Synthesis and structure of 4-hydroxy-4-fluoroalkyl-1,4-dihydroimidazo[5,1- c][1,2,4]triazines

Article abstract of DOI:10.1134/S1070428009040174

Azo coupling of fluorinated 1,3-diketones with 4-ethoxycarbonyl-1H- imidazole-5-diazonium chloride led to the formation of 4-hydroxy-4- polyfluoroalkyl-1,4-dihydroimidazo[5,1-c][1,2,4]triazines. According to the ¹H and ¹⁹F NMR data,

Full text of DOI:10.1134/S1070428009040174

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2009, Vol. 45, No. 4, pp. 572–580. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © E.V. Shchegol’kov, E.V. Sadchikova, Ya.V. Burgart, V.I. Saloutin, 2009, published in Zhurnal Organicheskoi Khimii, 2009, Vol. 45,
No. 4, pp. 586–594.
Synthesis and Structure of 4-Hydroxy-4-fluoroalkyl-1,4-
dihydroimidazo[5,1-c][1,2,4]triazines
E. V. Shchegol’kova, E. V. Sadchikovab, Ya. V. Burgarta, and V. I. Saloutina
a Postovskii Institute of Organic Synthesis, Ural Division, Russian Academy of Sciences,
ul. S. Kovalevskoi 22, Yekaterinburg, 620041 Russia
e-mail: saloutin@ios.uran.ru
b Ural State Technical University, Yekaterinburg, Russia
Received July 17, 2008
Abstract—Azo coupling of fluorinated 1,3-diketones with 4-ethoxycarbonyl-1H-imidazole-5-diazonium chlo-
ride led to the formation of 4-hydroxy-4-polyfluoroalkyl-1,4-dihydroimidazo[5,1-c][1,2,4]triazines. According
1
to the H and 19F NMR data, these compounds in solution give rise to ring–chain tautomerism via opening of
the C4–N5 bond, which is especially characteristic of dihydroimidazotriazines with a polyfluoroalkyl substituent
longer than trifluoromethyl group.
DOI: 10.1134/S1070428009040174
1,3-Diketones, including fluorinated derivatives,
are known to react with arenediazonium salts to give
the corresponding 1,2,3-triketone 2-arylhydrazones
which are widely used as intermediate products in the
synthesis of biologically active compounds, dyes,
ligands for complex formation with metals, etc. [1].
Reactions of hetarenediazonium salts with nonfluor-
inated 1,3-diketones do not always lead to the forma-
tion of open-chain hydrazones; in some cases, the
products are azolotriazines resulting from spontaneous
intramolecular cyclization with participation of one
carbonyl group [2].
We previously showed that the direction of azo
coupling of fluorinated 1,3-diketones with hetarenedi-
azonium salts is determined mainly by the hetarene
structure. For example, azo coupling of fluorinated
1,3-diketones with 1,2,4-triazole-3-diazonium and
4-ethoxycarbonylpyrazole-3-diazonium chlorides gives
the corresponding stable 4-fluoroalkyl-4-hydroxy-1,4-
dihydroazolo[5,1-c]triazines instead of the expected
1,2,3-triketone 2-hetarylhydrazones [3]. In continua-
tion of these studies, in the present work we examined
azo coupling of fluorine-containing 1,3-diketones Ia–
Ih with 4-ethoxycarbonyl-1H-imidazole-5-diazonium
chloride. It is known that nonfluorinated 1,3-diketones
react with imidazole-5-diazonium salts to afford
1,2,3-triketone 2-imidazolylhydrazones which undergo
intramolecular condensation to imidazo[5,1-c][1,2,4]-
triazines on heating in boiling acetic acid [4]. Imidazo-
triazines are isosteric to purine bases; therefore, they
could be capable of inducing metabolic disorders and
inhibiting protein biosynthesis [5]. Some imidazotri-
azines were reported to inhibit protein kinase [6] and
phosphodiesterase [7].
We found that fluorinated 1,3-diketones Ia–Ih react
with 4-ethoxycarbonyl-1H-imidazole-5-diazonium
Scheme 1.
H
N
·
·
·
O
O
RF
N
R
COOEt
O
N
RF
R
HN
Me2CO, AcONa
R
N
+
N
EtO
O
O
O
N2 Cl–
·
·
·
NH
RF
O
N
H
H
N
N
H
OEt
·
·
·
O
Ia–Ih
A
B, IIa–IIh
RF = CF3, R = Me (a), t-Bu (b), Ph (c), 2-furyl (d), 1-naphthyl (e); RF = H(CF2)2, R = Ph (f); RF = C3F7, R = Me (g), Ph (h).
572

SYNTHESIS AND STRUCTURE OF 4-HYDROXY-4-FLUOROALKYL-...
573
chloride in acetone in the presence of sodium acetate at
reduced temperature to produce imidazo[5,1-c][1,2,4]-
triazines IIa–IIh (Scheme 1). However, to distinguish
between isomeric 1,2,3-triketone 2-imidazolylhydra-
zones A and 4-hydroxy-4-fluoroalkyl-1,4-dihydroimid-
azo[5,1-c][1,2,4]triazines B, the structure of the isolat-
ed products was thoroughly studied by IR and NMR
spectroscopy and X-ray analysis.
The structure of compounds IIa–IIh in solution
was studied by NMR spectroscopy. The H and
1
19F NMR spectra of trifluoromethyl derivatives IIa–IIe
in CDCl3, acetone-d6, and DMSO-d6 contained only
one set of signals, indicating the presence of only one
among possible isomers in solution. However, the
1H and 19F NMR patterns of polyfluoroalkyl-substi-
tuted compounds IIf–IIh in some cases implied the
presence of more than one isomer.
According to the X-ray diffraction data, compound
IIh has the structure of ethyl 3-benzoyl-4-heptafluoro-
propyl-4-hydroxy-1,4-dihydroimidazo[5,1-c][1,2,4]tri-
azine-8-carboxylate (see figure). The O1 and H2 atoms
are linked through intramolecular hydrogen bond with
the following parameters: O1···H2 1.77(5) Å, ∠O1H2O2
156(2)°, ∠C4O2H2 100(1)°. The fused heterocyclic
fragment is almost planar; the C4 and N1 atoms deviate
from the N2C3N5C6N7C8C8a plane by 0.33(2) and
0.13(2) Å, respectively. The heptafluoropropyl group is
oriented almost orthogonally to the triazine ring plane
(85.4°), while the hydroxy group declines by an angle
of 39.6°. One more intramolecular hydrogen bond is
formed between the O3 and H1 atoms: O3 ···H1
2.40(7) Å, ∠N1H1O3 113(1)°, ∠C19O3H1 105(2)°. Judg-
ing by the O···H distances, the O3···H1 hydrogen bond
is weaker than O1···H2.
13
In the C NMR spectrum of IIa in DMSO-d6, the
quartet signal from the trifluoromethyl carbon atom
was located at δC ~79 ppm, which is typical of sp3-hy-
bridized carbon atom in heterocyclic structure B [3].
1
The H NMR spectra did not allow us to reliably dis-
tinguish between cyclic and open-chain structures of
compounds IIa–IIh because of similarity of supposed
spectral parameters of imidazotriazines B and imid-
azolylhydrazones A.
The 19F NMR data are more appropriate for this
purpose. The chemical shifts of fluorine in CF3 and
α-CF2 groups in open-chain 1,2,3-triketone 2-(het)aryl-
hydrazones and cyclic azolotriazines differ consider-
ably, depending on the nature of the neighboring
carbon atoms. Fluorine atoms in CF3 groups attached
to sp3-hybridized carbon atom in dihydroazolotriazines
resonate in a stronger field (δF ~79 ppm in CDCl3 and
85 ppm in DMSO-d6) than do the corresponding fluor-
ine nuclei in open-chain hydrazones (δF ~91 ppm in
CDCl3 and 93 ppm in DMSO-d6), where the CF3 group
is attached to sp2-hybridized carbon atom [9, 11]. The
observed chemical shifts of fluorine atoms in the CF3
groups of compounds IIa–IIe (δF 78.3–78.9 ppm
in CDCl3, 81.4–82.0 ppm in acetone-d6, and 83.0–
83.5 ppm in DMSO-d6) suggest their cyclic structure.
In most cases, the CF3 signals are doublets (JFH = 0.7–
The presence of intramolecular bonds in dihydro-
imidazotriazine IIh also follows from the IR spectrum
where the absorption band corresponding to stretching
vibrations of two carbonyl groups is strongly broad-
ened and displaced to lower frequencies (ν 1670 cm–1)
relative to its position typical of carbonyl groups con-
jugated with double C=C or C=N bond [8].
The IR spectra of crystalline samples of compounds
IIa–IIg were essentially similar to the spectrum of IIh.
All compounds IIa–IIh displayed in the IR spectra
two very strong absorption bands in the regions 3280–
3230 and 3170–3100 cm–1 due to stretching vibrations
of OH and NH groups, as well as one broadened or
two strong absorption bands in the region 1695–
1665 cm–1 due to vibrations of ester and ketone (acyl
or aroyl) carbonyl groups. Analogous pattern was ob-
served previously in the IR spectra of 4-fluoroalkyl-4-
hydroxy-1,4-dihydroazolo[5,1-c][1,2,4]triazines [3]. In
contrast, the IR spectra of 1,2,3-triketone 2-arylhydra-
zones [9] and 2-pyrazolylhydrazones [10] character-
istically contain a very weak broadened absorption
band in the region 3110–3040 cm–1, which belongs to
stretching vibrations of the NH group in the hydrazone
fragment. The above data indicate that all compounds
IIa–IIh in the crystalline state have the structure of
cyclic isomer B.
F7
F6
C18
F5
F4
F2
C17
H3
C6
F1
C16
F3
N7
C8
H2 O2
C9
N5
C4
C3
O1
O4
C21
C19
O3
C8a
N1
H1
C10
C20
C11
C15
C14
N2
C12
C13
Structure of the molecule of ethyl 3-benzoyl-4-heptafluoro-
propyl-4-hydroxy-1,4-dihydroimidazo[5,1-c][1,2,4]triazine-
8-carboxylate (IIh) according to the X-ray diffraction data.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 4 2009

SHCHEGOL’KOV et al.
574
Scheme 2.
N
N
H
N
O
O
·
·
·
NH
HN
O
O
RF
N
EtO
N
OEt
N
R
N
H
O
H
O
N
N
RF
R
N
H
OEt
·
·
·
O
R
RF
A''
O
O
B
A'
1.2 Hz) due to coupling with 3-H in the imidazole ring;
the 3-H proton resonates in the H NMR spectra as
a broadened quartet or singlet.
atom. Then the second set of signals should be as-
signed to open-chain tautomer A. The 1H NMR spectra
of IIf also contained doubled signals from most pro-
tons (see Experimental).
1
Interestingly, the 19F NMR spectrum of compound
IIa in DMSO-d6, recorded repeatedly in 24 h after dis-
solution, contained low-intensity singlets at δF 93.07
(5%) and 89.10 ppm (1%) in addition to the doublet at
δF 83.17 ppm (94%), belonging to cyclic structure B
(see table). While studying steric structure of a large
series of trifluoromethyl-containing 1,2,3-triketone
2-arylhydrazones, we previously showed [11] that
fluorine signals of the CF3CO group involved in intra-
molecular hydrogen bond with the NH proton of the
arylhydrazone fragment appear in the 19F NMR spectra
(acetone-d6) at δF ~89 ppm and that fluorine nuclei in
the free CF3CO group resonate at δF ~93 ppm. Taking
these data into account, the new signals observed in the
19F NMR spectrum of IIa in DMSO-d6 should be as-
signed to geometric isomers of open-chain 1,1,1-tri-
fluoropentane-2,3,4-trione 2-imidazolylhydrazone with
free (A′) and H-bonded carbonyl group (A″) at the tri-
fluoromethyl substituent (Scheme 2).
In the 19F NMR spectrum of a solution of IIf in
acetone-d6 we observed three sets of signals. The
major set (72%) was assigned to cyclic isomer B,
whereas the two minor sets corresponded to open-
chain isomers A. The α-CF2 fluorine nuclei in A″
(25%) and A′ (3%) had different chemical shifts
(δF ~41.9 and ~42.2 ppm, respectively). It may be pre-
sumed that the tetrafluoroethyl group in A″ is contig-
uous to the carbonyl group involved in intramolecular
hydrogen bond with the hydrazone fragment and that
the same group in A′ is linked to free carbonyl group
(Scheme 2). Most proton signals of isomer A′ are
difficult to distinguish because of their low intensity
and superposition of signals from other isomers.
It remained to determine which of the open-chain
19
isomers of compound IIf is observed in the F NMR
spectrum recorded in DMSO-d6. Taking into account
similarity of the chemical shifts of fluorine nuclei in
the α-CF2 group linked to H-bonded carbonyl group
in the 19F NMR spectrum in (CD3)2CO (A″,
δF 41.95 ppm) and those observed in DMSO-d6
(δF 41.98 ppm), structure A″ was presumed.
1
The H and 19F NMR spectra of tetrafluoroethyl
derivative IIf in CDCl3 contained one set of signals
corresponding to cyclic structure B; fluorine atoms in
the tetrafluoroethyl group gave rise to an AB spin
system due to the presence of neighboring asymmetric
carbon atom. However, the 1H and 19F NMR spectra of
the same compound in DMSO-d6 displayed two sets of
signals, the major of which (95%) was assigned to
cyclic isomer B. The minor set (5%) was characterized
by a different pattern. The HCF2 group gave a doublet
1
19
According to the H and F NMR data, compound
IIg having heptafluoropropyl and methyl groups in
CDCl3 exists as single cyclic tautomer B, while in
DMSO-d6 and acetone-d6 mixture of three isomers B,
A′, and A″ at different ratios is present (see Experi-
mental and table). Isomers A′ and A″ can be distin-
3
1
of triplets (2JFH = 52.8, JFF = 7.5 Hz), and the α-CF2
guished in the H NMR spectra on the basis of
signal was a doublet of multiplets (3JFF = 7.5 Hz). This
pattern is typical of tetrafluoroethyl group attached to
a carbonyl carbon atom. In addition, fluorine atoms
in the α-CF2 group resonated in a weaker field
(δF ~42 ppm) as compared to cyclic isomer B
(δF ~37 ppm). The observed downfield shift is typical
of α-CF2 group attached to sp2-hybridized carbon
chemical shifts of protons in the acetyl methyl group.
It is known [11] that signal from acetyl group involved
in intramolecular hydrogen bond with NH group is
displaced downfield. Signals in the 19F NMR spectrum
of IIg were assigned to isomers A′, A″, and B by
analysis of chemical shifts of fluorine nuclei in the
α-CF2 group. The fractions of cyclic structure B in
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 4 2009

SYNTHESIS AND STRUCTURE OF 4-HYDROXY-4-FLUOROALKYL-...
575
Isomeric compositions of compounds IIa–IIh in different
DMSO-d6 and acetone-d6 were almost equal (60 and
62%, respectively), whereas the ratio of open-chain
isomers A′ and A″ strongly depended on the solvent.
Isomer A″ with the H-bonded fluoroacyl fragment pre-
dominated in DMSO-d6, while in going to acetone-d6
the fractions of isomers A′ and A″ leveled (see table).
solvents according to the 19F NMR data
Isomer fraction, %
Comp.
Solvent
no.
A'
A″
B
IIa
CDCl3, acetone-d6,
CD3OD, DMSO-d6
–
–
100
In the H and 19F NMR spectra of IIh in CDCl3,
1
a
DMSO-d6
05
01
09
–
094
091
100
a minor set of signals due to open-chain isomer A″
(3%) was present in addition to signals belonging to
isomer B (97%). The fraction of isomer A″ increased
to 20% in going to DMSO-d6 (B, 80%), and the spectra
of a solution in acetone-d6 contained signals from three
isomers B (82%), A′ (5%), and A″ (13%; see table).
The α-CF2 signals in the 19F NMR spectra of IIh in
CDCl3 (δF 47.02 ppm) and DMSO-d6 (δF 50.48 ppm)
were observed in a weaker field than those found for
isomers A′ (δF 51.50 ppm) and A″ (δF 51.21 ppm) in
acetone-d6. Therefore, these signals were assigned to
isomer A″ in which intramolecular hydrogen bond is
formed between the fluorinated acyl group and hydra-
zone fragment.
Pyridine-d5
IIb
IIс
IId
CDCl3, DMSO-d6,
acetone-d6
–
–
–
CDCl3, DMSO-d6,
acetone-d6
–
–
100
100
CDCl3, DMSO-d6,
acetone-d6, CD3OD
Pyridine-d5
–
–
03
–
097
100
IIe
IIf
CDCl3, DMSO-d6,
acetone-d6
CDCl3
–
–
–
100
095
072
091
079
091
100
062
060
097
080
082
083
085
082
DMSO-d6
Acetone-d6
CD3OD
05
25
07
05
03
–
1
19
03
02
16
06
–
Thus the data of IR and H and F NMR spectros-
copy and X-ray analysis showed that azo coupling of
fluorinated 1,3-diketones Ia–Ih with 4-ethoxycar-
bonyl-1H-imidazole-5-diazonium chloride leads to the
formation of 4-fluoroalkyl-4-hydroxy-1,4-dihydro-
imidazo[5,1-c][1,2,4]triazines IIa–IIh which give rise
to ring–chain isomerism in solution via dissociation of
the C4–N5 bond. We can also state that, unlike analo-
gous transformations of nonfluorinated 1,3-diketones,
compounds Ia–Ih having electron-withdrawing poly-
fluoroalkyl substituents are converted into hydrated
heterocyclic structures. Presumably, open-chain
1,2,3-triketone 2-imidazolylhydrazones A are unstable,
and they tend to undergo intramolecular cyclization via
addition of the hydrazone NH group at the carbonyl
group linked to electron-withdrawing polyfluoroalkyl
residue. We failed to effect dehydration of compounds
IIa–IIh by heating in acetic acid, acetic anhydride, or
boiling toluene in the presence of dehydrating agents.
CD3CN
Pyridine-d5
CDCl3
IIg
IIh
DMSO-d6
Acetone-d6
CDCl3
03
21
–
35
19
03
20
13
17
08
18
DMSO-d6
Acetone-d6
CD3OD
–
05
–
CD3CN
07
–
Pyridine-d5
a
The 19F NMR spectrum was recorded in 24 h after dissolution.
group with more than one carbon atom (see Experi-
mental and table).
With a view to examine solvent effect on the ring–
chain isomerism of compounds IIa–IIh, 19F NMR
spectra of imidazotriazines IIa, IId, IIf, and IIh in
CD3CN, CD3OD, and pyridine-d5 were recorded.
19F NMR spectroscopy was selected as the most appro-
priate method for identification of cyclic (B) and open-
chain isomers (A). We found that in all cases open-
chain structure A″ appeared in pyridine-d5. Open-
chain isomers A′ and A″ were present in CD3OD and
CD3CN only for compounds having a polyfluoroalkyl
We can conclude that compounds II in the crystal-
line state have the structure of dihydroimidazotriazines
B which are capable of undergoing ring–chain iso-
merism in solution as a result of cleavage of the C4–N5
bond. Ring–chain transformations are especially typ-
ical of dihydroimidazotriazines having more than one
carbon atom in the polyfluoroalkyl substituent. The
possibility for ring–chain isomerism is determined by
reversible character of nucleophilic addition of the
imidazole NH group at the polyfluoroacyl fragment.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 4 2009

SHCHEGOL’KOV et al.
576
Scheme 3.
H
N
·
·
·
O
O
N
H
RF
N
O
O
N
H
O
RF
N
N
R
O
RF
N
N
R
N
H
N
N
R
N
N
OEt
N
N
·
·
·
O
H
H
COOEt
COOEt
B
N
O
NH
EtO
N
R
N
H
O
RF
O
A
More facile formation of open-chain structures from
dihydroimidazotriazines IIe–IIh may be rationalized
as follows. Longer polyfluoroalkyl groups induce more
negative electrostatic field which favors expulsion of
the neighboring nucleophilic nitrogen atom. Polar sol-
vents such as DMSO-d6, acetone-d6, CD3CN, and
CD3OD, are likely to enhance the effect of electrostatic
field. Pyridine is a fairly strong base (pKa = 5.23 [12])
which is capable of abstracting proton from the hy-
droxy group of dihydroimidazotriazine B, and anionic
intermediate thus formed is stabilized via opening of
the triazine ring (Scheme 3). Therefore, open-chain
structures A are observed in pyridine-d5 for all the
examined compounds, regardless of the length of the
polyfluoroalkyl chain.
Single crystals of compound IIh were obtained by
crystallization from chloroform–hexane (4:1). The
X-ray diffraction data were acquired on an Xcalibur 3
diffractometer equipped with a CCD detector [graphite
monochromator, λ(MoKα) 0.71073 Å, temperature
102(2) K, ψ/ω-scanning]. Correction for absorption
was introduced analytically using a multifaceted crys-
tal model (CrysAlis RED 1.171.29.9). The structure
was solved by the direct method from the Fourier
difference syntheses using SHELXS-97 software [13].
The positions and temperature factors of non-hydrogen
atoms were refined by the least-square procedure in
full-matrix anisotropic approximation using SHELXL-
97 software [13]. Crystallographic data for compound
IIh: C18H13F7N4O4; M 482.32; monoclinic crystals
with the following unit cell parameters: a = 25.033(3),
b = 11.312(3), c = 14.207(3) Å; β = 106.79(7)°; V =
3851.6(6) Å3; Z = 8; dcalc = 1.664 g/cm3; μ =
0.163 mm–1; space group C2/c. Total of 3875 reflection
intensities were measured; number of independent
reflections 2659, R factor 0.040, number of refined
parameters 306. The complete set of crystallographic
data for compound IIh was deposited to the Cam-
bridge Crystallographic Data Centre (entry no. CCDC
688635; www.ccdc.cam.ac.uk/conts/retrieving.html;
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK;
e-mail: deposit@ccdc.cam.ac.uk).
EXPERIMENTAL
The IR spectra were recorded on a Perkin–Elmer
Spectrum One spectrometer with Fourier transform
from samples dispersed in mineral oil or using a dif-
fuse reflectance adapter (DRA). The NMR spectra
were obtained on a Bruker DRX-400 spectrometer at
1
400.13, 100.6, and 376 MHz for H, 13C, and 19F, re-
spectively; the chemical shifts were measured relative
to tetramethylsilane (1H, 13C) or hexafluorobenzene
(19F). The elemental compositions were determined
using a Perkin–Elmer 2400 Series II analyzer. Column
chromatography was performed on Merck 60 silica gel
(0.063–0.200 mm). The melting points were deter-
mined in open capillaries on a Stuart SMP3 melting
point apparatus.
Initial fluorinated 1,3-diketones Ia–Ih were syn-
thesized according to the procedure described in [14].
4-Hydroxy-4-polyfluoroalkyl-1,4-dihydroimid-
azo[5,1-c][1,2,4]triazines IIa–IIh (general proce-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 4 2009

SYNTHESIS AND STRUCTURE OF 4-HYDROXY-4-FLUOROALKYL-...
CDCl3: 1.39 s (9H, CMe3), 1.43 t (3H, CH2CH3, 3JHH
577
dure). A two-necked flask equipped with a stirrer and
=
3
a dropping funnel was charged with 10 mmol of ethyl
5-amino-1H-imidazole-4-carboxylate, a mixture of
3 ml of concentrated hydrochloric acid and 10 ml of
water was added, the mixture was cooled to 0°C, and
a solution of 0.70 g of sodium nitrite in 3 ml of water
was slowly added dropwise under vigorous stirring,
maintaining the temperature at 0°C. The resulting so-
lution of imidazolediazonium salt was added dropwise
to a solution of 4.55 g of sodium acetate and 10 mmol
of 1,3-diketone Ia–Ih in 31 ml of acetone under stir-
ring at 10°C. By the end of the addition procedure,
crystals began to separate from the solution. The
precipitate was filtered off and purified by column
chromatography using chloroform as eluent.
7.1 Hz), 4.43 m (2H, OCH2, JHH = 7.1 Hz), 7.63 br.s
(1H, 6-H), 8.22 br.s (1H, NH), 10.10 br.s (1H, OH); in
DMSO-d6: 1.30 s (9H, CMe3), 1.30 t (3H, CH2CH3,
3
3JHH = 7.0 Hz), 4.30 m (2H, OCH2, JHH = 7.0 Hz),
7.85 br.s (1H, 6-H), 9.30 s (1H, NH), 12.41 s (1H,
3
OH); in acetone-d6: 1.34 t (3H, CH2CH3, JHH
=
=
7.1 Hz), 1.37 s (9H, CMe3), 4.38 m (2H, OCH2, 3JHH
7.1 Hz), 7.77 br.q (1H, 6-H, 5JHF = 1.0 Hz), 8.29 s (1H,
NH), 11.81 br.s (1H, OH). 19F NMR spectrum, δF,
5
ppm, B (100%): in CDCl3: 78.52 d (CF3, JFH
=
0.9 Hz); in DMSO-d6: 83.00 d (CF3, 5JFH = 0.9 Hz); in
5
acetone-d6: 81.40 d (CF3, JFH = 1.0 Hz). Found, %:
C 46.04; H 4.82; F 15.69; N 15.59. C14H17F3N4O4. Cal-
culated, %: C 46.41; H 4.73; F 15.73; N 15.46.
Ethyl 3-acetyl-4-hydroxy-4-trifluoromethyl-1,4-
dihydroimidazo[5,1-c][1,2,4]triazine-8-carboxylate
(IIa). Yield 72%, light brown powder, mp 160–161°C.
IR spectrum (mineral oil), ν, cm–1: 3270, 3170 (NH.,
OH); 1685 br. (C=O); 1610, 1545 (δNH, C=C, C=N);
Ethyl 3-benzoyl-4-hydroxy-4-trifluoromethyl-
1,4-dihydroimidazo[5,1-c][1,2,4]triazine-8-carbox-
ylate (IIc). Yield 62%, yellow crystals, mp 112–
113°C. IR spectrum (mineral oil), ν, cm–1: 3280, 3135
(NH, OH); 1685 br, 1665 (C=O); 1605, 1590, 1550
1
1
(δNH, C=C, C=N); 1180–1150 (C–F). H NMR spec-
1220–1100 (C–F). H NMR spectrum, δ, ppm, isomer
3
trum, δ, ppm, B (100%): in CDCl3: 1.33 t (3H,
B (100%): in CDCl3: 1.44 t (3H, CH2CH3, JHH
=
=
3
3
3
CH2CH3, JHH = 7.1 Hz), 4.36 m (2H, OCH2, JHH
=
7.1 Hz), 2.58 s (3H, Me), 4.45 m (2H, OCH2, JHH
7.1 Hz), 7.65 br.q (1H, 6-H, 5JHF = 0.9 Hz), 7.73 s (1H,
NH), 10.36 br.s (1H, OH); in DMSO-d6: 1.30 t (3H,
CH2CH3, 3JHH = 7.0 Hz), 2.42 s (3H, Me), 4.30 q (2H,
OCH2, 3JHH = 7.0 Hz), 7.89 br.s (1H, 6-H), 9.33 s (1H,
NH), 12.65 s (1H, OH); in acetone-d6: 1.35 t (3H,
CH2CH3, 3JHH = 7.1 Hz), 2.51 s (3H, Me), 4.38 q (2H,
7.1 Hz), 7.50–7.70 m, 7.93–7.95 m (5H, Ph), 7.71 br.s
(1H, 6-H), 8.30 s (1H, NH), 10.54 br.s (1H, OH); in
3
DMSO-d6: 1.30 t (3H, CH2CH3, JHH = 7.1), 4.29 m
3
(2H, OCH2, JHH = 7.1), 7.50–7.76 m (5H, Ph),
7.94 br.s (1H, 6-H), 9.66 s (1H, NH), 12.58 br.s (1H,
OH). 19F NMR spectrum, δF, ppm, B (100%): in
5
3
5
CDCl3: 78.79 d (CF3, JFH = 0.8 Hz); in DMSO-d6:
OCH2, JHH = 7.1 Hz), 7.79 br.q (1H, 6-H, JHF
=
83.22 br.s (CF3). Found, %: C 50.20; H 3.61; F 14.89;
N 14.59. C16H13F3N4O4. Calculated, %: C 50.27;
H 3.43; F 14.91; N 14.66.
1.1 Hz), 8.06 s (1H, NH), 11.91 br.s (1H, OH).
13C NMR spectrum (DMSO-d6), δC, ppm, B (100%):
14.44 (CH2CH3), 26.90 (OCH2), 59.78 (COCH3),
2
79.06 q (C4, JCF = 35.7 Hz), 111.31 (C3), 122.11 q
Ethyl 3-(furan-2-ylcarbonyl)-4-hydroxy-4-tri-
fluoromethyl-1,4-dihydroimidazo[5,1-c][1,2,4]tri-
azine-8-carboxylate (IId). Yield 68%, bright yellow
crystals, mp 167–168°C. IR spectrum (mineral oil), ν,
cm–1: 3265, 3120 (NH, OH); 1695, 1680 (C=O); 1650,
1610, 1565, 1550 (δNH, C=C, C=N); 1220–1180
3
(CF3, JCF = 290.1 Hz), 129.59 (C8), 130.20 (C8a),
131.78 (C6), 161.46 (CO2Et), 192.87 (COCH3).
19F NMR spectrum, δF, ppm: B (100%): in CDCl3:
5
78.57 d (CF3, JFH = 0.9 Hz); in DMSO-d6: 83.17 d
5
(CF3, JFH = 1.0 Hz); in acetone-d6: 81.75 d (CF3,
5
5JFH = 1.1 Hz); in CD3OD: 82.47 d (CF3, JFH
=
1
(C–F). H NMR spectrum, δ, ppm, B (100%): in
3
0.7 Hz); in pyridine-d5: B (91%): 82.13 br.s (CF3); A″
(9%): 88.86 s (CF3). Found, %: C 41.20; H 3.44;
F 17.58; N 17.69. C11H11F3N4O4. Calculated, %:
C 41.26; H 3.46; F 17.80; N 17.50.
CDCl3: 1.44 t (3H, CH2CH3, JHH = 7.1 Hz), 4.44 m
3
3
(2H, OCH2, JHH = 7.1 Hz), 6.66 d.d (1H, 4′-H, J4′,3′
=
3
3.69, J4′,5′ = 1.68 Hz), 7.69 br.s (1H, 6-H), 7.71 d.d
(1H, 3′-H, J3′,4′ = 3.69, J3′,5′ = 0.66 Hz), 7.80 d.d (1H,
5′-H, J5′,4′ = 1.68, J5′,3′ = 0.66 Hz), 8.21 br.s (1H,
NH), 10.28 br.s (1H, OH); in DMSO-d6: 1.31 t (3H,
CH2CH3, JHH = 7.1 Hz), 4.32 m (2H, OCH2, JHH
3
4
3
4
Ethyl 4-hydroxy-3-(2,2-dimethyl-1-oxopropyl)-4-
trifluoromethyl-1,4-dihydroimidazo[5,1-c][1,2,4]tri-
azine-8-carboxylate (IIb). Yield 65%, bright yellow
crystals, mp 75–76°C. IR diffuse reflectance spectrum,
ν, cm–1: 3260, 3145 (NH, OH); 1730, 1685 br (C=O);
1640, 1610, 1550 (δNH, C=C, C=N); 1200–1100
3
3
=
=
=
3
3
7.1 Hz), 6.77 d.d (1H, 4′-H, J4′,3′ = 3.58, J4′,5′
1.68 Hz), 7.50 d.d (1H, 3′-H, J3′,4′ = 3.58, J3′,5′
3
4
0.69 Hz), 7.92 br.s (1H, 6-H), 8.09 d.d (1H, 5′-H,
1
4
(C–F). H NMR spectrum, δ, ppm, B (100%): in
3J5′,4′ = 1.68, J5′,3′ = 0.69 Hz), 9.61 br.s (1H, NH),
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 4 2009

SHCHEGOL’KOV et al.
578
A″ (5%): 1.32 t (3H, CH2CH3, 3JHH = 7.1 Hz), 6.94 t.t
12.61 br.s (1H, OH); in acetone-d6: 1.35 t (3H,
3
3
2
3
CH2CH3, JHH = 7.1 Hz), 4.38 m (2H, OCH2, JHH
=
=
=
(1H, HCF2, JHF = 52.8, JHF = 5.6 Hz), 7.37 s (1H,
2-H), 8.52 s (1H, 1-H), 12.91 br.s (1H, 5-NH); in
acetone-d6: 7.34–7.74 m and 7.86–7.92 m (5H, Ph); B
3
3
7.1 Hz), 6.76 d.d (1H, 4′-H, J4′,3′ = 3.64, J4′,5′
3
4
1.68 Hz), 7.71 d.d (1H, 3′-H, J3′,4′ = 3.64, J3′,5′
5
3
0.69 Hz), 7.83 br.q (1H, 6-H, JHF = 1.2 Hz), 8.00 d.d
(72%): 1.34 t (3H, CH2CH3, JHH = 7.1 Hz), 4.37 m
3
4
3
2
(1H, 5′-H, J5′,4′ = 1.68, J5′,3′ = 0.69 Hz), 8.41 br.s (1H,
(2H, OCH2, JHH = 7.1 Hz), 6.76 t.t (1H, HCF2, JHF
=
NH), 11.92 br.s (1H, OH). 19F NMR spectrum, δF,
3
51.8, JHF = 6.0 Hz), 7.79 br.s (1H, 6-H), 8.50 br.s
(1H, NH), 11.74 br.s (1H, OH); A″ (25%): 1.45 t (3H,
CH2CH3, JHH = 7.1 Hz), 4.44 q (2H, OCH2, JHH
5
ppm, B (100%): CDCl3: 78.89 d (CF3, JFH = 0.7 Hz);
3
3
in DMSO-d6: 83.16 s (CF3); in acetone-d6: 82.04 d
=
=
5
5
2
3
(CF3, JFH = 1.2 Hz); in CD3OD: 82.61 d (CF3, JFH
=
7.1 Hz), 6.86 t.t (1H, HCF2, JHF = 53.2, JHF
5
1.0 Hz); in CD3CN: 82.34 d (CF3, JF5H = 1.0 Hz); in
pyridine-d5: B (97%): 82.46 d (CF3, JFH = 1.1 Hz);
A″ (3%): 88.29 s (CF3). Found, %: C 45.08; H 3.10;
F 15.24; N 15.21. C14H11F3N4O5. Calculated, %:
C 45.17; H 2.98; F 15.31; N 15.05.
6.0 Hz), 7.97 s (1H, 2-H), 8.01 s (1H, 1-H), 13.88 br.s
3
(1H, 5-NH); A′ (3%): 1.25 t (3H, CH2CH3, JHH
=
7.1 Hz), 13.52 br.s (1H, 5-NH). 19F NMR spectrum, δF,
ppm: in CDCl3: B (100%): 26.43 m (2F, HCF2, AB
2
2
3
system, ΔAB = 3.34, JAB = 309.6, JFH = 54.2, JFF
=
3
8.6, JFH = 5.1 Hz), 34.57 m (2F, CF2, AB system,
Ethyl 4-hydroxy-3-(naphthalen-1-ylcarbonyl)-4-
trifluoromethyl-1,4-dihydroimidazo[5,1-c][1,2,4]tri-
azine-8-carboxylate (IIe). Yield 63%, yellow crystals,
mp 137–138°C. IR spectrum (mineral oil), ν, cm–1:
3230, 3100 (NH, OH); 1670 br (C=O); 1635, 1615,
1610, 1560 (δNH, C=C, C=N); 1200–1150 (C–F).
1H NMR spectrum, δ, ppm, B (100%): in CDCl3: 1.31 t
2
ΔAB = 2.42, JAB = 274.2 Hz); in DMSO-d6: B (95%):
2
27.78 m (2F, HCF2, AB system, ΔAB = 2.74, JAB
=
298.9, 2JFH = 51.4, 3JFF = 10.4, 3JFH = 6.3 Hz), 37.54 m
(2F, CF2, AB system, ΔAB = 3.04, 2JAB = 268.0 Hz); A″
2
3
(5%): 25.77 d.t (2F, HCF2, JFH = 52.8, JFF = 7.5 Hz),
41.98 d.m (2F, CF2, JFF = 7.5 Hz); in acetone-d6: B
3
3
(72%): 28.22 m (2F, HCF2, AB system, ΔAB = 3.42,
(3H, CH2CH3, JHH = 7.1 Hz), 4.37 m (2H, CH2CH3,
2
3
3
2JAB = 304.5, JFH = 51.8, JFF = 9.4, JFH = 6.0 Hz),
3JHH = 7.1 Hz), 7.59–7.73 m (3H, Harom), 7.91–8.01 m
(4H, Harom), 8.40 s (1H, NH), 8.53 br.q (1H, 6-H,
5JHF = 0.7 Hz), 10.44 br.s (1H, OH); in DMSO-d6:
2
37.39 m (2F, CF2, AB system, ΔAB = 2.84, JAB
=
269.7 Hz); A″ (25%): 27.99 d.t (2F, HCF2, 2JFH = 53.4,
3JFF = 7.2 Hz), 41.95 m (2F, CF2), 41.93 m (2F, CF2);
3
1.29 t (3H, CH2CH3, JHH = 7.1 Hz), 4.30 m (2H,
2
3
A′ (3%): 26.68 d.t (2F, HCF2, JFH = 52.5, JFF
=
OCH2, 3JHH = 7.1 Hz), 7.61–8.14 m (7H, Harom), 8.40 s
(1H, 6-H), 9.73 br.s (1H, NH), 12.60 br.s (1H, OH).
19F NMR spectrum, δF, ppm, B (100%), in CDCl3:
7.5 Hz), 42.23 m (2F, CF2); in CD3OD: B (91%):
2
2
3
26.88 m (1F, HCF2, JAB = 303.3, JFH = 52.4, JFF
=
9.5 Hz), 29.75 m (1F, HCF2, 2JAB = 303.4, 2JFH = 51.8,
5
78.93 d (CF3, JFH = 0.7 Hz); in DMSO-d6: 83.47 s
3JFF = 10.5 Hz), 36.34 m (1F, CF2, JAB = 267.8 Hz),
2
(CF3). Found, %: C 55.40; H 3.58; F 13.06; N 13.01.
C20H15F3N4O4. Calculated, %: C 55.56; H 3.50;
F 13.18; N 12.96.
2
36.82 m (1F, CF2, JAB = 268.5 Hz); A″ (7%):
2
3
27.36 d.m (2F, HCF2, JFH = 53.4, JFF = 8.3 Hz),
42.03 m (2F, CF2); A′ (2%): 26.35 d.m (2F, HCF2,
2JFH = 53.7 Hz), 42.14 m (2F, CF2); in CD3CN:
B (79%): 27.82 m (2F, HCF2, AB system, ΔAB = 2.57,
Ethyl 3-benzoyl-4-hydroxy-4-(1,1,2,2-tetra-
fluoroethyl)-1,4-dihydroimidazo[5,1-c][1,2,4]tri-
azine-8-carboxylate (IIf). Yield 69%, bright yellow
crystals, mp 159–160°C. IR diffuse reflectance spec-
trum, ν, cm–1: 3255, 3145 (NH, OH); 1675 br (C=O);
1610, 1555 (δNH, C=C, C=N); 1220–1080 (C–F).
1H NMR spectrum, δ, ppm, B (100%): in CDCl3:
2JAB = 306.1, JFH = 51.7, JFF = 9.0 Hz), 36.83 m (2F,
2
3
2
CF2, AB system, ΔAB = 2.07, JAB = 271.4 Hz);
A′ (16%): 27.71 d.m (2F, HCF2, JFH = 53.3, JFF
2
3
=
7.2 Hz), 41.81 m (2F, CF2); A″ (5%): 26.32 d.m (2F,
2
HCF2, JFH = 53.4 Hz), 41.69 m (2F, CF2); in pyri-
3
2
1.33 t (3H, CH2CH3, JHH = 7.1 Hz), 4.37 m (2H,
dine-d5: B (92%): 26.66 m (1F, HCF2, JAB = 295.4,
OCH2, 3JHH = 7.1 Hz), 6.14 t.t (1H, HCF2, 2JHF = 52.4,
3JHF = 5.1 Hz); 7.50–7.54 m, 7.67–7.69 m, and 7.95–
7.97 m (5H, Ph); 7.66 br.s (1H, 6-H), 8.69 s (1H, NH),
10.46 br.s (1H, OH); in DMSO-d6: 4.37 m (2H, OCH2,
3JHH = 7.1 Hz), 7.49–7.75 m (5H, Ph); B (95%): 1.29 t
2JFH = 52.4, 3JFF = 10.3 Hz), 29.23 m (1F, HCF2, 2JAB
=
2
3
300.2, JFH = 51.9, JFF = 11.4 Hz), 35.85 m (1F, CF2,
2
2JAB = 260.5 Hz), 38.38 m (1F, CF2, JAB = 265.7 Hz);
2
A′ (6%): 26.67 d.m (2F, HCF2, JFH = 52.7 Hz),
41.70 m (2F, CF2); A″ (3%): 27.62 d.m (2F, HCF2,
2JFH = 53.0 Hz), 41.50 m (2F, CF2). Found, %:
C 49.61; H 3.48; F 18.20; N 13.55. C17H14F4N4O4. Cal-
culated, %: C 49.56; H 3.41; F 18.34; N 13.52.
3
2
(3H, CH2CH3, JHH = 7.1), 6.87 t.t (1H, HCF2, JHF
=
3
5
51.4, JHF = 6.3), 7.86 d (1H, 6-H, JHH = 2.7 Hz),
9.45 d (1H, NH, JHH = 2.7 Hz), 12.53 s (1H, OH);
5
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 4 2009

SYNTHESIS AND STRUCTURE OF 4-HYDROXY-4-FLUOROALKYL-...
579
Ethyl 3-acetyl-4-heptafluoropropyl-4-hydroxy-
1,4-dihydroimidazo[5,1-c][1,2,4]triazine-8-carbox-
ylate (IIg). Yield 74%, yellow crystals, mp 119–
120°C. IR spectrum (mineral oil), ν, cm–1: 3230, 3140
(NH, OH); 1685, 1665 (C=O); 1605, 1550 (δNH,
8.74 m (5H, Ph); B (97%): 7.70 br.s (1H, 6-H), 8.74 s
(1H, NH), 10.37 br.s (1H, OH); A″ (3%): 7.20 br.s
(1H, 2-H), 8.71 s (1H, 1-H), 12.03 br.s (1H, 5-NH); in
3
DMSO-d6: B (80%): 1.23 t (3H, CH2CH3, JHH
=
3
7.1 Hz), 4.29 q (2H, OCH2, JHH = 7.1 Hz), 7.51–
7.75 m (5H, Ph), 7.93 br.s (1H, 6-H), 9.80 s (1H, NH),
12.64 br.s (1H, OH); A″ (20%): 1.31 t (3H, CH2CH3,
1
C=C, C=N); 1230–1125 (C–F). H NMR spectrum, δ,
ppm: in CDCl3: B (100%): 1.44 t (3H, CH2CH3, 3JHH
=
3JHH = 7.1 Hz), 4.34 q (2H, OCH2, JHH = 7.1 Hz),
3
7.1 Hz), 2.58 s (3H, COCH3), 4.45 m (2H, OCH2,
3JHH = 7.1 Hz), 7.64 br.s (1H, 6-H), 8.07 s (1H, NH),
10.28 br.s (1H, OH); in DMSO-d6: B (62%): 1.30 t
7.34–7.47 m (5H, Ph), 7.39 s (1H, 2-H), 8.50 s (1H,
1-H), 13.23 s (1H, 5-NH); in acetone-d6: 7.34–7.97 m
3
3
(5H, Ph); B (82%): 1.34 t (3H, CH2CH3, JHH
=
(3H, CH2CH3, JHH = 7.0 Hz), 2.42 s (3H, COCH3),
3
7.1 Hz), 4.37 m (2H, OCH2), 7.85 br.s (1H, 6-H),
4.30 m (2H, OCH2, JHH = 7.0 Hz), 7.87 s (1H, 6-H),
8.78 s (1H, NH), 11.97 br.s (1H, OH); A′ (5%): 1.43 t
9.44 s (1H, NH), 12.68 br.s (1H, OH); A′ (3%): 1.41 t
3
3
(3H, CH2CH3, JHH = 7.1 Hz), 4.31 m (2H, OCH2,
(3H, CH2CH3, JHH = 7.2 Hz), 2.53 s (3H, COCH3),
3JHH = 7.1 Hz), 7.85 s (1H, 2-H), 8.19 s (1H, 1-H),
13.95 s (1H, 5-NH); A″ (13%): 1.33 t (3H, CH2CH3,
3
4.40 q (2H, OCH2, JHH = 7.2 Hz), 7.93 s (1H, 2-H),
9.38 s (1H, 1-H), 13.48 s (1H, 5-NH); A″ (35%): 1.27 t
3
3JHH = 7.1 Hz), 4.43 q (2H, OCH2, JHH = 7.1 Hz),
3
(3H, CH2CH3, JHH = 6.7 Hz), 2.11 s (3H, COCH3),
3
7.48 s (1H, 2-H), 8.74 s (1H, 1-H), 12.25 s (1H,
5-NH). 19F NMR spectrum, δF, ppm: in CDCl3:
B (97%): 36.58 m (2F, β-CF2), 40.90 m (2F, α-CF2, AB
system, ΔAB = 1.92, JAB = 286.6 Hz), 81.09 m (3F,
CF3); A″ (3%): 36.60 m (2F, β-CF2), 47.02 m (2F,
α-CF2), 81.27 m (3F, CF3); in DMSO-d6: B (80%):
37.58 m (2F, β-CF2), 44.32 m (2F, α-CF2), 82.41 m
(3F, CF3); A″ (20%): 38.46 m (2F, β-CF2), 50.48 m
(2F, α-CF2), 82.69 m (3F, CF3); in acetone-d6: B (82%):
38.78 m (2F, β-CF2), 41.89 m (2F, α-CF2), 82.99 m
(3F, CF3); A′ (5%): 40.44 m (2F, β-CF2), 51.50 m (2F,
α-CF2), 83.22 m (3F, CF3); A″ (13%): 39.54 m (2F,
β-CF2), 51.21 m (2F, α-CF2), 83.16 m (3F, CF3); in
CD3OD: B (83%): 38.95 m (2F, β-CF2), 44.44 m (2F,
α-CF2), 82.90 m (3F, CF3); A″ (17%): 39.48 m (2F,
β-CF2), 51.10 m (2F, α-CF2), 83.07 m (3F, CF3); in
CD3CN: B (85%): 38.54 m (2F, β-CF2), 43.40 m (2F,
α-CF2), 82.90 m (3F, CF3); A′ (7%): 38.95 m (2F,
β-CF2), 51.34 m (2F, α-CF2), 83.15 m (3F, CF3);
A″ (7%): 39.51 m (2F, β-CF2), 50.93 m (2F, α-CF2),
83.03 m (3F, CF3); in pyridine-d5: B (82%): 37.96 m
(2F, β-CF2), 43.83 m (2F, α-CF2), 82.01 m (3F, CF3);
A″ (18%): 38.41 m (2F, β-CF2), 50.21 m (2F, α-CF2),
82.14 m (3F, CF3). Found, %: C 44.57; H 2.69;
F 27.64; N 11.45. C18H13F7N4O4. Calculated, %:
C 44.82; H 2.72; F 27.57; N 11.62.
4.31 q (2H, OCH2, JHH = 6.7 Hz), 7.70 s (1H, 2-H),
8.46 s (1H, 1-H), 12.94 s (1H, 5-NH); in acetone-d6:
3
B (60%): 1.35 t (3H, CH2CH3, JHH = 7.1 Hz), 2.53 s
3
(3H, COCH3), 4.38 m (2H, OCH2, JHH = 7.1 Hz),
7.79 br.s (1H, 6-H), 7.99 br.s (1H, NH), 11.90 br.s (1H,
OH); A′ (21%): 1.49 t (3H, CH2CH3, 3JHH = 7.1 Hz),
3
2.60 s (3H, COCH3), 4.45 q (2H, OCH2, JHH
=
7.1 Hz), 7.56 br.s (1H, 1-H), 7.99 s (1H, 2-H),
12.10 br.s (1H, 5-NH); A″ (19%): 1.32 t (3H,
3
CH2CH3, JHH = 7.1 Hz), 2.30 s (3H, COCH3), 4.32 q
(2H, OCH2, 3JHH = 7.1 Hz), 7.36 br.s (1H, 1-H), 7.85 s
19
(1H, 2-H), 11.90 br.s (1H, 5-NH). F NMR spectrum,
δF, ppm: in CDCl3, B (100%): 36.01 m (2F, β-CF2),
41.04 m (2F, α-CF2), 81.11 m (3F, CF3); in DMSO-d6:
B (62%): 36.88 m (2F, β-CF2), 43.90 m (2F, α-CF2),
82.44 m (3F, CF3); A′ (3%): 38.39 m (2F, β-CF2),
51.92 m (2F, α-CF2), 81.98 m (3F, CF3); A″ (35%):
38.90 m (2F, β-CF2), 51.44 m (2F, α-CF2), 82.80 m
(3F, CF3); in acetone-d6: B (60%): 38.16 m (2F,
β-CF2), 44.01 m (2F, α-CF2), 83.01 m (3F, CF3);
A′ (21%): 39.74 m (2F, β-CF2), 52.30 m (2F, α-CF2),
83.41 m (3F, CF3); A″ (19%): 40.37 m (2F, β-CF2),
51.91 m (2F, α-CF2), 83.25 m (3F, CF3). Found, %:
C 37.24; H 2.64; F 31.75; N 13.25. C13H11F7N4O4. Cal-
culated, %: C 37.16; H 2.64; F 31.65; N 13.33.
Ethyl 3-benzoyl-4-heptafluoropropyl-4-hydroxy-
1,4-dihydroimidazo[5,1-c][1,2,4]triazine-8-carbox-
ylate (IIh). Yield 70%, yellow crystals, mp 77–78°C.
IR diffuse reflectance spectrum, ν, cm–1: 3250, 3170
(NH, OH); 1670 (C=O); 1605, 1550 (δ NH, C=C,
This study was performed under financial support
by the Russian Foundation for Basic Research (project
no. 09-03-00274a), by the State Program for Support
of Leading Scientific Schools (project no. NSh-
3758.2008.3), by the Ministry of Education and
Science of the Russian Federation, and by the US
Civilian Research and Development Foundation (grant
no. Y3-S-05-15).
1
C=N); 1220–1120 (C–F). H NMR spectrum, δ, ppm:
in CDCl3: 1.37 t (3H, CH2CH3, 3JHH = 7.1 Hz), 4.39 m
3
(2H, OCH2, JHH = 7.1 Hz), 7.51–7.68 m and 8.71–
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 4 2009

SHCHEGOL’KOV et al.
J. Chem. Soc., Perkin Trans. 1, 1987, p. 665; Novin-
580
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