sharanin and A.M. Shestopalov,
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V.P. Litvinov, Russian Chem. Rev., 1997, 66, 923-951.
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V.P. Litvinov, S.G. Krivokolysko and V.D. Dyachenko, Chem. Heterocycl.
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Sh.H. Abdel-Hafez, Sh.A. Abdel-Mohsen and Y.A. El-Ossaily,
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2
3
4
5
6
7
8
Cyclisation reactions; preparation of 18a,b: general procedure
Compound 17a (1.6 g, 5 mmol) or 17b (1.67 g, 5 mmol) was boiled
in ethanol for 5 min and the solution left to cool. The crystals that
formed on cooling was collected and recrystallised from the proper
solvent giving compounds 18a, b.
9
10 Sh.H. Abdel-Hafez, Russian J. Org. Chem., 2005, 41, 396-401.
11 P.G. Baraldi, F.Fruttarolo, M.A. Tabrizi, D. Preti, R. Romagnoli,
H. El-Kashef, Moorman, K. Varani, S. Gessi, S. Merighi and P.A. Borea,
J. Med. Chem., 2003, 46, 1229-1241.
7,9-Dimethylpyrido[3',2':4,5]selenolo[2,3-e]imidazo[1,2-c]
pyrimidine (18a):Yellow crystals (1.36 g, 90%) from ethanol, m.p. 291–
293°C. IR: Qmax 3050 cm-1 (CH-arom). NMR (TFA): GH 3.2 (s, 3H,