Fusion reactions of N-heterocyclic moieties to thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidines

Article abstract of DOI:10.1135/cccc19960147

Derivatives of the novel heterocyclic parent systems imidazolo[1,2-a]thiopyrano[4′,3′:4,5]thieno[2,3-d]-pyrimidine (B) and thiopyrano[4′,3′:4,5]thieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine (C) have been synthesized by fusing pyrimidine moieties to 2-amino-4,7-dihydro-5H-thieno[2,3-c]thiopyran-3-car-boxylic acid ethyl ester (1) and -3-carbonitrile (10), followed by cyclization reactions of the title intermediates A thus obtained.

Full text of DOI:10.1135/cccc19960147

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147
FUSION REACTIONS OF N-HETEROCYCLIC MOIETIES
TO THIOPYRANO[4′,3′:4,5]THIENO[2,3-d]PYRIMIDINES
a
b
b
Essam K. AHMED , Johannes FROHLICH and Fritz SAUTER
a Chemistry Department,
Faculty of Science, Minia University, El-Minia, Egypt
b Institute of Organic Chemistry,
Technical University Vienna, Getreidemarkt 9, A-1060 Vienna, Austria
Received July 21, 1995
Accepted September 17, 1995
Dedicated to Professor K. Gewald, TU Dresden, on the occasion of his 65th birthday.
Derivatives of the novel heterocyclic parent systems imidazolo[1,2-a]thiopyrano[4′,3′:4,5]thieno[2,3-d]-
pyrimidine (B) and thiopyrano[4′,3′:4,5]thieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine (C) have been
synthesized by fusing pyrimidine moieties to 2-amino-4,7-dihydro-5H-thieno[2,3-c]thiopyran-3-car-
boxylic acid ethyl ester (1) and -3-carbonitrile (10), followed by cyclization reactions of the title in-
termediates A thus obtained.
Key words: Annelation reactions; Thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidines.
In three papers published recently1–3 we reported on annelation reactions of pyrimidine
moieties at (hetero)aromatic systems, on some ways to synthesize products derived
from the thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidine system (A) and on various fusion
reactions to this system carried out to approach novel tetracyclic systems. The present
paper is following that line of research by reporting on a new series of linear and
angular fusion reactions to this system, in which imidazole and 1,2,4-triazole moieties
were annelated, yielding derivatives of the novel tetracyclic ring systems B and C.
N
N
N
N
N
S
S
S
S
N
S
N
N
S
N
A
B
C
An approach to system B started from 2-amino-4,7-dihydro-5H-thieno[2,3-c]thio-
pyran-3-carboxylic acid ethyl ester4 (1), which was converted into 5,8-dihydro-2-
methylthio-4-oxo-4H-thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidin-4-one (7). On reaction
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Ahmed, Frohlich, Sauter:
with hydrazine hydrate the methylthioester 7 yielded the target N-aminolactam 9. As
depicted in Scheme 1, the key intermediate 7 can be obtained – in addition to the
BMMA-method (utilization of bis(methylthio)methylenamino reagents) which we published
recently1 – by one of the following two sequences: (i) preparation of 2-thioxo-1,5,6,8-
tetrahydro-2H-thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidin-4(3H)-one (5) according to published
procedures2 (i.e. by reaction with ethoxycarbonylisothiocyanate and ensuing cycliza-
tion), followed by S-methylation to 6 and N-substitution, or (ii) reaction of 1 with ethyl
isothiocyanatoacetate to 2, followed by cyclization to 3 and subsequent methylation.
The desired tetracyclic 1-amino-3,6,7,9-tetrahydro-5H-imidazo[1,2-a]thiopyrano-
[4′,3′:4,5]thieno[2,3-d]pyrimidin-2(1H),5-dione (9) can be obtained either by reaction
of the methylthio derivative 7 with hydrazine hydrate (as mentioned above), or alterna-
tively by converting the thioxo-functionality of 3 by POCl3 into the replaceable chloro
substituent of 8 and by final cyclization of 8 with hydrazine hydrate.
Approaches to derivatives of parent system C were started from 2-amino-4,7-dihy-
dro-5H-thieno[2,3-c]thiopyran-3-carbonitrile (10) obtained according to the literature5.
The nitrile 10 upon consecutive reactions with orthoformate (leading to 11) and hydra-
zine hydrate gave the key intermediate 12 (Scheme 2).
Reactions of compound 12 with ortho esters, trichloroacetonitrile and chloroacetyl
chloride according to published methods6 yielded the compounds 13, 14 and 15, respec-
tively, all three of them derived from the new parent system C.
EXPERIMENTAL
Melting points were determined on a Kofler melting point apparatus and are uncorrected. Elemental
analyses were performed at the Microanalytical Laboratory, Institute of Physical Chemistry, Univer-
1
sity of Vienna (Mag. J. Theiner). 13C and H NMR spectra (δ, ppm) were measured on a Bruker AC
200 spectrometer (1H at 200.13 MHz, 13C at 50.32 MHz frequency) 5 mm dual 1H/13C- VT probe
~
head at 300 K; solvent: (CD3)2SO and CDCl3, respectively; internal standard TMS. IR spectra (ν, cm–1)
were recorded on a Shimadzu 470 Spectrophotometer in KBr pellets.
Ethyl 2-[(Ethoxycarbonylmethylaminothiocarbonyl)amino]-4,7-dihydro-5H-thieno[2,3-c]thiopyran-3-
carboxylate (2)
A solution of ethoxycarbonylmethylisothiocyanate (0.73 g, 0.005 mol) was added to a stirred solution
of compound 1 (ref.4, 1.21 g, 0.0049 mol) in absolute ethanol (10 ml). The whole mixture was heated
under reflux for 2 h. On cooling, the separated solid product was collected by filtration, dried and
recrystallized from ethanol. Yield: 1.6 g (84%) of compound 2 as white crystals, m.p. 163–165 °C.
For C15H20N2O4S3 (388.5) calculated: 46.36% C, 5.18% H, 7.21 N; found: 46.29% C, 4.97% H,
1
7.18% N. IR spectrum: 1 500, 1 580, 1 660, 1 720, 2 980, 2 990, 3 100, 3 300. H NMR spectrum
((CD3)2SO): 1.20 t, 3 H (COOCH2CH3); 1.30 t, 3 H (COOCH2CH3); 2.85 t, 2 H (H-4); 2.95 t, 2 H
(H-5); 3.70 s, 2 H (H-7); 4.15 q, 2 H (COOCH2CH3); 4.20–4.40 m, 4 H (COOCH2CH3, CH2COO);
9.90 s, 1 H (NH); 11.60 s, 1 H (NH). 13C NMR spectrum ((CD3)2SO): 14.02 q (COOCH2CH3),
14.03 q (COOCH2CH3), 24.14 t (C-4), 25.43 t (C-5), 27.64 t (C-7), 45.45 t (NHCH2), 60.48 t
(COOCH2CH3), 60.56 t (COOCH2CH3), 111.66 s (C-3), 121.63 s (C-7a), 129.50 s (C-3a), 149.10 s
(CO), 165.43 s (CO), 168.99 s (C-2), 178.62 s (C=S).
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Ahmed, Frohlich, Sauter:
Ethyl 4-Oxo-2-thioxo-1,5,6,8-tetrahydro-2H-thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidine-3(4H)-acetate (3)
Compound 2 (1 g, 0.0025 mol) was dissolved in a solution of sodium ethoxide (from 0.06 g, 0.0025 mol,
sodium and 10 ml absolute ethanol) and the solution was stirred at room temperature for 5 min. The
sodium salt of compound 3 was collected, then dissolved in water and neutralized (to pH 4) with
hydrochloric acid. The separated product was collected by filtration, washed with ethanol, dried and
recystallized from ethanol. Yield: 0.75 g (85%) of compound 3 as white crystals, m.p. 238–240 °C.
For C13H14N2O3S3 (342.4) calculated: 45.59% C, 4.12% H, 8.18% N; found: 44.93% C, 4.03% H,
1
8.07% N. IR spectrum: 1 400, 1 460, 1 500, 1 640, 1 720, 2 990, 3 000, 3 400. H NMR spectrum
CN
S
S
NH
2
13
a
R
10
H
b
CH
3
CH(OEt)
R
N
3
N
CN
CR(OEt)
N
N
N
3
S
S
S
S
R = H, CH
3
S
N
OEt
S
N
13
11
NH NH .H O
2
2
2
CCl
N
3
NH
N
NH
2
N
CCl CN
3
S
S
N
S
N
12
14
CH Cl
2
N
N
ClCOCH Cl
2
S
N
15
SCHEME 2
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151
((CD3)2SO): 1.20 t, 3 H (COOCH2CH3); 2.85 t, 2 H (H-5); 3.00 t, 2 H (H-6); 3.80 s, 2 H (H-8); 4.10 q,
2 H (COOCH2CH3); 5.10 s, 2 H (CH2COO); 13.80 s, 1 H (NH). 13C NMR spectrum ((CD3)2SO):
14.92 q (COOCH2CH3), 24.05 t (C-5), 24.46 t (C-6), 26.91 t (C-8), 60.54 t (NCH2), 61.73 t
(COOCH2CH3), 116.63 s (C-4a), 124.02 s (C-4b), 130.61 s (C-8a), 149.51 s (C-9a), 156.95 s (C-4),
173.11 s (C-2), 187.75 (CO ester).
Ethyl 2-[(Ethoxycarbonylaminothiocarbonyl)amino]-4,7-dihydro-5H-thieno[2,3-c]thiopyrane-3-carboxy-
late (4)
A solution of ethoxycarbonylisothiocyanate (prepared by mixing ethylchloroformate (1.08 g, 0.01
mol) in dry acetone with ammonium thiocyanate (0.76 g, 0.01 mol) and heating in a water bath for
20 min) was added to a stirred solution of compound 1 (2.4 g, 0.01 mol) in acetone (30 ml). The
whole mixture was heated under reflux in a water bath for 2 h, then evaporated in vacuo. The re-
maining product was triturated with ethanol, then collected by filtration, dried and recrystallized from
ethanol. Yield: 2.6 g (70%) of compound 4 as yellow crystals, m.p. 175–176 °C. For C14H18N2O4S3
1
(374.5) calculated: 44.89% C, 4.84% H, 7.48% N; found: 45.03% C, 4.56% H, 7.63% N. H NMR
spectrum (CDCl3): 1.30 m, 6 H (2 × COOCH2CH3); 2.90 t, 2 H (H-4); 3.20 t, 2 H (H-5); 3.70 s, 2 H
(H-7); 4.40 m, 4 H (2 × COOCH2CH3); 8.10 s, 1 H (NH); 14.10 s, 1 H (NH). 13C NMR spectrum
(CDCl3): 14.12 q (OCH2CH3), 14.22 q (OCH2CH3), 25.13 t (C-4), 26.17 t (C-5), 27.92 s (C-7),
60.83 t (OCH2CH3), 62.94 t (OCH2CH3), 116.16 s (C-3), 123.78 s (C-7a), 131.07 s (C-3a), 146.84 s
(COOCH2CH3), 151.21 s (COOCH2CH3), 164.99 s (C-2), 173.39 s (C=S).
2-Thioxo-1,5,6,8-tetrahydro-2H-thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidin-4(3H)-one (5)
Compound 4 (3.7 g, 0.0098 mol) was dissolved in a solution of sodium ethoxide (from 0.23 g sodium
and 15 ml absolute ethanol) and the solution was heated under reflux for 30 min. The solvent was
evaporated in vacuo, some water was added to the residue, and the mixture neutralized (to pH 4)
with hydrochloric acid. The separated product was collected and crystallized from dimethylforma-
mide–toluene. Yield: 1.8 g (72%) of the product 5 as white crystals, m.p. 250 °C (dec.). For
C9H8N2OS3 (256.4) calculated: 42.16% C, 3.14% H, 10.93% N; found: 42.32% C, 3.34% H, 11.32% N.
1H NMR spectrum ((CD3)2SO): 2.90 t, 2 H (H-5); 3.10 t, 2 H (H-6); 3.70 s, 2 H (H-8); 12.30 s, 1 H
(NH); 13.30 s, 1 H (NH). 13C NMR spectrum ((CD3)2SO): 24.00 t (C-5), 24.43 t (C-6), 26.98 t (C-8),
116.54 s (C-4a), 124.47 s (C-4b), 130.47 s (C-8a), 149.38 s (C-9a), 156.83 s (C-4), 172.88 s (C-2).
2-Methylthio-3,5,6,8-tetrahydro-4H-thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidin-4-one (6)
To a suspension of 5 (0.5 g, 0.0019 mol) in acetone (20 ml) was added anhydrous potassium carbo-
nate (0.25 g) followed by methyl iodide (0.38 g, 0.0026 mol). The reaction mixture was stirred at
room temperature for 1 h and poured into water. The solid product which precipitated was collected
by filtration, dried and recrystallized from dimethylformamide. Yield: 0.42 g (80%) of compound 6
as white crystals, m.p. 285–287 °C. For C10H10N2OS3 (270.4) calculated: 44.41% C, 3.72% H,
10.36% N; found: 44.19% C, 3.60% H, 10.15% N. 1H NMR spectrum ((CD3)2SO): 2.55 s, 3 H
(SCH3); 2.90 t, 2 H (H-5); 3.10 t, 2 H (H-6); 3.90 s, 2 H (H-8); 12.60 s, 1 H (NH).
Ethyl 5,8-Dihydro-2-(methylthio)-4-oxo-4H-thiopyrano[4′,3′:4,5]thieno[2,3-d]-
pyrimidine-3(6H)-acetate (7)
Method A. A solution of 3 (0.68 g, 0.002 mol) in 1 M aqueous sodium hydroxide (1.5 ml) was
treated with methyl iodide (0.57 g, 0.004 mol) and the mixture was stirred at 25 °C. The methylthio
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Ahmed, Frohlich, Sauter:
compound 7 started to crystallize almost immediately. After 2 h, it was filtered off, washed with
water, dried and crystallized from ethanol. Yield: 0.5 g (71%) of compound 7 as colorless crystals,
m.p. 233 °C. For C14H16N2O3S3 (356.5) calculated: 47.16% C, 4.52% H, 7.86% N; found: 46.91% C,
4.31% H, 7.68% N. IR spectrum: 1 490, 1 510, 1 680, 1 720, 2 990, 3 000. 1H NMR spectrum
(CDCl3): 1.20 t, 3 H (COOCH2CH3); 2.60 s, 3 H (SCH3); 2.90 t, 2 H (H-5); 3.30 t, 2 H (H-6); 3.80 s,
2 H (H-8); 4.20 q, 2 H (COOCH2CH3); 4.90 s, 2 H (NCH2COO). 13C NMR spectrum ((CD3)2SO):
13.99 q (SCH3), 14.85 q (COOCH2CH3), 24.14 t (C-4), 25.32 t (C-5), 27.59 t (C-7), 60.43 t (NCH2),
61.52 t (COOCH2CH3), 111.46 s (C-4a), 122.51 s (C-4b), 129.91 s (C-8a), 145.54 s (C-9a), 164.64 s
(C-2), 167.39 s (C-4), 187.73 s (CO ester).
Method B. To a solution of 6 (1 g, 0.0036 mol) in dimethylformamide (10 ml) were added anhy-
drous potassium carbonate (0.65 g, 0.0047 mol) and ethyl bromoacetate (0.8 g, 0.0047 mol). After
stirring at 60 °C for 4 h, the mixture was poured into water, acidified with 2 M hydrochloric acid and
extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and
evaporated. The residue was purified using column chromatography (ethanol–toluene 1 : 5). Yield:
0.8 g (61%) of compound 7 as white crystals, m.p. 233 °C. The compound is identical with the com-
pound obtained above.
Ethyl 2-Chloro-5,8-dihydro-4-oxo-4H-thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidine-3(6H)-acetate (8)
A suspension of 3 (1 g, 0.0025 mol) in POCl3 (15 ml) was refluxed at 120 °C for 6 h. The reaction
mixture became clear. Excess POCl3 was distilled off under reduced pressure. The reaction mixture
was cooled and poured into ice/water, the solid product was separated, filtered and passed through a
column of silica gel. Elution with toluene–methanol (5 : 1) yielded 0.6 g (68%) of compound 8, m.p.
147–149 °C. For C13H13ClN2O3S2 (344.8) calculated: 45.27% C, 3.79% H, 8.12% N; found: 45.57%
1
C, 3.99% H, 7.87% N. H NMR spectrum ((CD3)2SO): 1.20 t, 3 H (COOCH2CH3); 2.90 t, 2 H (H-
5); 3.20 t, 2 H (H-6); 3.80 s, 2 H (H-8); 4.10 q, 2 H (COOCH2CH3); 4.90 s, 2 H (CH2COO).
1-Amino-3,6,7,9-tetrahydro-5H-imidazolo[1,2-a]thiopyrano[4′,3′:4,5]thieno[2,3-d]-
pyrimidine-2(1H),5-dione (9)
Method A. A suspension of 7 (0.4 g, 0.001 mol) in 99% hydrazine hydrate (4 ml) was refluxed
gently in absolute ethanol (10 ml). The insoluble solid went into solution within 10 min. After 30 min,
when the solid product started to separate, heating was discontinued and the reaction mixture was
allowed to cool to room temperature. The solid was filtered, washed with water and ethanol, dried
and recrystallized from dimethylformamide. Yield: 0.25 g (76%) of compound 9 as white crystals,
m.p. >310 °C. For C11H10N4O2S2 (294.3) calculated: 44.88% C, 3.42% H, 19.03% N; found: 44.63% C,
1
3.21% H, 18.91 N. H NMR spectrum ((CD3)2SO): 2.90 t, 2 H (H-6); 3.10 t, 2 H (H-7); 3.80 s, 2 H
(NH2); 5.20 s, 2H (H-3).
Method B. Compound 8 (0.4 g, 0.001 mol) and 99% hydrazine hydrate (2 ml) in ethanol (10 ml) were
heated under reflux for 20 min. The reaction mixture was allowed to cool to room temperature. The
separated solid product was collected by filtration, washed with ethanol, dried and recrystallized from
dimethylformamide. Yield: 0.28 g (76%) of compound 9 as white crystals, m.p. >310 °C.
2-[(Ethoxymethylene)amino]-4,7-dihydro-5H-thieno[2,3-c]thiopyran-3-carbonitrile (11)
A mixture of 10 (ref.4, 0.5 g, 0.0025 mol) and triethyl orthoformate (20 ml) was refluxed for 4 h.
The excess triethyl orthoformate was removed under reduced pressure and the resulting solid product
was collected by filtration, dried and recrystallized from methanol. Yield: 0.6 g (94%) of compound
11 as pale yellow crystals, m.p. 89–90 °C. For C11H12N2OS2 (252.3) calculated: 52.35% C, 4.12% H,
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1
11.10% N; found: 52.18% C, 4.12% H, 10.95% N. IR spectrum: 1 610, 2 200, 2 800, 2 990. H NMR
spectrum (CDCl3): 1.30 t, 3 H (OCH2CH3); 2.90 s, 4 H (H-4, H-5); 3.60 s, 2 H (H-7); 4.40 q, 2 H
(OCH2CH3); 7.90 s, 1 H (N=CH).
3-Amino-3,5,6,8-tetrahydro-4H-thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidine-4-imine (12)
To a solution of 11 (0.8 g, 0.003 mol) in ethanol (20 ml) was added a solution of hydrazine hydrate
(4 ml) and the mixture was stirred at room temperature for 45 min. The solid product was collected
by filtration, dried and recrystallized from ethanol. Yield: 0.52 g (69%) of compound 12 as colorless
crystals, m.p. 178–180 °C. For C9H10N4S2 (238.3) calculated: 45.35% C, 4.22% H, 23.51% N; found:
45.59% C, 3.99% H, 23.30% N. IR spectrum: 1 410, 1 460, 1 600, 2 990, 3 000, 3 150, 3 250, 3 400.
1H NMR spectrum ((CD3)2SO): 2.90 t, 2 H (H-5); 3.20 t, 2 H (H-6); 3.90 s, 2 H (H-8); 5.60 s, 2 H
(NH2); 7.10 s, 1 H (NH); 7.90 s, 1 H (H-2). 13C NMR spectrum ((CD3)2SO): 24.87 t (C-5), 25.02 t
(C-6), 28.36 s (C-8), 120.51 s (C-4a), 127.75 s (C-4b), 130.87 s (C-8a), 148.35 s (C-9a), 151.41 s
(C-2), 154.68 s (C-4).
10,11-Dihydro-8H-thiopyrano[4′,3′:4,5]thieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine (13a)
Compound 12 (0.3 g, 0.0012 mol) was refluxed with triethyl orthoformate (10 ml) for 4 h. The ex-
cess triethyl orthoformate was removed under reduced pressure and the resulting solid product was
collected by filtration, dried and recrystallized from ethanol. Yield: 0.23 g (74%) of compound 13a
as yellow crystals, m.p. 191–193 °C. For C10H8N4S2 (248.3) calculated: 48.36% C, 3.24% H, 22.56%
1
N; found: 48.10% C, 3.25% H, 22.40% N. IR spectrum: 1 540, 1 620, 2 990, 3 050. H NMR spec-
trum (CDCl3): 3.10 t, 2 H (H-11); 3.60 t, 2 H (H-10); 3.90 s, 2 H (H-8); 8.30 s, 1 H (H-2); 9.20 s,
1 H (H-5).
2-Methyl-10,11-dihydro-8H-thiopyrano[4′,3′:4,5]thieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine (13b)
Compound 12 (0.3 g, 0.001 mol) and triethyl orthoacetate (8 ml) were treated as described for the
preparation of compound 13a. The yield of the recrystallized compound 13b was 68%, m.p. 228–230 °C.
For C11H10N4S2 (262.3) calculated: 50.35% C, 3.84% H, 21.35% N; found: 49.99% C, 3.60% H,
1
21.18% N. H NMR spectrum ((CD3)2SO): 2.55 s, 3 H (CH3); 3.00 t, 2 H (H-11); 3.30 t, 2 H (H-10);
4.10 s, 2 H (H-8); 9.50 s, 1 H (H-5).
2-Trichloromethyl-10,11-dihydro-8H-thiopyrano[4′,3′:4,5]thieno[3,2-e][1,2,4]triazolo[1,5-c]-
pyrimidine (14)
A mixture of 12 (0.3 g, 0.0012 mol) and trichloroacetonitrile (5 ml) was heated under reflux for 20 h.
After cooling, the solid product was collected by filtration, washed with a small amount of ethanol
and recrystallized from ethanol. Yield: 0.3 g (65%) of compound 14 as colorless crystals, m.p. 250–252 °C
(dec.). For C11H7Cl3N4S2 (365.7) calculated: 36.12% C, 1.92% H, 15.32% N; found: 36.32% C,
1
1.99% H, 15.51% N. H NMR spectrum ((CD3)2SO): 2.90 t, 2 H (H-11); 3.20 t, 2 H (H-10); 4.00 s,
2 H (H-8); 8.70 s, 1 H (H-5).
2-Chloromethyl-10,11-dihydro-8H-thiopyrano[4′,3′:4,5]thieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine (15)
Chloroacetyl chloride (0.3 g, 0.0026 mol) was added dropwise under stirring to a solution of 12 (0.3 g,
0.0012 mol) in dimethylformamide (6 ml). Then the reaction mixture was heated on a steam bath for
2 h and – after cooling – poured into ice/water (50 ml). The solid product was collected by filtration,
washed with water and recrystallized from ethanol. Yield: 0.3 g (81%) of compound 15 as colorless
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Ahmed, Fröhlich, Sauter:
crystals, m.p. 206–208 °C. For C11H9ClN4S2 (296.8) calculated: 44.51% C, 3.05% H, 18.87% N;
1
found: 44.31% C, 2.89% H, 18.69% N. H NMR spectrum ((CD3)2SO): 3.00 t, 2 H (H-11); 3.30 t, 2 H
(H-10); 4.10 s, 2 H (H-8); 5.00 s, 2 H (CH2Cl); 9.60 s, 1 H (H-5).
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Ahmed, Frohlich, Sauter:
crystals, m.p. 206–208 °C. For C11H9ClN4S2 (296.8) calculated: 44.51% C, 3.05% H, 18.87% N;
1
found: 44.31% C, 2.89% H, 18.69% N. H NMR spectrum ((CD3)2SO): 3.00 t, 2 H (H-11); 3.30 t, 2 H
(H-10); 4.10 s, 2 H (H-8); 5.00 s, 2 H (CH2Cl); 9.60 s, 1 H (H-5).
REFERENCES
1. Sauter F., Frohlich J., Blasl K., Gewald K.: Heterocycles 40, 851 (1995); and references therein.
2. Sauter F., Frohlich J., Ahmed E. K.: Monatsh. Chem. 126, 945 (1995).
3. Ahmed E. K.: Monatsh. Chem. 126, 953 (1995).
4. Noravyan A. S., Oganisyan A. S., Basentsyank E., Vartanvan S. A.: Arm. Khim. Zh. 36, 108
(1983); Chem. Abstr. 99, 22418 (1983).
5. Elslager E. F., Jacob P., Werbel L. M.: J. Heterocycl. Chem. 9, 775 (1972).
6. Liu K., Shih B., Chern J.: J. Heterocycl. Chem. 26, 457 (1989).
Collect. Czech. Chem. Commun. (Vol. 61) (1996)