Palladium-catalyzed cross-coupling of 5-acyl and 5-formyl-1,2,4-triazines and their derivatives with heteroaromatic tin compounds

Article abstract of DOI:10.1016/j.tet.2014.04.094

The synthesis of novel mono- and di(substituted)-1,2,4-triazine derivatives containing thiophene and furan rings are described. Heteroaromatic rings were provided using palladium-catalyzed cross-coupling reaction between 3-alkylsulfanyl-5-acyl-1,2,4-triaz

Full text of DOI:10.1016/j.tet.2014.04.094

Accepted Manuscript
Palladium-catalyzed cross-coupling of 5-acyl and 5-formyl-1,2,4-triazines and their
derivatives with heteroaromatic tin compounds
Danuta Branowska, Ewa Olender, Andrzej Rykowski
PII:
S0040-4020(14)00640-1
10.1016/j.tet.2014.04.094
TET 25544
DOI:
Reference:
To appear in: Tetrahedron
Received Date: 22 July 2013
Revised Date: 14 April 2014
Accepted Date: 29 April 2014
Please cite this article as: Branowska D, Olender E, Rykowski A, Palladium-catalyzed cross-coupling of
5-acyl and 5-formyl-1,2,4-triazines and their derivatives with heteroaromatic tin compounds, Tetrahedron
(2014), doi: 10.1016/j.tet.2014.04.094.
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Palladium-catalyzed cross-coupling of 5-acyl
and 5-formyl-1,2,4-triazines and their
derivatives with heteroaromatic tin
compounds.
Leave this area blank for abstract info.
Danuta Branowskaa*, Ewa Olendera and Andrzej Rykowskia
aDepartment of Chemistry, Siedlce University, 3 Maja 54, 08-110 Siedlce, Poland
N
N
N
N
R1 - ketones
methoxyimines
N
N
N
N
and/or
N
X
X
X
nitriles
R1
R2 - methylsulfanyl
isopropylsulfanyl
R2
R1
X = S or O

1
ACCEPTED MANUSCRIPT
Tetrahedron
journal homepage: www.elsevier.com
Palladium-catalyzed cross-coupling of 5-acyl and 5-formyl-1,2,4-triazines and their
derivatives with heteroaromatic tin compounds.
Danuta Branowskaa, , Ewa Olendera and Andrzej Rykowskia
aDepartment of Chemistry, Siedlce University, 3 Maja 54, 08-110 Siedlce, Poland
ARTICLE INFO
ABSTRACT
Article history:
Received
Received in revised form
Accepted
The synthesis of novel mono- and di(substituted)-1,2,4-triazine derivatives containing
thiophene and furan rings are described. Heteroaromatic rings were provided using palladium-
catalyzed cross-coupling reaction between 3-alkylsulfanyl-5-acyl-1,2,4-triazines or 5-cyano-3-
alkylsulfanyl-1,2,4-triazines and heteroaromatic tin compounds. New compounds bearing
masked acyl groups were also obtained. These reactions were optimized to determine the scope
and limitations of this methodology and were used for preparation of oligothiophenes bearing
terminal heterocyclic ring.
Available online
Keywords:
1,2,4-Triazine
2009 Elsevier Ltd. All rights reserved
.
Stille cross-coupling reaction
3- or 3,5-biheteroaryl 1,2,4-triazine
leaving group
1. Introduction
(tri-n-butylstannyl)thiophene or 2-(tri-n-butylstannyl)furan to
provide rapid access to 5-acyl-3-heteroaryl-1,2,4-triazines 2a-f
(Scheme 1).5 According to the literature many aryls and
heteroarylstannanes were coupled in excellent yields with 3-
methylsulfanyl-1,2,4-triazine (1) in the presence of CuBr•Me2S
and Pd(PPh3)4 in refluxing THF.6 Surprisingly, to our knowledge
such reactions have never been studied with the 5-substituted 3-
methylsulfanyl-1,2,4-triazines. Herein we present a full account
of this study5 and of our recent findings on the synthesis of
conducting thiophenes containing the 1,2,4-triazine ring. The
latter or oligothiophenes bearing terminal heterocyclic ring are
widely used to prepare conjugated polymers by chemical or
electrochemical oxidative coupling reactions and have been
found applications in optoelectrical devices.7
1,2,4-Triazines are important heterocyclic ring systems which
are present in numerous biologically active compounds and are
widely used in organic synthesis as azadiene equivalent in the
inverse electron demand Diels-Alder reactions.1 The oximes of
an 5-acyl and 5-formyl-1,2,4-triazines, directly accessible via
SNH reaction between C-5 unsubstituted 1,2,4-triazines and
nitronate ions, have shown considerable synthetic utility for a
medicinal chemistry studies.2 While the regioselective
nucleophilic formylation or acylation of 3-R-1,2,4-triazines (R =
alkyl, aryl, SR, OR, NR2) by nitronates can be easily
accomplished,3,4 the same reactions of 1,2,4-triazines bearing
heteroaromatic substituent at C-3 (R = furyl or thienyl) have been
less successfully performed. Our studies have shown that the
reactions of 3-(thiophen-2-yl)-1,2,4-triazine (4b) with nitroethane
under basic conditions are relatively low yielding and
complicated by uncharacterized side products. Considering the
sluggish reactivity of these 3-heteroaromatic-1,2,4-triazines
towards nitronate ions, we thought it would be interesting to
utilize the Stille-type cross-coupling reaction between readily
available 5-acyl-3-methylsulfanyl-1,2,4-triazines (1a-c) and 2-
Our initial attempts to couple 5-acetyl-3-methylsulfanyl-1,2,4-
triazine
(1a)
with
commercially
available
2-(tri-n-
butylstannyl)thiophene using the conditions mentioned above
provided two products: the desired 5-acetyl-3-(thiophen-2-yl)-
1,2,4-triazine (2a) (12%) and rearranged product i.e. 3-(thiophen-
2-yl)-5-(pyridin-3-yl)-1,2,4-triazine (3a) (42%) (Scheme 1).
———
Corresponding author. Tel.: +48-25-643-1128; fax: +48-25-643-1130; e-mail: dankab@uph.edu.pl

2
Tetrahedron
X
N
SnBu
ACCEPTED MANUSCRIPT
3
N
R
N
N
N
N
THF
N
X
N
X
+
RCH2
RCH2
X
R1
N
Pd(PPh3)4
CuBr Me2S
N
RCH2
O
O
1a-c
2a-f
O
3a-f
R = H, CH3(CH2)n- ; n = 0-2
-N2
-H2O
R1 = SCH3
X = O, S
O
N
N
N
2a-f
CH2R
N
N
R
N
HO
N
X
N
X
N
OH
CH2R
2'a-f
3'a-f
X
Scheme 1. The Stille cross-coupling reaction of 5-acyl-3-alkylsulfanyl-1,2,4-triazines 1a-c.
A similar reactivity pattern was observed in the reactions of 5-
pyridyltriazine 3a in better yield than compound 2h having less
electron donating methylsulfanyl group.
propanoyl- (1b) and 5-butanoyl-3-methylsulfanyl-1,2,4-triazine
(1c) with 2-(tri-n-butylstannyl)thiophene and the results obtained
are summarized in Table 1. Extending these studies by using 2-
N
(tri-n-butylstannyl)furan
in
place
of
2-(tri-n-
N
N
Pd(PPh3)4
N
butylstannyl)thiophene showed the generality of this process,
however with increasing steric bulk of the alkyl chain both
conversions decreased.
N
R
H3C
THF
N
R
H3C
N
R
6.4 - 60%
O
O
3a, g-h
Table 1. Yields of Stille coupling reaction 1,2,4-triazine
ketones 1.
2a R = Th
2g R = Ph
2h R = SCH3
Comp.
2 - X
2 [%]
3 [%]
Scheme 2. Palladium catalyzed Diels-Alder reaction of 5-acyl-3-substituted-
1,2,4-triazines 2a, g-h.
1a (R = H)
2a - S
2b - O
2c - S
2d - O
2e - S
2f - O
2a - 12
2b - 21
2c - 17
2d - 42
2e - 16
2f - 11
3a – 40
3b – 26
3c – 27
3d – 13
3e – 5
1a (R = H)
1b (R = CH3)
1b (R = CH3)
1c (R = C2H5)
1c (R = C2H5)
Table 2. Yields of the pyridyltriazine derivatives 3a, g-h
obtained in Diels-Alder reaction.
Comp.
Yield of 3 [%]
Yield of the recovered
substrate 2 [%]
3f – 2
2a R = Th
2g R = Ph
2h R = SCH3
60
24
6.4
36
33
38
The rearranged products 3a-f were formed via a tandem Stille
cross-coupling/Diels-Alder/retro Diels-Alder reaction.
A
Replacement of 5-acetyl-3-methylsulfanyl-1,2,4-triazine 1a by
1d containing methoxyimine group8 at C-5, which is masked
ketone function, should prevent the enolization and competitive
Diels-Alder reaction of 1d in the presence of palladium catalyst.
plausible mechanism of this ring transformation including the
keto-enol tautomerism of an acyl group in 2a-f catalyzed by
metal ions is outlined in Scheme 1. The existence of the enol
form in 2’a-f was supported by spectroscopic experiments, X-ray
and in particular by extensive ab initio calculations.5
Consequently, in the primary step of the reaction not the carbonyl
group itself but tautomeric enol forms 2’a-f act as an electron-
rich dienophiles and undergo Diels-Alder/retro Diels-Alder
reaction with electron-poor unchanged 5-acyl-1,2,4-triazines 2a-f
giving the adducts 3’a-f. After elimination of water and nitrogen
from the adducts the corresponding pyridyltriazines 3a-f were
obtained. For a further proof of this mechanism, we determined
the role of the palladium catalyst on the enolization and Diels-
Alder reaction of 5-acetyl-3-R-1,2,4-triazines 2a and 2g-h
bearing various substituents at C-3 (Scheme 2, Table 2).
O
SnBu3
THF
N
N
N
N
N
R
H3CON
N
SCH3
Pd(PPh3)4
X
CH3
CuBr Me2S
61 - 90 %
1d
4a X = O, R = methoxyiminoethyl
4b X = S, R = H
NBS/DMF
45 - 48 %
N
N
X
N
SnBu3
N
N
R
R
N
X
Pd(PPh3)THF
4
X
X
In the absence of palladium catalyst ring-transformation products
3a, g-h were not formed. However, the 5-acetyl-1,2,4-triazines
2a, g-h refluxed in THF for 24 h in the presence of 5 mol % of
Pd(PPh3)4 afforded the expected pyridyltriazines 3a, g-h. From
the data presented in Table 2 it is clear that reaction of 5-acetyl-
3-(thiophen-2-yl)-1,2,4-triazine 2a gives the corresponding
26 - 94 %
Br
5a X = O, R = methoxyiminoethyl
5b X = S, R = H
6a X = O, R = methoxyiminoethyl
6b X = S, R = H
Scheme 3. Synthesis of 5-substituted and 5-unsubstituted 1,2,4-
triazine oligomers 6a and 6b

3
When we allowed 1d to react with 2-(tri-n-butylstannyl)furane in
palladium complex which subsequently converts into
substituted products 12 and 14.
ACCEPTED MANUSCRIPT
the presence of CuBr•Me2S and Pd(PPh3)4 in refluxing THF, we
found that the desired 3-(furan-2-yl)-5-methoxyimino-1,2,4-
triazine 4a was formed in 61% yield, as the only reaction product
(Scheme 3). This result clearly shows that under the conditions
mentioned above compound 1d, with protected keto group,
undergoes Stille reaction exclusively. Based on this last result,
we examined the preparation of the oligomers 6a-b bearing
terminal 1,2,4-triazine ring (Scheme 3).
N
N
N
N
a
X
N
Ph
28 %
NC
N
Ph
12
11
Ph
Ph
N
N
Ph
Ph
N
N
N
N
a
X
25 %
CN
The synthesis of oligomer 6a began with the preparation of the
corresponding bromo compound 5a by bromination of 4a with
NBS in DMF at room temperature. The product 5a as yellow
solid was obtained in satisfactory yield. Coupling 5a with 2-(tri-
n-butylstannyl)furan under mentioned above conditions without
of CuBr•Me2S yielded the required oligomer 6a. Similarly,
analogous sequence of reactions was applied to the synthesis of
oligomer 3-(2,2’-bithiophen-5yl)-1,2,4-triazine (6b) starting from
easily available 3-(thiophen-2-yl)-1,2,4-triazine (4b)6. The latter
was obtained via this route in 94 % yield (Scheme 3).
13
a) 2-(tri-n-butylstannyl)furan, Pd(PPh3)4, THF
14
Scheme 5. The reactivity of the cyano group of the 1,2,4-triazine derivatives
11, 13 in the Stille coupling procedure.
2. Conclusion
In searching an effective route to 3,5-di(heteroaryl)-1,2,4-
triazines we have explored the Stille type reaction between 5-
In conclusion, we have presented the direct introduction of five-
membered heterocyclic rings into triazine nucleus by Stille
coupling starting from 3-alkylsulfanyl-1,2,4-triazines bearing at
C-5 the acyl, methoxyimine or cyano substituents. Utility of
these compounds in the synthesis of oligthiophenes or
oligofurans bearing heterocyclic ring are currently in progress.
cyano-3-isopropylsulfanyl-1,2,4-triazine
7
and
2-(tri-n-
butylstannyl)thiophene or 2-(tri-n-butylstannyl)furan (Scheme 4).
It is well known that cyano substituent9 at the 5-position of 1,2,4-
triazine ring is an efficient leaving group10 in reactions with
nucleophiles.3 To the best of our knowledge, the cyano
substituent has never been used as a leaving group in the Stille
coupling reaction.11
3. Experimental section
3.1. General information
N
N
N
N
N
+
X
X
X
N
a
NC
N
N
9a,b
12 - 24 %
1
Melting points are uncorrected. H and 13C NMR spectra were
8a,b
46 - 50 %
NC
N
SCH(CH3)2
determined at 400 and 100 MHz respectively on Varian Gemini
spectrometer. Chemical shifts (δ) are given in parts per million
and coupling constants are given as absolute values expressed in
Hertz. Mass spectra were obtained using AMD 604 (AMD
Intectra GmbH, Germany) and GC/MS QP 5050 Shimadzu (30 m
× 0.25 mm ID-BPX 5 0.25 mm) spectrometers. Elemental
analyses were recorded on Perkin-Elmer 2400-CHN analyzer and
the results for indicated elements were within 0.3% of the
calculated values. Thin layer chromatography (TLC) was carried
out on aluminium sheets percolated with silica gel 60
F254(Merck). Column chromatography separations were
performed using Merck Kieselgel 60 (0.040-0.060 mm). Solvents
were dried and distilled according to standard procedures. All
reagents were purchased from Aldrich and used as received.
N
N
b
7
X
N
SCH(CH3)2
10a,b
15 %
X = O, S
a) 2-(tri-n-butylstannyl)thiophene(furan), CuBr Me2S, Pd(PPh3)4, THF
b) 2-(tri-n-butylstannyl)thiophene(furan), Pd(PPh3)4, THF
Scheme 4. The utilization of the cyano group in the Stille coupling reaction.
Initially, 3-(isopropylsulfanyl)-5-cyano-1,2,4-triazine (7) was
heated with 2-(tri-n-butylstannyl)thiophene or 2-(tri-n-
butylstannyl)furan in the presence of 2.2 equivalent of
CuBr•Me2S as a cofactor and 5 mol % of palladium catalyst.
Under these conditions two kinds of products have been isolated
from the reaction mixture. Compounds 8a (X = S) and 8b (X =
O) were obtained in 50% and 46% yields respectively as a result
of the replacement of alkylsulfanyl group in 7. Disubstituted
products 9a (X = S, 24%) and 9b (X = O, 12%) were formed by
displacement both isopropylsulfanyl and cyano groups. In order
to confirm the course of this reaction, the process was performed
without cofactor CuBr•Me2S (pathway b) which usually is used
in the palladium-catalyzed cross-coupling reactions to polarize
the Pd-S bond in the rate-determining transmetalation step.12 In
this case only cyano group was substituted afforded 3-
isopropylsulfanyl-5-(thiophen-2-yl)-1,2,4-triazine (10a) in 15%
yield. Similarly, coupling of 5-cyano-3-phenyl-1,2,4-triazine 11
and 3-cyano-5,6-diphenyl-1,2,4-triazine 13 with 2-(tri-n-
butylstannyl)thiophene using Pd(PPh3)4 as the palladium source
resulted in the formation of the desired products 12 and 14 in 28
and 25% yield. This means that both compounds were obtained
via Stille coupling involving formation of the corresponding
3-Thiophen-2-yl-1,2,4-triazine 4b6 was obtained according
known procedure.
4.1. General procedure of Stille coupling reaction for 5-
acetyl-3-methylsulfanyl-1,2,4-triazine (1a) with 2-(tri-n-
butylstannyl)thiophene.
A solution of 5-acetyl-3-methylsulfanyl-1,2,4-triazine (1a) (0.25
g, 1.46 mmol) in THF (17 mL), CuBr•Me2S (0.66 g, 3.2 mmol),
corresponding stannyl derivatives (2.9 mmol) and Pd(PPh3)4 (5
mol%) was stirred at reflux under nitrogen until starting
compound was consumed (TLC control). THF was then
evaporated and residue was treated with hexane and filtered. The
filtrate was dissolved in ethyl acetate and washed a few times
with brine. After evaporation of the solvent from the combined
extracts, the remaining residue was purified by column
chromatography using CH2Cl2 as eluent.

4
Tetrahedron
ACCEPTED MANUSCRIPT
4.1.1.
5-Acetyl-3-thiophen-2-yl-1,2,4-triazine (2a): 0.05 g
Hz, J2 = 4.0 Hz, 1H, Th), 7.24 (d, J1 = 4.0 Hz, J2 = 5.2 Hz, 1H,
(12 %), mp 107-108 ºC. Rf (99 % CH2Cl2/acetone) 0.68. IR
Th), 6.86 (d, J1 = 4.0 Hz, J2 = 5.2 Hz 1H, Th), 6.52 (d, J1 = 1.2
Hz, J2 = 4.0 Hz, 1H, Th), 3.33 (q, J = 7.2 Hz, 2H, CH2CH3), 1.27
(t, J = 7.2 Hz, 3H, CH2CH3), 2.32 (s, 3H, Me). 13C NMR (100
MHz, CDCl3) δ: 202.1, 161.2, 157.9, 153.1, 149.8, 148.8, 147.5,
142.5, 139.2, 132.2, 131.1, 129.9, 129.2, 128.9, 128.7, 127.9,
121.4, 31.3, 20.2, 7.9. Anal. Calcd for C20H16N4OS2: C; 61.22, H;
4.08, N; 14.28. Found: C; 60.98, H; 4.41 N; 14.28.
(KBr) cm-1: 1712 (C=O), 1076 (C-S-C). H NMR (400 MHz,
1
CDCl3) δ: 9.52 (s, 1H, triazine), 8.25 (dd, J1 = 1.2 Hz, J2 = 4.0
Hz, 1H, Th), 7.66 (dd, J1 = 1.2 Hz, J2 = 5.2 Hz, 1H, Th), 6.25 (dd,
J1 = 1.2 Hz, J2 = 5.2 Hz, 1H, Th), 2.01 (s, 3H, Me).13C NMR (100
MHz, CDCl3) δ: 199.5, 161.9, 148.4, 142.9, 139.1,132.6, 131.6,
129.2, 25.7. Anal. Calcd for C9H7N3OS: C; 52.68, H; 3.41, N;
20.49. Found: C; 52.65, H; 3.26, N; 20.21.
4.1.7.
5-Propanoyl-3-furan-2-yl-1,2,4-triazine (2d): 0.15 g
4.1.2.
5-[6-Acetyl-2-(thiophen-2-yl)pyridin-3-yl-3-thiophen-2-
(42 %), 107-108 ºC. Rf (99 % CH2Cl2/acetone) 0.40. IR (KBr)
cm-1: 1707 (C=O), 1099 (C-O-C). 1H NMR (400 MHz, CDCl3) δ:
9.53 (s, 1H, triazine), 7.76 (dd, J1 = 0.8 Hz, J2 = 1.6 Hz, 1H, Fu),
7.60 (dd, J1 = 0.8 Hz, J2 = 3.6 Hz, 1H, Fu), 6.68 (dd, J1 = 1.6 Hz,
J2 = 3.6 Hz, 1H, Fu), 3.31 (q, J = 7.2 Hz, 2H, CH2CH3), 1.27 (t, J
= 7.2 Hz, 3H, CH2CH3). 13C NMR (100 MHz, CDCl3) δ : 201.7,
157.7, 149.1, 148.1, 146.8, 142.6, 116.4, 112.8, 31.2, 7.2. Anal.
Calcd for C10H9N3O2: C; 59.11, H; 4.43, N; 20.69. Found: C;
59.05, H; 4.47, N; 20.53.
yl]-1,2,4-triazine-(3a): 0.15 g (40 %), mp 142-143 ºC. Rf (99 %
CH21Cl2/acetone) 0.88. IR (KBr) cm-1: 1700 (C=O), 1062 (C-S-
C). H NMR (400 MHz, CDCl3) δ: 8.95 (s, 1H, triazine), 8.25
(dd, J1 = 0.8 Hz, J2 = 3.6 Hz, 1H, Th), 8.19 (d, J = 8.0 Hz, 1H,
Py), 8.09 (d, J = 8.0 Hz, 1H, Py), 7.65 (dd, J1 = 1.2 Hz, J2 = 5.2
Hz, 1H, Th), 7.50 (dd, J1 = 0.8 Hz, J2 = 5.2 Hz, 1H, Th), 7.24 (dd,
J1 = 4.0 Hz, J2 = 5.2 Hz, 1H, Th), 6.97 (dd, J1 = 3.6 Hz, J2 = 4.8
Hz, 1H, Th), 6.87 (dd, J1 = 1.2 Hz, J2 = 4.0 Hz, 1H, Th), 2.81 (s,
3H, Me). 13C NMR (100 MHz, CDCl3) δ: 199.1, 161.4, 157.2,
153.8, 150.4, 146.6, 141.4, 140.5, 139.1, 132.0, 130.9, 130.8,
129.7, 129.4, 128.7, 128.1, 119.5, 25.7. Anal. Calcd for
C18H12N4OS2: C; 59.30, H; 3.30, N; 15.40. Found: C; 59.30, H;
3.22, N; 15.32.
4.1.8. 5-[4-Methyl-(6-propanoyl-2-furan-2-yl)pyridin-3-yl-3-
furan-2-yl]-1,2,4-triazine (3d): 0.04 g (13 %), oil. Rf (99 %
CH2Cl2/acetone) 0.78. IR (KBr) cm-1: 1701 (C=O). 1H NMR (400
MHz, CDCl3) δ: 8.95 (s, 1H, triazine), 7.88 (s, 1H, Py), 7.74 (dd,
J1 = 0.8 Hz, J2 = 1.6 Hz, 1H, Fu), 7.58 (dd, J1 = 0.4 Hz, J2 = 3.2
Hz, 1H, Fu), 7.16 (dd, J1 = 0.4 Hz, J2 = 1.6 Hz, 1H, Fu), 7.10 (dd,
J1 = 0.8 Hz, J2 = 3.2 Hz, 1H, Fu), 6.66 (dd, J1 = 2.0 Hz, J2 = 3.6
Hz, 1H, Fu), 6.43 (dd, J1 = 2.0 Hz, J2 = 3.6 Hz, 1H, Fu), 3.33 (q,
J = 7.2 Hz, 2H, CH2CH3), 2.28 (s, 3H, Me), 0.92 (t, J = 7.2 Hz,
3H, CH2CH3). 13C NMR (100 MHz, CDCl3) δ: 202.2, 158.1,
157.2, 153.3, 152.4, 149.5, 148.5, 147.6, 146.5, 146.0, 144.2,
128.8, 121.2, 115.8, 112.7, 112.7, 111.9, 31.5, 20.1, 7.9. HRMS
(EI) m/z calcd. for C20H16N4O3, 360.12224 (M+). Found
360.12166.
4.1.3.
5-Acetyl-3-furan-2-yl-1,2,4-triazine (2b): 0.08 g (21 %),
mp. 99-100 ºC. Rf (99 % CH2Cl2/acetone) 0.62. IR (KBr) cm-1:
1702 (C=O), 1070 (C-O-C). 1H NMR (400 MHz, CDCl3) δ: 9.53
(s, 1H, triazine), 7.77 (dd, J1 = 0.8 Hz, J2 = 1.6, 1H, Fu), 7.61 (dd,
J1 = 0.4 Hz, J2 = 3.2, 1H, Fu), 6.68 (dd, J1 = 2.0 Hz, J2 = 3.6, 1H,
Fu), 2.01 (s, 3H, Me). 13C NMR (100 MHz, CDCl3) δ: 199.1,
157.8, 148.1, 146.9, 146.9, 142.4, 116.5, 112.8, 25.3. Anal. Calcd
for C9H7N3O2: C; 57.14, H; 3.70, N; 22.22. Found: C; 57.10, H;
3.80, N; 22.11.
4.1.4.
5-[6-(Acetyl-2-furan-2-yl)pyridin-3-yl-3-furan-2-yl]-
4.1.9.
5-Butanoyl-3-thiophen-2-yl-1,2,4-triazine (2e): 0.06 g
1,2,4-triazine (3b): 0.087 g (26 %), mp. 153-155 ºC. Rf (99 %
CH2Cl2/acetone) 0.20, IR (KBr) cm-1: 1710 (C=O). 1H NMR (400
MHz, CDCl3) δ: 9.53 (s, 1H, triazine), 8.17 (d, J = 8.0 Hz, 1H,
Py), 8.07 (d, J = 8.0 Hz, 1H, Py), 7.75 (d, J = 0.8 Hz, 1H, Fu),
7.58 (d, J = 3.2 Hz, 1H, Fu), 7.31 (d, J = 0.8 Hz, 1H, Fu), 7.24 (d,
J = 3.6 Hz, 1H, Fu), 6.66 (dd, J1 = 1.6 Hz, J2 = 3.2 Hz, 1H, Fu),
6.55 (dd, J1 = 1.6 Hz, J2 = 3.2 Hz, 1H, Fu), 2.81 (s, 3H, Me).13C
NMR (100 MHz, CDCl3) δ: 199.1, 156.4, 154.1, 152.0, 146.5,
146.3, 145.1, 144.5, 142.4, 140.4, 132.0, 128.4, 119.5, 116.5,
(16 %), mp. 89-90 ºC. Rf (99 % CH2Cl2/acetone) 0.62, IR (KBr)
cm-1: 1705 (C=O), 1070 (C-S-C). 1H NMR (400 MHz, CDCl3) δ:
9.53 (s, 1H, triazine), 8.24 (dd, J1 = 1.2 Hz, J2 = 3.6 Hz, 1H, Th),
7.65 (dd, J1 = 1.2 Hz, J2 = 4.8 Hz, 1H, Th), 7.24 (dd, J1 = 1.6 Hz,
J2 = 5.2 Hz, 1H, Th), 3.24 (t, J = 7.2 Hz, 2H, CH2CH2CH3), 1.82
(sek, J = 7.2 Hz, 2H, CH2CH2CH3), 1.05 (t, J = 7.2 Hz, 3H,
CH2CH2CH3). 13C NMR (100 MHz, CDCl3) δ: 201.3, 149.1,
148.1, 142.6, 138.8, 132.3, 131.2, 128.9, 39.5, 16.9, 13.7. Anal.
Calcd for C11H11N3OS: C; 56.65, H; 4.72, N; 18.02. Found: C;
56.67, H; 4.80, N;17.87.
113.0, 112.8, 112.4, 25.7. HRMS (ESI) m/z
calcd for
C18H14N4O3 (M+H)+: 334.10157. Found 334.10143.
4.1.10. 5-[4-Ethyl-6-butanoyl-2-thiophen-2-yl)pyridin-3-yl-3-
thiophen-2-yl]-1,2,4-triazine (3e): 0.015 g (4 %), 154-155 ºC, Rf
(99 % CH2Cl2/acetone) 0.88, IR (KBr) cm-1: 1697 (C=O), 1055
4.1.5.
5-Propanoyl-3-thiophen-2-yl-1,2,4-triazine (2c): 0.10 g
(17 %), mp 112-113 ºC. Rf (99 % CH2Cl2/acetone) 0.65, IR
(KBr) cm-1: 1708 (C=O), 1062 (C-S-C). H NMR (400 MHz,
(C-S-C). H NMR (400 MHz, CDCl3) δ: 8.84 (s, 1H, triazine),
1
1
CDCl3) δ: 9.51 (s, 1H, triazine), 8.23 (d, J1 = 1.2 Hz, J2 = 3.6 Hz,
1H, Th), 7.65 (d, J1 = 1.2 Hz, J2 = 4.8 Hz, 1H, Th), 7.24 (dd, J1 =
4.0 Hz, J2 = 5.6 Hz, 1H, Th), 3.30 (q, J = 7.2 Hz, 2H, CH2CH3),
1.28 (t, J = 7.2Hz, 3H, CH2CH3). 13C NMR (100 MHz, CDCl3) δ:
201.7, 161.9, 147.9, 142.6, 138.8, 132.2, 131.1, 128.8, 31.2, 7.3.
Anal. Calcd for C10H9N3O2: C; 59.11, H; 4.43, N; 20.69. Found:
C; 59.05, H; 4.47, N; 20.53.
7.96 (s, 1H, Py), 8.24 (dd, J1 = 1.2 Hz, J2 = 3.6 Hz, 1H, Th), 7.65
(dd, J1 = 1.2 Hz, J2 = 4.8 Hz, 1H, Th), 7.38 (dd, J1 = 1.2 Hz, J2 =
5.2 Hz, 1H, Th), 7.25 (dd, J1 = 1.2 Hz, J2 = 5.2 Hz, 1H, Th), 6.86
(dd, J1 = 4.0 Hz, J2 = 5.2 Hz, 1H, Th), 6.49 (dd, J1 = 1.2 Hz, J2 =
4.0 Hz, 1H, Th), 3.26 (t, J = 2.8 Hz, 2H, CH2CH2CH3), 2.57 (q, J
= 7.6 Hz, 2H, CH2CH3), 1.84 (qui, J = 7.6 Hz, 2H, CH2CH2CH3),
1.23 (t, J = 7.6 Hz, 3H, CH2CH2CH3), 1.06 (t, J = 7.2 Hz, 3H,
CH2CH3).13C NMR (100 MHz, CDCl3) δ: 201.7, 161.1, 157.8,
154.5, 153.5, 149.9, 147.7, 142.7, 139.3, 132.1, 131.1, 129.5,
129.2, 128.9, 128.8, 127.9, 119.7, 39.8, 26.5, 17.7, 14.6, 13.9.
Anal. Calcd for C22H20N4OS2: C; 62.86, H; 4.76, N; 13.33.
Found: C; 62.72, H; 4.52, N;13.30.
4.1.6.
5-[4-(Methyl-6-propanoyl-2-thiophen-2-yl)pyridin-3-yl-
3-thiophen-2-yl]-1,2,4-triazine (3c): 0.16 g (27 %), 144-145 ºC.
Rf (99 % CH2Cl2/acetone) 0.80. IR (KBr) cm-1: 1697 (C=O),
1058 (C-S-C). 1H NMR (400 MHz, CDCl3) δ: 8.84 (s, 1H,
triazine), 7.91 (s, 1H, Py), 8.22 (d, J1 = 1.2 Hz, J2 = 3.6 Hz, 1H,
Th) 7.64 (d, J1 = 1.2 Hz, J2 = 4.8 Hz, 1H, Th), 7.37 (d, J1 = 1.2

5
4.1.11. 5-Butanoyl-3-furan-2-yl-1,2,4-triazine (2f): 0.036 g (11
%). Rf (99 % CH2Cl2/acetone) 0.42. IR (KBr) cm-1: 1697 (C=O),
1074 (C-O-C). 1H NMR (400 MHz, CDCl3) δ 9.50 (s, 1H,
triazine), 7.79 (dd, J1 = 0.8 Hz, J2 = 1.6 Hz, 1H, Fu), 7.61 (d, J1 =
0.8 Hz, J2 = 3.6 Hz, 1H, Fu), 6.68 (d, J1 = 1.6 Hz, J2 = 3.6 Hz,
1H, Fu), 3.24 (t, J = 7.2 Hz, 2H, CH2CH2CH3), 1.81 (qui, J = 7.2
4.1.17. 5-Cyano-3-furan-2-yl-1,2,4-triazine (8b): 0.19 g (46
ACCEPTED MANUSCRIPT
%), mp 152-153 ºC. Rf (99 % CH2Cl2/acetone) 0.78. IR (KBr)
cm-1: 2142 (C≡N), 1587 (C=C), 1055 (C-O-C). H NMR (400
1
MHz, CDCl3) δ: 9.28 (s, 1H, triazine), 7.79 (dd, J1 = 0.8 Hz, J2 =
1.6 Hz, 1H, Fu), 7.66 (dd, J1 = 0.8 Hz, J2 = 3.6 Hz, 1H, Fu), 6.70
(dd, J1 = 1.6 Hz, J2 = 3.6 Hz, 1H, Fu). 13C NMR (100 MHz,
CDCl3) δ:157.5, 148.0, 147.9, 146.4, 135.0, 118.4, 113.5, 113.3.
Anal. Calcd for C10H4N4O: C; 55.80, H; 2.32, N; 32.56. Found:
C; 55.70, H; 2.34, N; 32.60.
Hz, 2H, CH2CH2CH3), 1.04 (t, J = 7.2 Hz, 3H, CH2CH2CH3). 13
C
NMR (100 MHz, CDCl3) δ: 201.1, 149.1, 148.0, 146.8, 142.5,
116.3, 112.7, 112.7, 39.4, 16.8, 13.6. HRMS (ESI) m/z calcd for
C11H13N3O2 (M+H)+: 219.09576. Found 219.09564.
4.1.18. 3,5-Bi-thiophen-2-yl-1,2,4-triazine (9a): 0.15 g (24 %),
mp 122-123 ºC. Rf (99 % CH2Cl2/acetone) 0.23. IR (KBr) cm-1:
1577 (C=C), 1010 (C-S-C). H NMR (400 MHz, CDCl3) δ: 9.28
4.1.12. 5-[4-Ethyl-(6-butanoyl-2-furan-2-yl)pyridin-3-yl-3-
furan-2-yl]-1,2,4-triazine (3f): 0.006 g (2 %), oil, Rf (99 %
CH2Cl2/acetone) 0.64. IR (KBr) cm-1: 1699 (C=C). 1H NMR (400
MHz, CDCl3) δ: 8.96 (s, 1H, triazine), 7.93 (s, 1H, Py), 7.73 (dd,
J1 = 0.8 Hz, J2 = 1.2 Hz, 1H, Fu), 7.55 (dd, J1 = 0.8 Hz, J2 = 2.8
Hz, 1H, Fu), 7.14 (dd, J1 = 0.8 Hz, J2 = 1.2 Hz, 1H, Fu), 7.09 (dd,
J1 = 0.8 Hz, J2 = 2.8 Hz, 1H, Fu) 6.65 (dd, J1 = 1.6 Hz, J2 = 2.0
Hz, 1H, Fu), 6.42 (dd, J1 = 1.6 Hz, J2 = 2.0 Hz, 1H, Fu), 3.26 (t, J
= 7.2 Hz, 2H, CH2CH2CH3), 1.83 (q, J = 7.2 Hz, 2H, CH2CH3),
1.62 (qui, J = 7.6 Hz, 2H, CH2CH2CH3), 1.21 (t, J =7.6 Hz, 3H,
CH2CH2CH3), 1.17 (t, J = 7.2 Hz, 3H, CH2CH3). HR-EI m/z:
Calcd for C22H20N4O3: 388.15352. Found 388.15294.
1
(s, 1H, triazine), 7.66 (dd, J1 = 0.8 Hz, J2 = 1.6 Hz, 1H, Th), 7.65
(dd, J1 = 0.8 Hz, J2 = 1.6 Hz, 1H, Th), 7.48 (dd, J1 = 0.8 Hz, J2 =
3.6 Hz, 1H, Th), 7.45 (dd, J1 = 0.8 Hz, J2 = 3.6 Hz, 1H, Th), 6.59
(dd, J1 = 1.6 Hz, J2 = 3.6 Hz, 1H, Th), 6.56 (dd, J1 = 1.6 Hz, J2 =
3.6 Hz, 1H, Th). 13C NMR (100 MHz, CDCl3) δ: 150.0, 149.3,
147.4, 147.2, 146.6, 146.5, 142.3, 116.8, 115.7, 113.6, 112.8. ESI
(M+H)+ calcd. for C11H8N3S2: 246.01542. Found: 246.01543.
4.1.19. 3,5-Bi-furan-2-yl-1,2,4-triazine (9b): 0.04 g (12 %), mp
164ºC. Rf (99 % CH2Cl2/acetone) 0.20. IR (KBr) cm-1: 1595
1
(C=C), 1015 (C-S-C). H NMR (400 MHz, CDCl3) δ: 9.35 (s,
1H, triazine), 7.73 (dd, J1 = 0.8 Hz, J2 = 1.6 Hz, 1H, Fu), 7.71
(dd, J1 = 0.8 Hz, J2 = 1.6 Hz, 1H, Fu), 7.55 (dd, J1 = 0.8 Hz, J2 =
3.6 Hz, 1H, Fu), 7.53 (dd, J1 = 0.8 Hz, J2 = 3.6 Hz, 1H, Fu), 6.67
(dd, J1 = 2.0 Hz, J2 = 3.6 Hz, 1H, Fu), 6.62 (dd, J1 = 2.0 Hz, J2 =
3.6 Hz, 1H, Fu). 13C NMR (100 MHz, CDCl3) δ:157.1, 149.7,
148.9, 147.1, 146.8, 146.1, 141.9, 116.5, 115.3, 113.2, 112.4.
HRMS (ESI) m/z calcd for C11H9N3O2 (M+H)+: 215.06446.
Found 215.06444.
4.1.13. 5-[(6-Acetyl-2-phenyl-2-yl)pyridin-3-yl-3-phenyl-2-yl]-
1,2,4-triazine (3g): 0.007 g (24 %). Rf (99 % CH2Cl2/acetone)
0.74. IR (KBr) cm-1: 1712 (C=O). 1H NMR (400 MHz, CDCl3) δ:
8.70 (s, 1H, triazine), 8.60 (dd, J1 = 6.4 Hz, J2 = 12.8 Hz, 2H, Ph),
8.44 (d, J = 7.6 Hz, 1H, Py), 8.21 (d, J = 8.0 Hz, 1H, Py), 7.60-
7.55 (m, 3H, Ph), 7.49-7.40 (m, 5H, Ph), 2.86 (s, 3H, Me). 13C
NMR (100 MHz, CDCl3) δ: 199.6, 163.9, 157.4, 154.2, 147.4,
143.1, 140.4, 138.2, 134.5, 132.4, 132.1, 129.9, 129.8, 129.1,
129.0, 128.9, 128.5, 128.4, 120.1, 29.7, 25.9, 25.4. HRMS (EI)
m/z calcd. for C22H17N4O (M+H)+: 353.13935. Found:
353.13969.
4.2. General procedure for bromination of 5a and 5b.
To a round bottom flask 1.0 mmol of 4a or 4b respectively in 5
ml DMF was added and 1.1 mmol NBS was added in few
portions. The reaction was stirred at room temperature to
disappear starting compound. The mixture was poured into ice-
water. The precipitate was filtered and dried. The crude product
was purified on chromatography column on silica gel using
dichloromethane as eluent. Compound was obtained as light
yellow solid.
4.1.14. 5-[(6-Acetyl-2-metylsulfanyl)pyridin-3-yl-3-
metylsulfanyl-2-yl]-1,2,4-triazine (3h): 0.003 g (6.4 %), mp. 136-
137 ºC. Rf (99 % CH2Cl2/acetone) 0.28, IR (KBr) cm-1: 1693
(C=O). 1H NMR (400 MHz, CDCl3) δ: 9.41 (s, 1H, triazine), 8.06
(d, J = 8.0 Hz, 1H, Py), 7.87( d, J = 7.6 Hz, 1H, Py), 2.77 (s, 3H,
Me), 2.75 (s, 3H, SMe), 2.67 (s, 3H, SMe). MR (100 MHz,
CDCl3) δ: 199.0, 173.9, 159.6, 154.0, 153.6, 143.7, 138.4, 130.9,
116.6, 25.9, 14.2, 13.9. HRMS (MSI) m/z for C12H13N4OS2
(M+H)+: 293.05183. Found 293.05253.
4.2.1.
3-[(5-Bromo-furan-2-yl)-5-(1-methoxyiminoethyl)]-
1,2,4-triazine (5a): 0.03 g (45 %), mp 160-161 ºC. Rf (99 %
CH2Cl2/acetone) 0.74, IR (KBr) cm-1: 1591 (C=C), 1049 (C-O-
C), 1020 (N-O-CH3), 694 (C-Br). 1H NMR (400 MHz, CDCl3) δ:
9.58 (s, 1H, triazine), 7.44 (d, J = 3.6 Hz, 1H, Fu), 7.57 (d, J =
3.6 Hz, 1H, Fu), 3.99 (s, 3H, OMe), 2.31 (s, 3H , Me). Anal.
Calcd for C10H9BrN4O2: C; 40.40, H; 3.00, N; 18.80. Found: C;
40.62, H; 2.91, N; 18.70.
4.1.15. 3-Furan-2-yl-5-(1-methoxyiminoethyl)-1,2,4-triazine (4a):
0.12 g (61 %), mp 132-133 ºC. Rf (99 % CH2Cl2/acetone) 0.21,
1
IR (KBr) cm-1: 1585 (C=C), 1035 (C-O-C), 1016 (N-O-CH3). H
NMR (400 MHz, CDCl3) δ: 9.56 (s, 1H, triazine), 7.71 (dd, J1 =
1.0 Hz, J2 = 1.8 Hz, 1H, Fu ), 7.49 (dd, J1 = 1.0 Hz, J2 = 3.5 Hz,
1H, Fu), 6.62 (dd, J1 = 1.8 Hz, J2 = 3.5 Hz, 1H, Fu), 4.14 (s, 3H ,
OMe), 2.32 (s, 3H, Me). HR (ESI) m/z calcd. for C10H11N4O2
(M+H)+: 219.08765. Found: 219.08748.
4.2.2.
3-(5-Bromo-thiophen-2-yl)-1,2,4-triazine (5b) 0.68 g
(48 %), mp 162.5 ºC. Rf (99 % CH2Cl2/acetone) 0.46. IR (KBr)
1
cm-1: 1535 (C=C), 1047 (C-S-C), 659 (C-Br). H NMR (400
4.1.16. 5-Cyano-3-thiophen-2-yl-1,2,4-triazine (8a): 0.19 g (50
MHz, CDCl3) δ: 9.05 (d, J = 2.0 Hz, 1H, triazine), 8.52 (d, J =
2.0 Hz, 1H, Th), 7.90 (d, J = 4.0 Hz, 1H, Th), 7.16 (d, J = 4.0 Hz,
1H, Th). 13C NMR (100 MHz, CDCl3) δ: 148.8, 147.2, 131.6,
130.7, 119.5. HRMS (ESI) m/z calcd. for C7H6BrN3S (M+H)+:
244.93952. Found 244.93949.
%), mp 155 ºC. Rf (99 % CH2Cl2/acetone) 0.81. IR (KBr) cm-1:
1
2135 (C≡N), 1606 (C=C), 1120 (C-S-C). H NMR (400 MHz,
CDCl3) δ: 8.75 (s, 1H, triazine), 7.68 (dd, J1 = 0.8 Hz, J2 = 1.6
Hz, 1H, Th), 7.41 (dd, J1 = 0.8 Hz, J2 = 3.6 Hz, 1H, Th), 6.60
(dd, J1 = 1.6 Hz, J2 = 3.6 Hz, 1H, Th), 13C NMR (100 MHz,
CDCl3) δ: 157.5, 148.0, 147.9, 146.4, 135.0, 118.4, 113.5, 113.3.
HRMS (ESI) m/z calcd. for C8H5N4S (M+H)+: 189.02294.
Found: 189.02272.

6
Tetrahedron
4.3. Compounds 6a and 6b were obtained according from 5a
1H, Fu). 13C NMR (100 MHz, CDCl3) δ:155.8, 155.3, 155.0,
ACCEPTED MANUSCRIPT
and 5b following the general Stille coupling procedure without
using of CuBr•Me2S.
149.8, 146.1, 135.5, 135.41, 130.6, 129.7, 129.5, 129.4, 128.5,
115.1, 112.4. HRMS (ESI) m/z calcd. for C19H15N3O (M+H)+:
301.11649. Found 301.11646.
4.3.1.
3-[(5-(Furan-2-yl)-furan-2-yl)-5-(1-
References and notes
methoxyiminoethyl)]-1,2,4-triazine (6a): 0.02 g (26 %), mp 139-
140 ºC. Rf (99 % CH2Cl2/acetone) 0.30. IR (KBr) cm-1: 1575
1
1. Lindsay W., Layton M. E. “Science of Synthesis, Houben-Weyl
Methods of Molecular Transformations” in Georg Thieme Verlag,
Stuttgart, Ed.: Weinreb S. M., 2004, Vol. 17, p. 357. Raw S.,
Taylor R. J. K. in “Advances in Heterocyclic Chemistry”, Ed.:
Katritzky, A. R 2010, Vol. 100, 75–100. Neunhoeffer H. in
“Comprehensive Heterocyclic Chemistry” Eds. Katritzky A. R.,
Rees C. W., Scriven E. F., 1996, Vol. 6, Pergamon Press, Oxford.
V. Charushin, V. Rusinov, O. Chupakhin, in “Comprehensive
Heterocyclic Chemistry III” Ed. Katritzky A. R. 2008, Vol 9, 144-
152. Boger, D. L. Chem. Rev. 1986, 86, 781. Boger, D. L.;
Weinreb, S. N. In: “Hetero Diels-Alder Methodology in Organic
Synthesis”, Ed. Wasserman, H. H., Academic: New York, 1987; p
323. Taylor, E. C.; Macor, J. E.; French, L. J. Org. Chem. 1991,
56, 1807. Marcelis, A. T. M.; van der Plas, H. C. Trends in
Heterocyclic Chemistry 1991, 111.
(C=C), 1051 (N-O-CH3), 1016, (C-O-C). H NMR (400 MHz,
CDCl3) δ: 9.55 (s, 1H, triazine), 7.55 (d, J = 3.2 Hz, 1H, Fu),
7.49 (d, J = 0.8 Hz, 1H, Fu), 6.88 (d, J = 3.2 Hz, 1H, Fu), 6.77 (d,
J = 3.6 Hz, 1H, Fu), 6.52 (dd, J1 = 1.6 Hz, J2 = 3.2 Hz, 1H, Fu),
4.14 (s, 3H, OMe), 2.33 (s, 3H, Me). 13C NMR (100 MHz,
CDCl3) δ: 157.2, 153.3, 153.1, 150.2, 148.9, 146.0, 143.5, 117.8,
113.7, 112.2, 108.1, 107.9, 63.8, 9.9. HRMS (ESI) m/z calcd. for
C14H13N4O3 (M+H)+: 285.09793. Found: 285.09822.
4.3.2.
3-(2,2’-Bi-thiophen-5-yl)-1,2,4-triazine (6b): 0.119 g
(94 %), mp 141-143 ºC. Rf (99 % CH2Cl2/acetone) 0.42. IR
1
(KBr) cm-1: 1516 (C=C), 1047 (C-S-C). H NMR (400 MHz,
CDCl3) δ: 9.03 (d, J = 2.0 Hz, 1H, triazine), 8.55 (d, J = 2.0 Hz,
1H, Th), 8.07 (d, J = 4.0 Hz, 1H, Th), 7.33 (d, J = 3.6 Hz, 1H,
Th), 7.31 (d, J = 4.8 Hz, 1H, Th), 7.27 (d, J = 5.2 Hz, 1H, Th).
7.07 (t, J = 4.4 Hz, 1H, Th). 13C NMR (100 MHz, CDCl3)
δ:161.49, 148.59, 146.70, 143.46, 137.32, 136.70, 131.44,
128.11, 125.79, 124.99, 124.85. Anal. Calcd for C11H7N3S2: C;
53.87, H; 2.86, N; 17.14. Found: C; 53.71, H; 2.84, N; 16.90.
2. Rykowski A., Lipinska T., Synth. Comm.,1996, 26, 4409.
Branowska D., Ostrowski S., Rykowski A. Chem. Pharm. Bull.,
2002, 4, 463. Mojzych M., Rykowski A., Heterocycles, 2007, 71,
2449.
3. Rykowski A., Branowska D., Mąkosza M. and Phan van Ly, J.
Heterocyclic Chem., 1996, 33, 1567.
4. Rykowski A., Olender E., Branowska D., van der Plas H.C. Org.
Prep. Proc. Int., 2001, 33, 501.
5. Branowska D., Siuchta O., Karczmarzyk Z., Wysocki W.,
Wolińska E., Mojzych M., Kawęcki R., Tetrahedron Lett., 2011,
52, 7054.
6. Alphonse F.-A., Suzenet F., Keromones A., Lebret B.,
Guillaument G., Org. Lett. 2003, 5, 803.
7. Veith M., Belot C., Huch V., Lui H. L., Guyard L., Knorr M.,
Wickleder C., Eur. J. Inorg. Chem., 2010, 879. Branowska D.,
Chaciak B., Siuchta O., Olender E., Ledwon P., Lapkowski M.,
Poronik E., Wysocki W., Karczmarzyk Z., Skora L., Filapek M.,
Krompiec S., Urbanczyk-Lipkowska Z., Kalicki P., New J. Chem.
2013, 37, 1982-1988.
4.3.3.
3-Isopropyl-5-thiophen-2-yl-1,2,4-triazine (10a): (15
%). Rf (99 % CH2Cl2/acetone) 0.64, IR (KBr) cm-1: 1587 (C=C),
1015 (C-S-C). 1H NMR (400 MHz, CDCl3) δ: 9.08 (s, 1H,
triazine), 7.75 (d, = 3.6 Hz, 1H, Th), 7.61 (d, J = 0.8 Hz, 1H, Th),
6.68 (d, J = 1.6, 1H, Th), 4.06 (sep, J = 6.8 Hz, 1H, CH(CH3)2),
1.49 (d, J = 6.8 Hz, 6H, CH(CH3)2). 13C NMR (100 MHz, CDCl3)
δ: 164.0, 146.2, 142.7, 116.8, 36.8, 23.0. HRMS (ESI) m/z calcd.
for C10H12N3S2 (M+H)+: 238.04672. Found 238.04647.
8.
Lipińska T., Branowska D., Rykowski A., Chem. of Heterocyclic
Comp., 1999, 3, 381.
4.3.4.
3-Phenyl-5-furan-2-yl-1,2,4-triazine (12): 0.06 g (28
9. Y. Chiang, A. J. Kresge, E. T. Krogh, J. Am. Chem. Soc. 1988,
110, 2601.
10. Ohba S., Konno S., Yamanaka H., Chem. & Pharm. Bull., 1991,
39, 486.
11. Tobisu M., Kinuta H., Kita Y., Remond E., Chatani N., J. Am.
Chem. Soc. 2012, 134, 115 Kinuta H., Kita Y., Remmond E.,
Tobisu M., Chatani N., Synthsis, 2012, 44, 2999. Kita Y. Tobisu
M., Chatani N., Org. Lett. 2010, 12, 1864. Tobisu M., Kita Y.,
Ano Y., Chatani N., J. Am.Chem. Soc., 2008, 130, 15982. G.W.
Parshall J. Am. Chem. Soc. 1974, 96, 2361.
%), mp 110 ºC. Rf (99 % CH2Cl2/acetone) 0.68. IR (KBr) cm-1:
1592 (C=C). 1H NMR (400 MHz, CDCl3) δ: 9.45 (s, 1H,
triazine), 8.60 - 8.57 (m, 2H, Ph), 7.75 (dd, J1=0.4 Hz, J2=1.6 Hz,
1H, Fu), 7.60 (dd, J1 = 0.4 Hz, J2= 3.6 Hz, 1H, Fu), 7.57-7.53 (m,
3H, Ph), 6.69 (dd, J1 =2.0 Hz, J2 = 3.6 Hz, 1H, Fu). 13C NMR
(100 MHz, CDCl3) δ: 163.6, 149.8, 147.3, 147.2, 142.8, 135.3,
132.0, 129.1, 128.7, 116.4, 113.6. HRMS (ESI) m/z calcd. for
C13H10N3O (M+H)+: 224.02890. Found: 224.02897.
12. Libeskind L.S., Srogol J., J. Am. Chem. Soc., 2000, 122, 11260.
Savarin C., Srogol J., Libeskind L. S., Org. Lett., 2001, 3, 91.
Savarin C., Libeskind L. S. Org. Lett., 2001, 3, 2149. Kusturin C.
L. Liebeskind L. S., Neumann W., Org. Lett. 2002, 4, 983.
4.3.5.
5,6-Di-phenyl-3-furan-2-yl-1,2,4-triazine (14): 0.06 g
(25 %), mp 187 ºC. Rf (99 % CH2Cl2/acetone) 0.65. IR (KBr) cm-
1: 1585 (C=C), 1027 (C-O-C). H NMR (400 MHz, CDCl3) δ:
1
7.74 (br s, 1H, triazine), 7.62- 7.57 (m, 5H, Ph), 7.45-7.35 (m,
6H, Ph), 6.65 (br s, 1H, Fu), 6.69 (dd, J1 = 2.0 Hz, J2 = 3.6 Hz,