Reactions of 3-(Polyfluoroalkyl)propane-1,2,3-trione-2-oximes with Diaminoarenes

Article abstract of DOI:10.1134/S1070363219030083

Novel quinoxaline derivatives have been synthesized via the reaction of 3-trifhioromethyl-1,2,3-propanetrione-2-oximes with 1,2-diaminobenzene or 2,3-diaminonaphthalene: 2-trifluoromethyl-3-aroylquinoxaline and 2-trifluoromethyl-3-aroylbenzo[g]quinoxaline. Under similar conditions, 3-R^F-1,2,3-propanetrione-2-oximes [R^F = C₃F₇, H(CF₂)₄, C₄F₉, and C₆F₁₃] with the same diaminoarenes have given a mixture of the condensation and fragmentation products in different ratios. The structure of (4-methylphenyl)[3-(tri-fluoromethyl)benzo[g]quinoxalin-2-yl]methanone has been elucidated by means of X-ray diffraction analysis.

Full text of DOI:10.1134/S1070363219030083

ISSN 1070-3632, Russian Journal of General Chemistry, 2019, Vol. 89, No. 3, pp. 416–423. © Pleiades Publishing, Ltd., 2019.
Russian Text © N.S. Boltacheva, P.А. Slepukhin, М.G. Pervova, V.I. Filyakova, V.N. Charushin, 2019, published in Zhurnal Obshchei Khimii, 2019, Vol. 89,
No. 3, pp. 385–393.
Reactions of 3-(Polyfluoroalkyl)propane-1,2,3-trione-2-oximes
with Diaminoarenes
N. S. Boltachevaa, P. А. Slepukhina, М. G. Pervovaa, V. I. Filyakovaa*, and V. N. Charushina
a I.Ya. Postovsky Institute of Organic Synthesis, Ural Branch, Russian Academy of Sciences,
ul. S. Kovalevskoi/Akademicheskaya 22/20, Yekaterinburg, 620990 Russia
*e-mail: filver@mail.ru
Received September 27, 2018; revised September 27, 2018; accepted October 4, 2018
Abstract—Novel quinoxaline derivatives have been synthesized via the reaction of 3-trifluoromethyl-1,2,3-
propanetrione-2-oximes with 1,2-diaminobenzene or 2,3-diaminonaphthalene: 2-trifluoromethyl-3-aroyl-
quinoxaline and 2-trifluoromethyl-3-aroylbenzo[g]quinoxaline. Under similar conditions, 3-RF-1,2,3-propane-
trione-2-oximes [RF = C3F7, Н(CF2)4, C4F9, and C6F13] with the same diaminoarenes have given a mixture of
the condensation and fragmentation products in different ratios. The structure of (4-methylphenyl)[3-(tri-
fluoromethyl)benzo[g]quinoxalin-2-yl]methanone has been elucidated by means of X-ray diffraction analysis.
Keywords: fluorine-containing lithium 1,3-diketonates, 1,2,3-alkanetrione-2-oximes, 2-RF-3-benzoylquino-
xalines, 2-RF-3-aroylbenzo[g]quinoxalines, (4-methylphenyl)[3-(trifluoromethyl)benzo[g]-quinoxalin-2-yl]methanones
DOI: 10.1134/S1070363219030083
1,2,3-Alkanetrione 2-oximes (2-hydroxyimino-1,3-
diketones) are valuable polyfunctional building blocks
for targeted synthesis of many acyclic and heterocyclic
compounds [1]. However, the properties of 3-poly-
fluoroalkyl-1,2,3-alkanetrione-2-oximes 1 are almost
not investigated as the efficient methods for their
synthesis consisting in nitrosation of lithium 3-
(polyfluoroalkyl)-1,3-diketonates 3 with sodium nitrite
in acetic acid was only recently developed [2]1. At the
same time, the reactivity of compounds bearing
fluorinated substituents is substantially different from
this of their nonfluorinated analogs, because of strong
electron-withdrawing effect of the fluorine atom [6, 7].
Our literature analysis has revealed that the known
examples of oximes 1 heterocyclization have been
limited to the reactions of 1a with hydrazine, leading
to the formation of 4-hydroxyimino-5-phenyl-3-tri-
fluoromethylpyrazole [8] or 5-phenyl-3-(trifluoro-
methyl)-1H-pyrazole-4-amine [9] and with 1,2-di-
aminobenzene to give 3-trifluoromethylquinoxaline-2-
one or 2-hydroxy-3-hydroxyimino-4-phenyl-2-trifluoro-
methyl-1H-1,5-benzodiazepine [10]. We have earlier
shown that the reactions of oximation involving
oximes 1 afford 5-hydroxy-5-(polyfluoroalkyl)isoxazol-
4(5H)-one oximes in high yield [11]. Herein we
investigated the reactions of oximes 1a–1f with 1,2-
diaminobenzene 4 and 2,3-diaminonaphtha-lene 5.
Oxime 1 can form several products of condensation
with diaminoarenes 4, 5, due to the possibility of
reaction at the electrophilic centers 1–2, 2–3, 1–3 with
the formation of compounds 6–11 (Scheme 1).
Moreover, various fragmentations can occur in the
course of the reactions, involving the starting oxime 1
and the products of its condensation with 1,2-
diaminoarene. It is known that refluxing of oxime 1а
with 1,2-diaminobenzene 4 in methanol affords
exclusively to 3-trifluoromethylquinoxaline-2-one 12a,
which is indicative of condensation of diaminoarene 4
with the product of fragmentation of oxime 1а.
Carrying out the reaction in boiling diethyl ether has
led to the formation of 2-hydroxy-3-hydroxyimino-4-
phenyl-2-trifluoromethyl-1H-1,5-benzodiazepine 13а
[10] (Scheme 2). There is no other information about
interaction of oximes with diaminoarenes in the
literature.
1
Nitrosation of polyfluoroalkyl-1,3-diketones 2 under similar
conditions results in the formation of hydrates of oximes 1 [3] or
is accompanied by decomposition of the molecule. The only
stable representative of oximes 1, 3-hydroxyimino-4-phenyl-
1,1,1-trifluoromethyl-2,4-butanedione 1a, has been prepared via
this method [4, 5].
416

REACTIONS OF 3-(POLYFLUOROALKYL)PROPANE-1,2,3-TRIONE 2-OXIMES
417
Scheme 1.
RF
R
O
O
OM
2, 3
O
N
N
N
1−2
2−3
1−2
Ar
Ar
NaNO2,
AcOH
RF
O
N
RF
6
9
NOH
O
2
RF
R
1
2−3
4
3
5
N
N
RF
RF
O
O
N
Ar
N
Ar
1
10
7
R
R
1−3
N
N
1−3
OH
N
N
OH
N
N
RF
RF
11
8
M=H (2), Li (3); RF = CF3 (a, b), C3F7 (c), C4F9 (d), H(CF2)4 (e), C6F13 (f); R = Ph (а, c–f), 4-CH3C6H4 (b).
We found that refluxing of oximes 1 with equi-
molar amounts of diaminoarenes 4 or 5 in methanol or
ethanol gave complex mixtures of products, in which
compounds 6–8 and 9–11, respectively, were detected
by the GC–MS method. However, the reaction of
oximes 1a and 1b with diaminoarenes 4 or 5 in glacial
acetic acid at room temperature resulted in
predominant formation of the products of condensation
at electrophilic centers 1-2: 2-RF-3-benzoylquinoxa-
lines 6a,b and 2-RF-3-aroylbenzo[g]quinoxalines 9a,
9b, respectively. Small amounts of compounds 7, 8, 12
(or 10, 11, 18) were also detected in the reaction
mixtures by the GC–MS method. Compounds 6a, 6b
and 9a, 9b were white or light-yellow powders soluble
in diethyl ether, methylene chloride, chloroform, and
ethanol. The choice between the isomeric structures 6
and 7 (or 9 and 10) was made basing on the analysis of
the data of IR and NMR spectroscopy as well as mass
spectrometry. The IR spectra of compounds 6a, 6b and
9a, 9b contain narrow strong bands in the range of
1670–1680 cm–1, characteristic of stretching of С=О
groups adjacent to aryl substituents (a strong absorp-
tion band at 1720–1780 cm–1 is characteristic of the
trifluoroacetyl carbonyl group).
Scheme 2.
H
The mass spectra of compounds 6a, 6b and 9b
contain the peaks of molecular ions М+ with relative
intensity of 6–7%, along with the fragment peaks [M –
ArСО]+, [M – СF3]+, and [M – СF3 – ArСО]+ with
intensity up to 1%. The base peak was that of [ArCO]+
ion. Therefore, fragmentation of molecular ions М+ of
the investigated compounds correspond to the
structures of 2-RF-3-benzoylquinoxalines 6а, 6b and 2-
RF-3-aroylbenzo[g]quinoxalines 9b.
N
O
MeOH
N
RF
12
4
____
1
R
N
N
OH
N
Et2O
OH
13C NMR spectra of compounds 6а, 6b and 9а
contain a singlet of the carbonyl carbon atom at ~191
ppm. For isomers 7а, 7b and 10а, the signal of the
N
H
RF
13
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 89 No. 3 2019

418
BOLTACHEVA et al.
corresponding atoms of the second molecule are
denoted with index “А.” The bond lengths and bond
angles of the two molecules coincided with the
expected values and were pairwise close. The aroyl
fragment in both molecules was practically planar and
turned by 69.6° with respect to the heterocycle plane.
Significantly shortened intermolecular contacts were
not observed in the crystal.
Let us note that the SciFinder and Reaxys databases
did not contain any information about quinoxalines of
the type 6 and 7 containing simultaneously fluoroalkyl
and aroyl substituents. At the same time, quinoxaline
and its derivatives are of great importance. The
quinoxaline ring is present in numerous antibacterial,
antiviral [12], and antituberculosis drugs [13], complex-
forming agents, luminophores [14], dyes, organic
semiconductors [15], and other practically useful
compounds.
General view of the molecule of compound 9b according
X-ray diffraction analysis (50% thermal ellipsoids are
shown).
carbonyl carbon would be a quartet. 19F NMR spectra
of compounds 6а, 6b and 9а showed the CF3 signal at
δ –65 ppm, whereas the CF3С(О) group would give a
signal at δ ~ –73 ppm [2, 3].
Elongation of the fluoroalkyl chain in oximes 1
[RF = C3F7, Н(CF2)4, C4F9, or C6F13] drastically
decreased the selectivity of their reaction with
diaminoarenes 4 or 5, leading to the formation of the
products of condensation and fragmentation in
different ratios (Tables 3 and 4). The amount of the
products of fragmentation was increased when
carrying out the reactions in AcOH at reflux. The GC–
The structure of (4-methylphenyl-[3-(trifluoro-
methyl)benzo[quinoxalin-2-yl]methanone 9b was
unequivocally elucidated by X-ray diffraction analysis
(see figure). The unit cell contained two crystallo-
graphically independent molecules exhibiting similar
geometry. The selected bond lengths and bond angles
are summarized in Tables 1 and 2. The numbers of the
Table 1. Selected bond lengths in molecule 9b
Bond
F1–C15
F2–C15
F3–C15
N1–C2
N1–C14
N4–C3
d, Å
Bond
N4–C5
O1–C16
C2–C15
C3–C2
C14–C5
C3–C16
d, Å
Bond
d, Å
Bond
N4A–C5A
O1A–C16A
C2A–C15A
C2A–C3A
C14A–C5A
C3A–C16A
d, Å
1.329(3)
1.338(3)
1.316(3)
1.301(3)
1.375(3)
1.307(3)
1.380(3)
1.213(3)
1.497(4)
1.439(4)
1.427(3)
1.522(3)
F1A–C15A
F2A–C15A
F3A–C15A
N1A–C2A
N1A–C14A
N4A–C3A
1.324(3)
1.337(3)
1.329(3)
1.296(3)
1.378(3)
1.306(3)
1.376(3)
1.212(3)
1.511(4)
1.437(3)
1.427(3)
1.516(3)
Table 2. Selected bond angles in molecule 9b
Angle
C2 N1 C14
C3N4C5
O1C16C3
O1C16C17
N1C14C5
ω, deg
Angle
N1C14C13
F1C15F2
F3C15F2
F3C15F1
C17C16C3
ω, deg
Angle
ω, deg
Angle
N1AC14AC13A
F1AC15AF2A
F3AC15AF2A
F1AC15AF3A
C17AC16AC3A
ω, deg
119.6(2)
106.3(3)
106.7(2)
107.0(2)
119.3(2)
116.3(2)
117.0(2)
115.8(3)
123.5(3)
120.9(2)
119.7(2)
105.1(2)
106.6(3)
106.8(2)
120.8(2)
C2AN1AC14A
C3AN4AC5A
O1AC16AC3A
O1AC16AC17A
N1AC14AC5A
116.7(2)
117.2(2)
117.0(3)
123.7(2)
120.4(2)
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REACTIONS OF 3-(POLYFLUOROALKYL)PROPANE-1,2,3-TRIONE 2-OXIMES
419
Table 3. GC–MS analysis data for the products of the reaction of oxime 1d with 2,3-diaminobenzene 4
Comp. Content in the Retention time, [M]+, m/z
Characteristic ions, m/z (Irel, %)
no.
mixture, %a
7.3
min
(Irel, %)
16d
11.07
131 (63) 105 (100) [C6H5CO]+, 77 (62) [C6H5]+, 51 (41) [C4H3]+, 38 (5)
[C3H2]+, 27 (3) [HCN]+
14d
11.9
15.03
336 (26) 317 (8) [M – F]+, 297 (0.5) [M – HF2]+, 198(6) [M – F – C2F5]+,
167 (100) [M – C3F7]+, 147 (21) [M – C3F7 – HF]+, 140 (14) [M –
C3F7 – HCN]+, 131 (1) [C3F5]+, 116 (6) [M – C3F7 –HCF2]+, 90 (13)
[C6H4N]+, 69 (11) [CF3]+, 51 (3) [C4H3]+
1d
6d
16.1
13.9
19.29
22.75
395 (4)
219 (0.7) [C4F9]+, 169 (0.3) [C3F7]+, 131 (5) [C3F5]+, 119 (2) [C2F5]+,
105 (100) [C6H5CO]+, 77 (48) [C6H5]+, 69 (11) [CF3]+, 51 (16)
[C4H3]+
433 (3) [M – F]+, 424 (2) [M – CO]+, 347 (0.4) [M – C6H5CO]+,
283 (0.1) [M – C3F7]+, 233 (1) [M – C4F9]+, 205 (0.7) [M – C4F9 –
CO]+, 178 (0.6) [M – C6H5CO – C3F7]+, 147 (2) [M – C6H5CO –
C4F8]+, 128 (3) [M –C6H5CO – C4F9]+, 105 (100) [C6H5CO]+,
77 (39) [C6H5]+, 69 (4) [CF3]+, 51 (8) [C4H3]+
452 (9)
15d
8d
4.7
24.31
25.07
194 (100) 167 (5) [M – HCN]+, 140 (2), [M – 2HCN]+, 104 (5) [C8H8]+,
90 (8) [C7H6]+, 77 (9) [C6H5]+, 63 (11) [C5H3]+, 51 (6) [C4H3]
46.0
467 (39) 450 (100) [M – OH]+, 431 (5) [M – OH – F]+, 262 (20), 231 (36)
[M – C4F9 – OH]+, 205 (15) [M – C4F9 – CNOH]+, 77 (25) [C6H5]+,
69 (30) [CF3]+
а Calculated from the peak areas in the chromatograms using the method of internal normalization.
Table 4. GC–MS analysis data for the products of the reaction of oxime 1c with 2,3-diaminonaphthalene 5
Comp. Content in the
no.
Retention
time, min
[M]+, m/z
(Irel, %)
Characteristic ions, m/z (Irel, %)
mixture, %a
9.5
16c
11.07
131 (63) 105 (100) [C6H5CO]+, 77 (62) [C6H5]+, 51 (41) [C4H3]+, 38 (5)
[C3H2]+, 27 (3) [HCN]+
19c
35.8
20.80
336 (100) 317 (9) [M – F]+, 297 (0.2) [M – HF2]+, 248 (4) [M – F – CF3]+, 217
(60) [M – C2F5]+, 197 (15) [M – C2F5 – HF]+, 190 (11) [M – C2F5 –
HCN]+, 152 (26) [C11H6N]+, 145 (37) [C10H6F]+, 140 (33)
[C10H6N]+, 125 (6) [C10H5]+, 69 (11) [CF3]+, 51 (3) [C4H3]
11c
9c
4.3
27.25
28.01
467 (51) 448 (0.5) [M – F]+, 421 (2) [M – F – HCN], 298 (71) [M – C3F7]+,
271 (84) [M – C3F7 – HCN]+, 140 (100) [C10H6N]+, 77 (23) [C6H5]+,
69 (22) [CF3]+, 51 (7) [C4H3]+
16.3
452 (7)
433 (0.8) [M – F]+, 424 (3) [M – CO]+, 347 (0.5) [M – C6H5CO]+,
283 (2) [M – C3F7]+, 207 (1) [M – C3F7 – C6H4]+, 178 (3) [M – C3F7 –
COC6H5]+, 152 (8) [M – C3F7 – C6H5CO – HCN]+, 125 (3) [C10H5]+,
105 (100) [C6H5CO]+, 77 (39) [C6H5]+, 51 (5) [C4H3]+
20c
34.1
31.56
244 (100) 217 (3) [M – HCN]+, 190 (1), [M – 2HCN]+, 140 (28) [C10H6N]+,
122 (23) [C10H2]+, 114 (25) [C9H6]+, 77 (7) [C6H5]+, 63 (5) [C5H3]+,
51 (4) [C4H3]+
а Calculated from the peak areas in the chromatograms using the method of internal normalization.
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420
BOLTACHEVA et al.
Scheme 3.
H
N
H
N
N
N
R
RF
R−C(O)−CN
R
N
N
16
17
15
14
H
N
H
N
H
N
O
N
N
R
RF
R
N
RF
N
N
19
20
21
18
MS analysis showed the presence of condensation
products 6–8 in the products of the reaction of oximes
1c–1f with 1,2-diaminobenzene 4 (Scheme 1), along
with quinoxalones 12 (Scheme 2), benzimidazoles 14
and 15, ketonitriles RC(O)CN 16, and quinoxalines
172 (Scheme 3). Similar products composition was
found for the reactions of oximes 1c–1f with 2,3-
EXPERIMENTAL
Melting points were determined using Boetius and
Stuart SMP3 instruments. IR spectra were recorded for
solid samples using a Perkin-Elmer Spectrum One FT-
IR spectrometer using a diffuse reflectance unit (DRA)
1
over the 400–4000 cm–1 range. Н, 13С, and 19F NMR
diamino-naphthalene
5:
2-RF-3-aroylbenzo[g]
spectra were registered using a Bruker AVANCE-500
spectrometer, TMS and C6F6 were used as internal
references. Elemental analysis was performed using a
Perkin Elmer PE 2400 elemental analyzer.
quinoxalines 9, naphthodiazepines 11 (Scheme 1),
benzo[g]quinoxalones 18, naphthoimidazoles 19, 20,
ketonitriles RC(O)CN 16, and benzo[g]quinoxalines
213 were identified (Scheme 3).
The reaction products were identified by means of
Trace GC Ultra DSQ II gas chromatography–mass
spectrometer equipped with a Thermo TR-5ms
capillary column (30 m×0.25 mm×0.25 μm,
polymethylsiloxane, 5% of phenyl groups) and
quadruple mass detector. Scanning of the total ionic
current over the 20–1000 Da mass range in electronic
ionization mode (70 eV) was performed. Other
conditions were as follows: starting temperature of the
column 40°С, exposure for 3 min, heating at 10°С/min
to 280°С; temperature of injector 250°С, temperature
of detector 200°С, temperature of transition chamber
200°С; carrier gas: helium, flow splitting 1 : 50, flow
rate 1.0 mL/min.
The major products were isolated from some of the
mixtures obtained upon the reaction of oximes 1c–f
with diaminoarenes 4 and 5. For example, refluxing of
oxime 1e with 1,2-diaminobenzene 4 in the 1 : 1
mixture of Et2O and EtOH gave 3-RF-quinoxaline-2-
one 12e as the major product, in line with the data
from Ref. [4]. Diazepine 8d and benzimidazole 14d
were isolated from the products of the reaction of
oxime 1d with 1,2-diaminobenzene 4 (Table 3). The
formation of hydrates of benzo- and naphthodiazepines
9 and 11 was not observed in the considered reactions.
In summary, the reactions of 3-polyfluoroalkyl-
1,2,3-alkanetrione 2-oximes with 1,2-diamino-benzene
and 2,3-diaminonaphthalene were investigated, and
new quinoxaline derivatives were obtained.
X-Ray diffraction analysis was performed using an
Xcalibur 3 automated single-crystal X-ray diffracto-
meter [MoKα-radiation, graphite monochromator, ω-
scanning with step of 1° at T = 295(2) K]. the
empirical absorption correction was applied. The
structure was solved and refined using Olex2 software
package [18]: the structure was solved using Superflip
program [19] and refined by full-matrix least square
method over F2 using ShelXL program [20]. The
refinement was performed under anisotropic approxi-
2
Apparently, imidazoles 14 and 15 were the products of
transformation of 1,5-diazepines 8 in acidic medium [16, 17].
Quinoxalines 17 were the products of the reaction of ketonitriles
16 with 1,2-diaminobenzene.
3
Probably, naphthoimidazoles 19 and 20 are the products of
transformation of naphthodiazepines 11 in acidic medium
[16, 17]. Benzo[g]quinoxalines 21 are the products of the
reaction of ketonitriles 16 with 2,3-diaminonaphthalene.
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REACTIONS OF 3-(POLYFLUOROALKYL)PROPANE-1,2,3-TRIONE 2-OXIMES
421
mation for nonhydrogen atoms. Hydrogen atoms were
0.7 Hz), 7.48 d. d. d (1Н, 3JНН = 8.2, 3JНН = 7.0, 4JНН
=
=
placed in the calculated positions and refined using the
rider model. Monocrystals of compound 9b were ob-
tained by crystallization from CHCl3. C21H13F3N2O, M =
366.33, monoclinic, a = 7.9988(7) Å, b = 36.992(2) Å,
c = 11.8595(7) Å, β = 91.304(6)°, V = 3508.2(4) Å3,
space group P21/n, Z = 8, μ(MoKα) = 0.109 mm–1,
scattering angle 4.76° < 2θ < 52.74°, 12867 total
reflections including 6847 independent reflections
(Rint = 0.0353), 3567 of them with I > 2σ(I).
Refinement parameters: R1 = 0.1218, wR2 = 0.1391 (all
data), R1 = 0.0545, wR2 = 0.1075 [I > 2σ(I)], goodness-
of-fit factor GooF = 1.010. Δρē = 0.13/–0.17 ē Å–3. The
crystallographic data were deposited at the Cambridge
Crystallographic Data Center CCDC 1882664 and are
freely available via www.ccdc.cam.ac.uk/data_request/cif.
0.9 Hz), 7.73 d. d. d (1Н, 3JНН = 7.0, 3JНН = 8.2, 4JНН
3
4
0.7 Hz), 8.01 d. d (1Н, JНН = 8.2, JНН = 0.9 Hz) Ph],
12.69 s (1Н, NН). GC–MS (EI, C2H5OH, TIC): m/z
(Irel, %): 346 [M]+ (37), 327 [M – F]+ (7), 195 [M –
HC3F6]+ (100), 167 [M – HC3F6 – CO]+ (68), 147 [M –
HC3F6 – CO – HF]+ (34), 140 [M – HC3F6 – CO –
HCN]+ (18), 102 [C7H4N]+ (19), 90 [C6H4N]+ (34), 69
[CF3]+ (6), 63 [C5H3]+ (13), 51 [HCF2]+ (13), 39 [HF2]+
(4). Found, %: С 41.58; H 1.45; N 7.97; F 43.62.
С12Н6F8N2O. Calculated, %: С 41.64; H 1.75; N 8.09;
F 43.90.
General procedure of the reaction of oximes 1а–
1f with 1,2-diaminobenzene 4 and 2,3-diamino-
naphthalene 5. Equimolar amounts of oxime 1 and
1,2-diaminobenzene 4 or 2,3-diaminonaphthalene 5
were dissolved in glacial acetic acid and kept at room
temperature until the starting compounds disappeared
(TLC monitoring). The reaction mass was poured into
the water, extracted with methylene chloride, and
filtered through the layer of silica. The solvent was
evaporated, the residue was crystallized from the
mixture of methylene chloride and hexane (1 : 3). In
some cases, the product was additionally purified by
column chromatography (eluent: methylene chloride).
Oximes 1а–1f were obtained via nitrosation of the
corresponding lithium 3-(polyfluoroalkyl)-1,3-diketo-
nates with sodium nitrite in acetic acid [2]. The purity
of the products was monitored by TLC on Sorbfil plates
(UV-254, eluent CHCl3). The plates were visualized
using UV light and an aqueous solution of Cu(OAc)2.
4,4,5,5,6,6,6-Heptafluoro-1-phenyl-1,2,3-hexa-
trione-2-oxime 1с was obtained as described else-
where [2] from 2.0 g (6.0 mmol) of lithium diketonate
3с, 9 mL of acetic acid, and 0.48 g (6.9 mmol) of
sodium nitrite, with 1.85 g (89.4%) yield. mp 126–
127oС. IR spectrum, ν, cm–1: 1129 s (CF), 1193 s (CF),
1232 m (CF), 1652 s (C=O), 1713 s (C=O), 3271 br
Phenyl-[3-(trifluoromethyl)-2-quinoxalinyl]me-
thanone (6a) was obtained from 0.33 g (1.3 mmol) of
oxime 1a and 0.15 g (1.3 mmol) of 1,2-di-
aminobenzene 4. Yield 0.19 g (48.7%), mp 78–79°C, tr
23.02 min. IR spectrum, ν, cm–1: 1169 s (CF), 1186 s
1
(NOH). H NMR spectrum, DMSO-d6, δ, ppm: 7.60–
7.66 m (2Н, Нm); 7.76–7.80 m (1Н, Нp), 7.82–7.86 m
(2Н, Но), 14.52 s (1Н, ОН). 19F NMR spectrum
(DMSO-d6), δF, ppm: –125.03 to –124.99 m (2F, CF2),
–114.93 to –114.82 m (2F, CF2), –80.29 t (3F, CF3,
(CF), 1235 m (CF), 1596 s (C=N), 1676 vs (C=O). H
1
NMR spectrum, CDCl3, δ, ppm: 7.48–7.54 m (2Н),
7.64–7.69 m (1Н), 7.90–8.01 m (4Н), 8.18–8.23 m
(1Н), 8.28–8.33 m (1Н). 13C NMR spectrum, CDCl3,
4
1
3JFF = 8.96, JFF = 2.20 Hz). Found, %: С 42.08; H
δ, ppm: 120.73 q (CF3, JCF = 276.0 Hz), 128.74,
1.91; N 4.02; F 38.34. С12Н6F7NO3. Calculated, %: С
41.76; H 1.75; N 4.06; F 38.53.
129.52, 129.93, 130.56, 132.46, 133.20, 134.47,
134.71, 140.40, 141.03 q (CCF3, JCF = 36.4 Hz),
2
141.35, 149.13, 191.18 (C=O). 19F NMR spectrum,
CDCl3: δF –64.59 ppm. GC-MS (EI, in C2H5OH, TIC):
m/z (Irel, %): 302 [M]+ (7), 283 [M – F] (<1), 274 [M –
CO]+ (4), 233 [M – CF3]+ (4), 197 [M – C6H5CO]+
(<1), 128 [M – CF3 – C6H5CO]+ (1), 105 [C6H5CO]+
(100), 77 [C6H5]+ (56), 69 [CF3]+ (4), 51 [C4H3]+ (14).
Found, %: С 63.57; H 3.07; N 9.47; F 18.39.
С16Н9F3N2O. Calculated, %: С 63.58; H 3.00; N 9.27;
F 18.86.
3-(1,1,2,2,3,3,4,4-Octafluorobutyl)quinoxalin-2-
one (12e). A solution of 0.4 g (1.1 mmol) oxime 1e
and 0.12 g (1.1 mmol) of 1,2-diaminobenzene 4 in
10 mL of the Et2O : EtOH mixture (1 : 1) was refluxed
for 2 h and cooled to room temperature, hexane was
added, the formed precipitate was filtered and
crystallized from methylene chloride. Yield 0.32 g
(84.2%), mp 111°C, tr 21.98 min. IR spectrum, ν, cm–1:
1128 s (CF), 1168 s (CF), 1278 m (CF), 1674 v. s
(C=O), 1612 s (C=N), 2896 w (NH). 1H NMR
(4-Methylphenyl)-{3-(trifluoromethyl)-2-quino-
xalinyl}methanone (6b) was obtained from 0.2 g
(0.8 mmol) of oxime 1b and 0.083 g (0.8 mmol) of 1,2-
spectrum, CDCl3, δ, ppm: 6.30 t. t [1H, H(CF2)4, 2JH F
=
=
3
3
4
51.9, JHF = 4.4 Hz, 7.44 d. d (1H, JНН = 8.2, JНН
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422
BOLTACHEVA et al.
diaminobenzene 4. Yield 0.16 g (64%), mp 108–109°C,
tr 24.22 min. IR spectrum, ν, cm–1: 1182 s (CF), 1239 s
(CF), 1282 m (CF), 1604 m (C=N), 1678 s (C=O). H
CN]+ (7), 119 [CH3С6Н4CO]+ (100), 91 [CH3С6Н4]+,
65 [C5H5]+ (11), 51 [HCF2]+ (1). Found, %: С 68.82; H
3.35; N 7.71; F 15.07. С21Н13F3N2O. Calculated, %: С
68.85; H 3.57; N 7.65; F 15.56.
1
NMR spectrum, CDCl3, δ, ppm: 2.45 s (3H, CH3),
[7.30 d (2Н, 3JHH = 8.1 Hz), 7.81 d (2Н, 3JHH = 8.1 Hz)
Ar], [(7.95–8.01 m (2Н), 8.17–8.23 m (1Н), 8.28–8.33
The reaction of oxime 1c with 2,3-
diaminonaphthalene 5 gave a mixture of products 16,
19c, 11c, 9c, 20c (GC–MS data) (Table 4).
m (1Н), quinoxaline ring]. 13C NMR spectrum, CDCl3,
1
δC, ppm: 21.86; 95.74; 120.75 q (CF3, JCF
=
3-Hydroximino-2-(1,1,2,2,3,3,4,4,4-nonafluoro-
butyl)-4-phenyl-3Н-1,5-benzodiazepin-3-one (8d)
was obtained from 0.3 g (0.76 mmol) of oxime 1d and
0.082 g (0.76 mmol) of 1,2-diaminobenzene 4. Column
chromatography gave 0.1 g (28%) of compound 8d
and 0.06 g (23%) of benzimidazole 14d. mp 142–147°C.
IR spectrum, ν, cm–1: 1129 s (CF), 1193 s (CF), 1232
m (CF), 1450 m (C=N), 1572 s (C=N), 3134 br (OH).
1H NMR spectrum, CDCl3, δ, ppm: [7.39–7.46 m
(2Н), 7.48–7.57 m (3Н)] Ph, 7.60–7.77 m (2Н), 7.89 s
276.1 Hz), 129.50, 129.53, 129.93, 130.70, 133.34,
133.13, 140.38, 141.04 q (CCF3, JCF = 36.3 Hz),
2
141.41, 145.75, 149.40, 190.85 (C=O). 19F NMR
spectrum (CDCl3): δF –64.63 ppm. GC-MS (EI, in
C2H5OH, TIC): m/z (Irel, %): 316 [M]+ (6), 301 [M –
CH3]+ (2), 288 [M – CO]+ (1), 247 [M – CF3]+ (1), 197
[M – CH3C6H4CO]+ (1), 128 [M – CF3 – CH3C6H4CO]+
(1), 119 [CH3C6H4CO]+ (100), 91 [CH3C6H4]+ (33), 69
[CF3]+ (3), 65 [C5H5]+ (12), 51 [HCF2]+ (3). Found, %:
С 64.54; H 3.51; N 8.78; F 17.69. С17Н11F3N2O.
Calculated, %: С 64.56; H 3.51; N 8.86; F 18.02.
3
(1Н, ОН), 8.06 d (2Н, JHH = 7.3 Hz). Found, %: С
48.67; H 2.15; N 9.01; F 36.25. С19Н10F9N3O.
Calculated, %: С 48.84; H 2.16; N 8.99; F 36.59.
(4-Phenyl)-{3-(trifluoromethyl)benzo[g]quino-
xalin-2-yl}methanone (9a) was obtained from 0.25 g
(1.0 mmol) of oxime 1a and 0.16 g (1.0 mmol) of 2,3-
diaminonaphthalene 5. Yield 0.2 g (57%), mp 158–
159°C. IR spectrum, ν, cm–1: 1126 s (CF), 1190 s (CF),
1202 m (CF), 1596 m (C=N), 1673 s (C=O). 1H NMR
spectrum, CDCl3, δ, ppm: 7.49–7.57 m (2Н), 7.64–
The reaction of oxime 1e with 2,3-diamino-
naphthalene 5, according to GC–MS data, gave a
complex mixture, the major components being 2-
(1,1,2,2,3,3,4,4-octafluorobutyl)naphthoimidazole 19e
and (4-phenyl)[3-(1,1,2,2,3,3,4,4-octafluorobutyl)benzo-
[g]quinoxalin-2-yl]methanone 9e. 2-(1,1,2,2,3,3,4,4-
Octafluorobutyl)naphthoimidazole (19e) was iso-
lated by preparative column chromatography, mp 215–
217°C, tr 23.31 min. IR spectrum, ν, cm–1: 1143 s (CF),
1170 s (CF), 1274 m (CF), 1476 m (C=N), 3040–2865
br (NH). GC-MS (EI, in CHCl3, TIC): m/z (Irel, %):
368 [M]+ (8), 349 [M – F]+ (1), 317 [M – HCF2]+ (<1),
297 [M – HCF2 – HF]+ (<1), 268 [M – 2CF2]+ (2), 248
[M – 2CF2 – HF]+ (4), 217 [M – HC3F6]+ (30), 197 [M –
HC3F6 – HF]+ (9), 190 [M – HC3F6 – HCN]+ (6), 152
[C11H6N]+ (19), 145 [C10H6F]+ (27), 140 [C10H6N]+ (41),
125 [C10H5]+ (7), 113 [C9H5]+ (26), 69 [CF3]+ (36), 51
[HCF2]+ (100), 39 [HF2]+ (5).
3
7.72 m (3Н), 8.00 d (2Н, JHH 7.6 Hz), 8.11–8.21 m
(2Н), 8.77 s (1Н), 8.9 s (1Н). 13C NMR spectrum,
CDCl3, δс, ppm: 98.1, 120.67 q (CF3, 1JCF = 276.2 Hz),
128.25, 128.50, 128.76, 128.84, 129.19, 130.67, 134.47,
134.73, 135.08, 135.59, 136.03, 136.72, 141.51 q
2
(CCF3, JCF = 36.4 Hz), 148.82, 191.20 (C=O). 19F
NMR spectrum (CDCl3), δF –64.83 ppm. Found, %: С
67.99; H 3.24; N 7.89; F 15.89. С20Н11F3N2O. Cal-
culated, %: С 68.18; H 3.15; N 7.95; F 16.18.
(4-Methylphenyl)-{3-(trifluoromethyl)benzo[g]-
quinoxalin-2-yl}methanone (9b) was obtained from
0.2 g (0.77 mmol) of oxime 1b and 0.12 g (0.77 mmol)
of 2,3-diaminonaphthalene 5. Yield 0.16 g (57%), mp
157.5–158.5оС, tr 31.23 min. IR spectrum, ν, cm–1:
1138 s (CF), 1185 s (CF), 1204 m (CF), 1604 m
The reaction of oxime 1f with 2,3-diamino-
naphthalene 5, according to GC–MS data, gave a
mixture of products 9f, 11f, 19f, 20f, 21f, from which
0.31 g (66%) of 2-(1,1,2,2,3,3,4,4,5,5,6,6,6-trideca-
fluorohexyl)naphthoimidazole (19f) was isolated, mp
148–149оС, tr 22.32 min. IR spectrum, ν, cm–1: 1144 s
(CF), 1202 s (CF), 1238 m (CF), 1479 m (NH), 1588
w (C=N), 3040–2615 br (NH). GC–MS (EI, in
C2H5OH, TIC): m/z (Irel, %): 486 [M]+ (4), 467 [M – F]+
(<1), 367 [M – C2F5]+ (<1), 347 [M – C2F5 – HF]+ (<1),
317 [M – C3F7]+ (2), 298 [M – C3F7 – F]+ (4), 278 [M –
1
(C=N), 1672 s (C=O). H NMR spectrum, CDCl3, δ,
ppm: 2.47 s (3H, CH3), [7.33 d (2H, 3JHH = 8.1 Hz),
7.89 d (2H, 3JHH = 8.1 Hz), С6Н4], [7.70 m (2Н), 8.14
m (2Н), 8.24 m (2Н)], 8.79 s (1Н)], 8.91 s (1Н) quino-
xaline]. 19F NMR spectrum (CDCl3), δF –64.93 ppm.
GC-MS (EI, in C2H5OH, TIC): m/z (Irel, %): 366 [M]+
(7), 351 [M – CH3]+ (1), 338 [M – CO]+ (2), 297 [M –
CF3]+ (1), 247 [M – CH3С6Н4CO]+ (1), 178 [M –
CH3С6Н4CO – CF3]+ (2), 152 [M – CH3С6Н4CO – CF3 –
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REACTIONS OF 3-(POLYFLUOROALKYL)PROPANE-1,2,3-TRIONE 2-OXIMES
423
C3F7 – HF2]+ (1), 248 [M – C4F9 – F]+ (5), 217 [M –
C5F11]+ (41), 197 [M – C5F11 – HF]+ (11), 190 [M –
C5F11 – HCN]+ (6), 152 [C11H6N]+ (21), 145 [C10H6F]+
(34), 140 [C10H6N]+ (39), 125 [C10H5]+ (6), 119 [C2F5]+
(31), 113 [C9H5]+ (18), 69 [CF3]+ (100), 50 [CF2]+ (7),
39 [HF2]+ (5).
7. Kirsch, P., Modern Fluoroorganic Chemistry:
Synthesis, Reactivity, Applications, Weinheim: Wiley-
VCH, 2004.
8. Skryabina, Z.E., Burgart, Y.V., and Saloutin, V.I., Russ.
J. Org. Chem., 1997, vol. 33, p. 392.
9. Emmadi, N.R., Bingi, C., Kotapalli, S.S., Ummanni, R.,
Nanubolu, J.B., and Atmakur, K., Bioorg. Med. Chem.
Lett., 2015, vol. 25, no. 15, p. 2918. doi 10.1007/s12272-
016-0882-x
FUNDING
10. Burgart, Y.V., Kuzueva, O.G., Kodess, M.I., and
Saloutin, V.I., Russ. J. Org. Chem., 1998, vol. 34,
p. 375.
This study was performed with financial support
from the Russian Foundation for Basic Research
(project 18-03-00112 А) in the scope of the State Task
no. 0398-2018-0054, using the equipment of the
Center for Collective Usage “Spectroscopy and
analysis of organic compounds.”
11. Palysaeva, N.V., Boltacheva, N.S., Slepukhin, P.A.,
Pervova, M.G., Filyakova, V.I., Sheremetev, A.B., and
Charushin, V.N., Mendeleev Commun., 2018, vol. 28,
p. 126. doi 10.1016/j.mencom.2018.03.003
12. USSR Patent no. 1037644, 1993.
CONFLICT OF INTEREST
No conflict of interest was declared by authors.
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