Generation of 1-aryl-3-methoxycarbonylnitrilimines and their reaction with halogen-containing unsaturated compounds

Article abstract of DOI:10.1007/s11172-012-0155-x

Thermal decomposition of 1-(4-methoxyphenyl)- and 1-(4-fluorophenyl) hepta(methoxycarbonyl)-3a,7a-dihydroindazoles at 135 C in the presence of allyl or propargyl halides leads to the elimination of hexamethyl benzenehexacarboxylate and the formation of the corresponding pyrazolines or pyrazoles as the products of 1,3-dipolar cycloaddition of 1-aryl-3- methoxycarbonylnitrilimines to the multiple bonds of the substrates used. In the case of vinyl halides, the products of the target reactions are either obtained in low yields or nonexistent, with a side conversions taking place instead. Thus, for example, in the case of 1,1-dichloro-4-methylpenta-1,3-diene, besides hexamethyl benzenehexacarboxylate, 3,5,5-trichloro-2-methylpent-4-en-2-ol and arylchlorohydrazones MeO₂CC(Cl)=N-NHAr were unexpectedly isolated as the main products, as well.

Full text of DOI:10.1007/s11172-012-0155-x

Russian Chemical Bulletin, International Edition, Vol. 61, No. 6, pp. 1138—1147, June, 2012
1138
Generation of 1ꢀarylꢀ3ꢀmethoxycarbonylnitrilimines
and their reaction with halogenꢀcontaining unsaturated compounds
Yu. V. Tomilov, D. N. Platonov, G. P. Okonnishnikova, R. A. Novikov, and N. V. Volchkov
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences,
47 Leninsky prosp., 119991 Moscow, Russian Federation.
Fax: +7 (499) 135 6390. Eꢀmail: tom@ioc.ac.ru
Thermal decomposition of 1ꢀ(4ꢀmethoxyphenyl)ꢀ and 1ꢀ(4ꢀfluorophenyl)hepta(methꢀ
oxycarbonyl)ꢀ3a,7aꢀdihydroindazoles at 135 C in the presence of allyl or propargyl halides
leads to the elimination of hexamethyl benzenehexacarboxylate and the formation of the correꢀ
sponding pyrazolines or pyrazoles as the products of 1,3ꢀdipolar cycloaddition of 1ꢀarylꢀ3ꢀ
methoxycarbonylnitrilimines to the multiple bonds of the substrates used. In the case of vinyl
halides, the products of the target reactions are either obtained in low yields or nonexistent,
with a side conversions taking place instead. Thus, for example, in the case of 1,1ꢀdichloroꢀ4ꢀ
methylpentaꢀ1,3ꢀdiene, besides hexamethyl benzenehexacarboxylate, 3,5,5ꢀtrichloroꢀ2ꢀmeꢀ
thylpentꢀ4ꢀenꢀ2ꢀol and arylchlorohydrazones MeO2CC(Cl)=N—NHAr were unexpectedly isoꢀ
lated as the main products, as well.
Key words: 3a,7aꢀdihydroindazoles, nitrilimines, pyrazolines, pyrazoles, hydrazones, 1,3ꢀdiꢀ
polar addition, thermolysis.
Nitrilimines belong to the class of highly reactive
as well, which were the products of allylic migration of the
proton to the nitrogen atom. The reaction of dihydroindꢀ
azoles 1 with tetramethylethylene was even more compliꢀ
cated:15 in this case, substituted pyrazolinecarboxylates 5
unexpectedly turned out to be the main reaction products,
which were obtained, probably, due to the involvement
H2O providing the incorporation of one additional oxygen
atom into the structure of the products (Scheme 1).
Since the degree of substitution at the double bonds in
unsaturated substrates influenced both the character of the
compounds formed and the regioselectivity of the addiꢀ
tion of nitrilimines,15,16 it seemed interesting to study the
behavior in this process of halogenꢀcontaining unsaturatꢀ
ed compounds with halogen atoms of different mobility.
1,3ꢀdipoles and like aliphatic diazo compounds are used
in the 1,3ꢀdipolar cycloaddition reaction to unsaturated
compounds, which lead to the formation of pyrazolines,
pyrazoles, and other heterocyclic compounds.1—5 Among
various approaches to the generation of nitrilꢀ
imines, 1,3ꢀdehydrochlorination of Nꢀarylchlorohydrꢀ
azones, in particular, hydrazonoyl chlorides of the type
MeO2C(Cl)C=N—NHAr, upon the action of triethylꢀ
amine6—10 or silver salts,10—14 is lately most widely used in
the synthetic practice. Because of specifics of the electron
structure, nitrilimines can display ambiphilic character
and react at the multiple bonds of unsaturated compounds
containing both electronꢀwithdrawing and electronꢀdoꢀ
nating substituents.2—4,12 In most cases, the cycloaddiꢀ
tion of nitrilimines to the unsymmetrically substituted
multiple bonds leads to the formation of both regioꢀ
isomers.2,6,10,12
Recently, we have shown for the first time15,16 that
thermal decomposition of 1ꢀarylhepta(methoxycarbonyl)ꢀ
3a,7aꢀdihydroindazoles 1, going with elimination of hexꢀ
amethyl benzenehexacarboxylate, also allows one to genꢀ
erate the intermediates, which can be intercepted in the
presence of unsaturated substrates to form 1ꢀarylꢀ3ꢀ
(methoxycarbonyl)nitrilimines 2. In this case, the use of
methylꢀcontaining alkenes and dienes as the interceptors
of nitrilimines led, besides the corresponding pyrazolines
3 (the 1,3ꢀdipolar cycloaddition products), to the isolaꢀ
tion of hydrazones of 2ꢀoxoalkeneꢀ1ꢀcarboxylic acids 4,
Results and Discussion
Heptamethyl 1ꢀ(4ꢀmethoxyphenyl)ꢀ (1a) and 1ꢀ(4ꢀfluꢀ
orophenyl)ꢀ3a,7aꢀdihydroindazoleheptacarboxylates (1b)
have been chosen as the source of nitrilimines, whereas
alkenes, acetylenes, and dienes containing halogen atoms
either at the double bond or in the allylic(propargylic)
position were our unsaturated substrates. The experiments
were performed in sealed tubes under inert atmosphere by
heating dihydroindazoles 1 with 6—10ꢀfold molar excess
of unsaturated compounds in a 1,4ꢀdioxane solution at
135 C for 8—10 h.
Thermolysis of dihydroindazole 1a in the presence
of allyl bromide or propargyl chloride leads to the inꢀ
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1129—1138, June, 2012.
1066ꢀ5285/12/6106ꢀ1138 © 2012 Springer Science+Business Media, Inc.

Reactions of nitrylimines with haloalkenes
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
1139
Scheme 1
E = CO2Me, R = C6H4OMe
terception of nitrilimine 2a by the multiple bonds of
the substrates by the type of 1,3ꢀdipolar addition and
obtaining regioisomeric (halomethyl)pyrazolines 6 and 7
or pyrazoles 8a and 9 in 65—70% total yields (Scheme 2).
In both cases, the cycloaddition proceeds with a predꢀ
ominant formation of 3,5ꢀdisubstituted regioisomers 6
or 8a, in which the halomethyl group occupies position
neighboring to the nitrogen atom of the heterocycle.
In the case of allyl bromide, besides pyrazolines,
5ꢀ(bromomethyl)pyrazole 8b was also isolated, which
resulted from the partial oxidation of the pyrazoline
ring. This is actually characteristic enough of other pyrꢀ
azolines obtained under such reaction conditions,15
but we did not observe the products of insertion of the
Scheme 2

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Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
Tomilov et al.
Scheme 3
X = OMe (a), F (b)
2
nitrilimine fragment into the C—Hal bonds in any of the
experiments.
tet with the spinꢀspin coupling constant JC,F ~40 Hz,
whereas the atoms C(5), at  136.2 with 2JC,F  3 Hz. On
the contrary, in isomers 12a,b the atoms C(4) resonate at
 114.5 in pyrazole 12a and  119.4 in pyrazole 12b, but
rather with small spinꢀspin coupling constant, whereas
the atoms C(5), at  131—132 with the spinꢀspin coupling
constant 2JC,F ~40 Hz. For all the compounds, the signal
for the atom C(3) does not virtually change and appears at
 140.8—141.5.
Compounds 6—9 were isolated from the reaction mixꢀ
tures in the individual states by column chromatography
on silica gel and the main reaction products, pyrazoline 6
and pyrazole 8a, were additionally recrystallized from
CCl4. The regioisomers 6 and 7 were assigned based on
1
the chemical shifts for the fragment CH in the H and
13C NMR spectra; the more downfield position of the
signals for this fragment in pyrazoline 6 as compared to
the minor isomer 7 is due to its placement at the nitrogen
atom of the heterocycle (see Experimental). Similarly, the
signal for the proton at the atom C(4) in pyrazoles 8a,b
was found at  ~7.0, while the proton at the atom C(5) in
isomer 9 resonated at  7.95.
As it is known, fluoroꢀ and trifluoromethylꢀcontaining
compounds play an important role in the field of bioꢀ and
agrochemistry. In this connection, we additionally studꢀ
ied several fluorineꢀcontaining unsaturated substrates as
acceptor of nitrilimines, which were generated by therꢀ
molysis of dihydroindazoles 1a,b.
It is known6 that nitrilimines of similar nature generꢀ
ated in situ by 1,3ꢀdehydrochlorination of Nꢀarylchloroꢀ
hydrazones MeO2C—CCl=N—NHAr react with acetylꢀ
enes with the formation of the corresponding pyrazoles.
This process, as a rule, is unselective and gives rise to
a mixture of regioisomeric pyrazolecarboxylates.6,17 We
found that nitrilimines 2a,b generated by thermolysis
of dihydroindazoles 1a,b react similarly. Their cycloaddiꢀ
tion at the triple bond of methyl 4,4,4ꢀtrifluorobutꢀ2ꢀ
ynoate (10) leads to the formation of substituted pyrazoles
11 and 12 in good yields, with 4ꢀ(trifluoromethyl)pyrazoles
11a and 11b being the main regioisomers (Scheme 3). The
isomers were assigned using the 13C NMR spectra based
on the chemical shifts and spinꢀspin coupling constants of
the signals for the atoms C(4) and C(5). In pyrazoles 11a,b,
virtually independent of the substituent on the benzene
ring, the atoms C(4) resonate at  114.2—114.6 as a quarꢀ
The reaction of ethyl bis(trifluoromethyl)acrylate (13)
with nitrilimine 2a proceeded as 1,3ꢀdipolar cycloaddiꢀ
tion, as well, and gives substituted pyrazolines 14 and 15
in 68% total yield, in this case the main isomer is obtained
due to the formation by the nitrilimine of the C—C bond
with the alkene atom bearing the ester group, as a result,
the trifluoromethyl groups ends up to be attached to the
atom C(5) of the heterocycle (Scheme 4).
Besides pyrazolines 14 and 15, pyrazole 12c was found
among the products, whose molecule contained only
one trifluoromethyl group. The formation of the latter
in this process suggested aromatization of pyrazoline 14
with elimination of trifluoromethane. In the 13C and
19F NMR spectra of pyrazole 12c, the signals for the
carbon atoms and the CF3 group are found in the same
regions as analogous signals in the spectra of similar pyrꢀ
azoles 12a,b.
Scheme 4

Reactions of nitrylimines with haloalkenes
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
1141
Scheme 6
In order to study the influence of the fluorine atom on
the reactivity of the double bond, we effected the intercepꢀ
tion of nitrilimines 2a,b with 2ꢀfluoroꢀ3ꢀmethylbutadiene
(16). Like in the case of 1,3ꢀdipolar cycloaddition of diazo
compounds,18 nitrilimines 2a,b can also reacted with difꢀ
ferent double bonds of the diene 16. In this case, the main
pathway of the reaction is the addition of nitrilimines at
the nonfluorinated double bond with the formation of pyrꢀ
azolines 17a,b. The second direction of the reaction, i.e.,
the cycloaddition at the fluorinated double bond, is acꢀ
companied by the elimination of HF and the formation
of pyrazoles 18a,b instead of regioisomeric pyrazolines
(Scheme 5). The structures of the azaheterocycles obtained
were unambiguously inferred from the 1H, 13C, and
19F NMR spectra, as well as from the mass spectrometric
data for the individual compounds isolated by column
chromatography.
X = OMe (a), F (b)
atom of the nitrilimine fragment, unlike in its addition to
the methylated double bonds,16 predominantly attacked
the double bond from the side of the fluorineꢀcontaining
fragment (Scheme 7). Isomeric hexahydroindazoles 23 and
24 were separated by column chromatography, with the
main isomers being additionally recrystallized from CCl4
or a mixture of benzene—ethyl acetate (18 : 1).
Scheme 5
Scheme 7
X = OMe (a), F (b)
Addition of nitrilimines to cyclohexadiene 19 containꢀ
ing an unsubstituted and a difluoroꢀsubstituted double
bond proceeded already exclusively at the nonfluorinated
double bond and mainly led to the expected pyrazolines
20a,b (Scheme 6). When dihydroindazole 1b was used,
the chromatographic fractions, which closely followed the
main fraction, additionally contained a number of minor
compounds, from which we successfully identified isoꢀ
meric pyrazoline 21b. The latter is apparently formed due
to the isomerization of the carbocationic part of the moleꢀ
cule (after the formation of the C—C bond, see Ref. 16)
before it cyclizes to the fiveꢀmembered heterocycle.
The position of the difluoroethene fragment in the sixꢀ
membered ring was found based on the 1H and 13C NMR
spectra and the COSY45 {H,H}ꢀcorrelation.
X = OMe (a), F (b)
1
The regioisomers were assigned based on the H and
13C NMR spectra, taking into account a downfield, as
compared to the HC(3a), position of the signals for the
fragment HC(7a) attached to the nitrogen atom. The
13C NMR spectra of compounds 23a,b because of the
presence of fluorine atoms exhibit a large spinꢀspin couꢀ
pling constant for the signal HC(3a) at  ~50 as compared
to the signal for the fragment HC(7a) found at  64—65.
On the contrary, in the regioisomeric compounds 24a,b,
the downfield signals at  66—67 have the larger spinꢀspin
coupling constant.
Thermolysis of dihydroindazoles 1a,b in the presence
of unsymmetric tetrafluorocyclohexene (22) proceeded
nonselectively and led to the formation of regioisomeric
4,4,5,5ꢀ and 6,6,7,7ꢀtetrafluorohexahydroindazoles 23a,b
and 24a,b in 40—46% total yields. In both cases, the C

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Tomilov et al.
In the case of fluorinated unsaturated compounds 19
and 22, no products of dehydrofluorination or oxidation
of pyrazolines to pyrazoles were found, which was the case
under the same conditions in the formation of some other
pyrazolines.15
tion and identification of the products of conversion of the
remained portion of trichloroethylene were unsuccessful.
Scheme 9
Addition of the nitrilimine fragment during thermolyꢀ
sis of dihydroindazoles 1a,b were detected for vinyl haꢀ
lides, as well. In this case, the corresponding pyrazoles
arisen due to the elimination of hydrogen halide were the
isolated reaction products, rather than pyrazolines. Thus,
thermolysis of dihydroindazole 1a in the presence of
1ꢀbromocyclopentene gave pyrazole 25 in ~30% yield
(Scheme 8), identical to the minor compound obꢀ
tained earlier15 when cyclopentene was used as the interꢀ
ceptor of 2a.
Scheme 8
Finally, the most intriguing result was obtain during
decomposition of dihydroindazole 1a in the presence of
excess 1,1ꢀdichloroꢀ4ꢀmethylpentaꢀ1,3ꢀdiene (28). Reꢀ
peated reproductions of this reaction at 130—140 C gave
rise to the earlier described 1,1,3ꢀtrichloroꢀ4ꢀmethylpentꢀ
1ꢀenꢀ4ꢀol (29)19 and hydrazonoyl chloride 26b as the main
isolated compounds, formed approximately in the equal
molar ratio in 60—65% yields calculated based on 1a
(Scheme 10). Trichloride 29 and hydrazonoyl chloride
26b were also obtained when the reaction was carried out
in oꢀdichlorobenzene at 135 C, however, their yields were
lower, just 45—50%.
It should be noted that when nitrilimine 2a was generꢀ
ated by dehydrochlorination of hydrazonoyl chloride 26b
upon the action of triethylamine in solution of diene 28
and toluene at 110 C, such a process did not occur. Moreꢀ
over, diene 28 were not involved into the reaction at all,
with the cyclic dimer of nitrilimine, dimethyl 1,4ꢀbis(4ꢀ
methoxyphenyl)ꢀ1,2,4,5ꢀtetrazineꢀ3,6ꢀdicarboxylate, beꢀ
ing the main reaction product.7
The results obtained allows us to suggest that in a number
of cases after the heterolytic cleavage of the C(3)—C(3a)
bond in dihydroindazoles 1a,b, not nitrilimine itself can
be involved into the reaction with certain substrates, but
the initially formed bipolar intermediate 30, the negative
charge in which is considerably delocalized over several
ester groups of the sixꢀmembered ring. At the same time,
the cationic center localized on the carbon atom exhibits
properties of a "hard" electrophile. In this case, it can
attack the double bond prior to the cleavage of the C—N
bond (especially in the case of electronꢀenriched olefins)
with the generation of a new carbocationic center, which
after elimination of benzenehexacarboxylic ester either
cyclizes at the nitrogen atom with the formation of pyrꢀ
azolines, or isomerizes with the migration of the proton to
the nitrogen atom,16 or attacks another molecule of the
unsaturated compound, initiating oligomerization processꢀ
es, thereby decreasing the yields of the target compounds.
It is necessary to note that in this reaction, hydraꢀ
zonoyl bromide 26a was virtually absent, whose formation
would have been expected as a result of addition of HBr to
nitrilimine 2a. The low yield of pyrazole 25 can apparently
be explained by the formation of oligomeric products with
participation of molecule 2a and several molecules of the
starting bromocyclopentene.
Nitrilimine 2a also adds to trichloroethylene, howevꢀ
er, this process is even less efficient and gives pyrazole 27
in only ~12% yield. In this case, like in all the preceding
experiments, the starting dihydroindazole was completely
converted and the yield of the benzenehexacarboxylic esꢀ
ter was no lower than 92—95%. Hydrazonoyl chloride 26b
also was isolated from the reaction mixture, whose yield
was twice of that of pyrazole 27 (Scheme 9). Taking into
account that the formation of hydrazonoyl chloride in this
process is not directly related to the addition of HCl to
nitrilimine 2a, it can be suggested that it results from
a direct attack by the electrophilic C atom of the nitrilꢀ
iminium fragment at the halogen atoms with the initial
formation of the C—Cl bond. However, attempted isolaꢀ

Reactions of nitrylimines with haloalkenes
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
1143
Scheme 10
E = CO2Me, R = C6H4OMe
In certain cases, for example, in the presence of the gemiꢀ
nal dichloroethene group and sterically hindered double
bonds, the electrophilic carbon atom of the intermediꢀ
ate 30 can directly attack the vinylic chlorine atom, causꢀ
ing cleavage of the C—Cl bond with subsequent formation
of hydrazonoyl chloride. By the way, the traces of water,
amount of which in the reaction mixture can be sufficient
because of its low molecular weight, can be a source of
protons during formation of the N—H bond. The electroꢀ
philic transfer of the chlorine atom to the starting diꢀ
ene 28, that is the unexpected process, which eventually
leads to trichloride 29. Unfortunately, we did not yet sucꢀ
ceed in the detection of compounds including the fragꢀ
ment of the diene 28 dechlorination in this case, either.
In conclusion, thermal decomposition of Nꢀarylꢀsubꢀ
stituted (heptamethoxycarbonyl)ꢀ3a,7aꢀdihydroindazoles
proceeds with elimination of the hexaester of benzeneꢀ
hexacarboxylic acid and is accompanied by the generation
of intermediates responsible in a number of cases for the
1,3ꢀdipolar cycloaddition of the nitrilimine fragment at
the multiple bonds of the halogenꢀcontaining olefins and
acetylenes with the formation of pyrazolines and pyrazoles.
In the case of the low active or sterically hindered double
bonds, the process can acquire a carbocationic character
due to the initial cleavage of the C(3)—C(3a) bond that
leads to the direct electrophilic attack by these intermediꢀ
ate on the halogen atom of the substrate used with subseꢀ
quent chlorination of the second molecule of the subꢀ
strate. Such a process, in particular, can be responsible for
the formation of 1,1,3ꢀtrichloroꢀ4ꢀmethylpentꢀ1ꢀenꢀ4ꢀol
(29) from 1,1ꢀdichloroꢀ4ꢀmethylpentaꢀ1,3ꢀdiene (28) unꢀ
der the thermal decomposition conditions of the electronꢀ
withdrawing 3a,7aꢀdihydroindazoles.
Experimental
1
H, 13C, and 19F NMR spectra were recorded on Bruker
Avance II 300 (300, 75.5, and 282.4 MHz, respectively) and
Bruker AMXꢀ400 (400.1 and 100.6 MHz) spectrometers for soꢀ
lutions in CDCl3 containing 0.05% Me4Si as an internal stanꢀ
dard; chemical shifts for 19F are given relative to CCl3F. Assignꢀ
ment of signals and determination of isomeric composition of
the compounds formed were performed using homoꢀ and heteroꢀ
nuclear 2D correlation spectra COSY, HMBC, and HSQC.
GLCꢀMS spectra were recorded on a Finnigan MAT DSQII
instrument (EI, 70 eV, the temperature of the system source of
ions—ion trap was 200 C), a Trace GC Ultra chromatograph
equipped with a Thermo TRꢀ5ms SQC column (15 m×0.25 mm)
was used. High resolution spectra spectra were recorded on
a Bruker micrOTOF II spectrometer (ESI) in the positive ions
mode (capillary voltage 4500 V). Thinꢀlayer chromatography
was performed on Silica gel 60 plates (Merck) with visualization
in a chamber with iodine vapors. For preparative separation, we
used column chromatography (silica gel 60, 0.040—0.063 mm,
Merck) with the ratio compound : sorbent ~1 : 100. Melting
points were determined on a Nagema PHMKꢀ05 heating stage.
1ꢀ(4ꢀMethoxyphenyl)ꢀ (1a) and 1ꢀ(4ꢀfluorophenyl)ꢀ
3,3a,4,5,6,7,7aꢀhepta(methoxycarbonyl)ꢀ3a,7aꢀdihydroindazole
(1b),20 methyl 4,4,4ꢀtrifluorobutꢀ2ꢀynoate (10),21 ethyl ,ꢀbisꢀ
(trifluoromethyl)acrylate (13),22 2ꢀfluoroꢀ3ꢀmethylbutadiene
(16),18 and 1,2ꢀdifluorocyclohexaꢀ1,4ꢀdiene (19)18 were obꢀ
tained according to the procedures described earlier. All the

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Tomilov et al.
unsaturated compounds were distilled under inert atmosphere
before use, solvents (>99.5%, chemically pure grade) were used
without additional purification.
(CH2Cl); 52.0 (CO2Me); 55.4 (OMe); 110.3 (C(4)); 114.3 (Cm);
126.8 (Co); 131.0 (Ci); 140.5 (C(5)); 143.4 (C(3)); 160.1 (Cp);
162.3 (COO). Compound 9, colorless crystals, m.p. 72—73 C
(CHCl3—CCl4 (1 : 3)). HRMS (ESI), found: 281.0691 [M + H]+,
369.0503 [M + Na]+. C13H1335ClN2O3. Calculated: 281.0687
[M + H]+, 303.0507 [M + Na]+. MS (EI), m/z (Irel (%) for
35Cl): 280 [M]+ (63), 245 [M – Cl]+ (100), 185 (60), 171 (42).
1H NMR (CDCl3), : 3.85 (s, 3 H, OMe); 3.97 (s, 3 H, CO2Me);
4.89 (s, 2 H, CH2Cl); 6.97, 7.61 (both m, 2 H each, C6H4); 7.95
(s, 1 H, H(5)). 13C NMR (CDCl3), : 36.3 (CH2Cl); 52.2
(CO2Me); 55.7 (OMe); 114.7 (Cm); 121.8 (Co); 123.7 (C(4));
129.2 (C(5)); 133.0 (Ci); 140.6 (C(3)); 159.4 (Cp); 162.7 (COO).
Dimethyl 1ꢀ(4ꢀmethoxyphenyl)ꢀ4ꢀ(trifluoromethyl)ꢀ1Hꢀpyrꢀ
azoleꢀ3,5ꢀdicarboxylate (11a) and dimethyl 1ꢀ(4ꢀmethoxyphenyl)ꢀ
5ꢀ(trifluoromethyl)ꢀ1Hꢀpyrazoleꢀ3,4ꢀdicarboxylate (12a). Pyrꢀ
azole 11a (109 mg, 76%) and regioisomer 12a (20 mg, 14%)
were obtained from compound 1a (255 mg) and methyl 4,4,4ꢀtriꢀ
fluorobutꢀ2ꢀynate (10) (530 mg). Compound 11a, dense oil reꢀ
luctant to crystallize. Found (%): C, 50.16; H, 3.71; N, 7.70.
C15H13F3N2O5. Calculated (%): C, 50.29; H, 3.66; N, 7.82. MS
(EI), m/z (Irel (%)): 358 [M]+ (25), 327 [M – OMe]+ (10), 312
Thermolysis of 3a,7aꢀdihydroindazoles 1a,b in the presence of
halogenꢀcontaining unsaturated compounds (general procedure).
A mixture of heptamethyl dihydroindazoleheptacarboxylate 1a
or 1b (0.4 mmol), an unsaturated compound (3—4 mmol), and
1,4ꢀdioxane (3—3.5 mL) was heated at 135—140 C for 8—9 h in
a sealed tube under Ar. The reaction mixture was analyzed using
1
TLC and H NMR spectroscopy. The main reaction products
were isolated by column chromatography on SiO2, using a mixꢀ
ture of benzene—EtOAc with the gradient of the solvents from
10 : 1 to 2 : 1 as an eluent. In all the cases, benzenehexacarboxyꢀ
lic ester was eluted after the corresponding reaction products.
Methyl 5ꢀ(bromomethyl)ꢀ1ꢀ(4ꢀmethoxyphenyl)ꢀ4,5ꢀdihydroꢀ
1Hꢀpyrazoleꢀ3ꢀcarboxylate (6), methyl 4ꢀ(bromomethyl)ꢀ1ꢀ(4ꢀ
methoxyphenyl)ꢀ4,5ꢀdihydroꢀ1Hꢀpyrazoleꢀ3ꢀcarboxylate (7), and
methyl 5ꢀ(bromomethyl)ꢀ1ꢀ(4ꢀmethoxyphenyl)ꢀ1Hꢀpyrazoleꢀ3ꢀ
carboxylate (8b). Compound 6b (72 mg, 55%), compound 7
(7.9 mg, 6%), and compound 8b (7.8 mg, 6%) were obtained
from compound 1a (252 mg) and allyl bromide (480 mg). Comꢀ
pound 6, yellow crystals, m.p. 88—89 C. Found (%): C, 47.53;
H, 4.74; N, 8.73. C13H15BrN2O3. Calculated (%): C, 47.72;
1
(9), 77 (100). H NMR (CDCl3), : 3.83 (s, 3 H, OMe); 3.85,
3.98 (both s, 3 H each, 2 CO2Me); 6.97, 7.39 (both m, 2 H each,
C6H4). 13C NMR (CDCl3), : 52.8, 53.7 (2 CO2Me); 55.6
(OMe); 114.2 (q, C(4), 2JC,F = 40 Hz); 114.5 (Cm); 120.9 (q, CF3,
1
H, 4.62; N, 8.56. H NMR (CDCl3), : 3.20 (dd, 1 H, Ha(4),
2J = 18.0 Hz, 3J = 6.0 Hz); 3.31 (dd, 1 H, Ha(CHBr), 2J = 10.5 Hz,
3J = 8.7 Hz); 3.37 (dd, 1 H, Hb(4), 2J = 18.0 Hz, 3J = 11.5 Hz);
3.53 (dd, 1 H, Hb(CHBr), 2J = 10.5 Hz, 3J = 2.8 Hz); 3.78 (s, 3 H,
OMe); 3.87 (s, 3 H, CO2Me); 4.80 (m, 1 H, H(5)); 6.87, 7.13
(both m, 2 H each, C6H4). 13C NMR (CDCl3), : 32.1 (CH2Br);
37.0 (C(4)); 52.2 (CO2Me); 55.6 (OMe); 62.2 (C(5)); 114.8 (Cm);
116.8 (Co); 135.3 (Ci); 137.6 (C(3)); 155.4 (Cp); 163.0 (COO).
Compound 7. HRMS (ESI), found: 326.0262 [M]+.
C13H1579BrN2O3. Calculated: 326.0261. 1H NMR (CDCl3),
: 3.57 (dd, 1 H, Ha(CHBr), 2J = 10.3 Hz, 3J = 8.2 Hz); 3.78 (dd,
1 H, Hb(CHBr), 2J = 10.3 Hz, 3J = 3.0 Hz); 3.79 (s, 3 H, OMe);
3.88 (s, 3 H, CO2Me); 3.96 (m, 1 H, H(4)); 4.05 (dd, 1 H, Ha(5),
2J = 11.0 Hz, 3J = 6.9 Hz); 4.15 (dd, 1 H, Hb(5), 2J = 11.0 Hz,
3J = 12.4 Hz); 6.89, 7.13 (both m, 2 H each, C6H4). 13C NMR
(CDCl3), : 33.5 (CH2Br); 45.9 (C(4)); 52.2 (CO2Me); 55.2
(C(5)); 55.7 (OMe); 114.7 (Cm); 115.5 (Co); 136.5 (Ci); 145.8
(C(3)); 155.3 (Cp); 162.9 (COO). Compound 8b. HRMS (ESI),
found: 346.9998 [M + Na]+. C13H1379BrN2O3. Calculated:
347.0002 [M + Na]+. MS (EI), m/z (Irel (%) for 79Br): 324 [M]+
(50), 286 (24), 260 (43), 245 (100), 213 (88). 1H NMR (CDCl3),
: 3.87 (s, 3 H, OMe); 3.95 (s, 3 H, CO2Me); 4.40 (s, 2 H,
CH2Br); 7.00, 7.49 (both m, 2 H each, C6H4); 7.05 (s, 1 H,
H(4)). 13C NMR (CDCl3), : 20.1 (CH2Br); 52.2 (CO2Me);
55.7 (OMe); 110.6 (C(4)); 114.6 (Cm); 127.3 (Co); 131.2 (Ci);
140.9 (C(5)); 143.7 (C(3)); 160.4 (Cp); 162.5 (COO).
1JC,F = 270 Hz); 126.2 (Co); 131.1 (Ci); 136.3 (q, C(5), 3JC,F
=
= 3.0 Hz); 140.8 (q, C(3), 3JC,F = 2.0 Hz); 159.5, 160.4 (2 COO);
160.7 (Cp). 19F NMR (CDCl3), : –57.0. Compound 12a, colorꢀ
less crystals, m.p. 72—73 C (CHCl3—CCl4 (1 : 2)). MS (EI),
m/z (Irel (%)): 358 [M]+ (55), 327 [M – OMe]+ (36), 59 (100).
1H NMR (CDCl3), : 3.87 (s, 3 H, OMe); 3.95, 3.97 (both s,
3 H each, 2 CO2Me); 6.98, 7.38 (both m, 2 H each, C6H4).
13C NMR (CDCl3), : 52.9, 53.4 (2 CO2Me); 55.7 (OMe); 114.4
1
3
(Cm); 118.7 (q, CF3, JC,F = 272 Hz); 119.1 (q, C(4), JC,F
=
= 2.0 Hz); 127.5 (Co); 130.8 (Ci); 131.2 (q, C(5), 2JC,F = 40 Hz);
141.0 (q, C(3), JC,F = 2.0 Hz); 160.7, 162.3 (2 COO); 161.0
(Cp). 19F NMR (CDCl3), : –58.0.
4
Dimethyl 1ꢀ(4ꢀfluorophenyl)ꢀ4ꢀ(trifluoromethyl)ꢀ1Hꢀpyrꢀ
azoleꢀ3,5ꢀdicarboxylate (11b) and dimethyl 1ꢀ(4ꢀfluorophenyl)ꢀ
5ꢀ(trifluoromethyl)ꢀ1Hꢀpyrazoleꢀ3,4ꢀdicarboxylate (12b). Comꢀ
pound 11b (80 mg, 58%) and compound 12b (22 mg, 16%) were
obtained from compound 1b (248 mg) and 4,4,4ꢀtrifluorobutyne
10 (530 mg). Compound 11b, colorless crystals, m.p. 75—76 C
(benzene—AcOEt (20 : 1)). HRMS (ESI), found: 347.0653
[M + H]+, 369.0471 [M + Na]+. C14H10F4N2O4. Calculated:
347.0649 [M + H]+, 369.0469 [M + Na]+. MS (EI), m/z
(Irel (%)): 346 [M]+ (24), 315 [M – OMe]+ (27), 281(15), 229
(14), 95 (100). 1H NMR (CDCl3), : 3.86, 3.99 (both s, 3 H each,
2 CO2Me); 7.19, 7.49 (both m, 2 H each, C6H4). 13C NMR
(CDCl3), : 52.9, 53.8 (2 CO2Me); 114.6 (q, C(4), 2JC,F = 40 Hz);
Methyl 5ꢀ(chloromethyl)ꢀ1ꢀ(4ꢀmethoxyphenyl)ꢀ1Hꢀpyrazoleꢀ
3ꢀcarboxylate (8a) and methyl 4ꢀ(chloromethyl)ꢀ1ꢀ(4ꢀmethoxyꢀ
phenyl)ꢀ1Hꢀpyrazoleꢀ3ꢀcarboxylate (9). Pyrazole 8a (70 mg,
62%) and regioisomer 9 (9 mg, 8%) were obtained from comꢀ
pound 1a (253 mg) and 3ꢀchloropropꢀ1ꢀyne (300 mg). Comꢀ
pound 8a, colorless crystals, m.p. 99—100 C (CHCl3—CCl4
(1 : 3)). Found (%): C, 55.70; H, 4.75; N, 9.91. C13H13ClN2O3.
Calculated (%): C, 55.62; H, 4.67; N, 9.98. MS (EI), m/z (Irel (%)
for 35Cl): 280 [M]+ (100), 249 [M – OMe]+ (23), 245 [M – Cl]+
2
1
116.5 (d, Cm, JC,F = 23 Hz); 120.8 (q, CF3, JC,F = 268 Hz);
127.0 (d, Co, 3JC,F = 9.1 Hz); 134.2 (q, Ci, 4JC,F = 3.3 Hz); 136.3
(q, C(5), 3JC,F = 2.0 Hz); 141.2 (q, C(3), 3JC,F < 2.0 Hz); 159.3,
160.3 (2 COO); 163.2 (d, Cp, JC,F = 251 Hz). 19F NMR
1
(CDCl3), : –57.0 (CF3); –110.5 (CF). Compound 12b. HRMS
(ESI), found: 347.0651 [M + H]+, 369.0467 [M + Na]+.
C14H10F4N2O4. Calculated: 347.0649 [M + H]+, 369.0469
[M + Na]+. MS (EI), m/z (Irel (%)): 346 [M]+ (50), 315
[M – OMe]+ (100), 187(15), 159 (18), 59 (94). 1H NMR
(CDCl3), : 3.96, 3.98 (both s, 3 H each, 2 CO2Me); 7.21, 7.47
(both m, 2 H each, C6H4). 13C NMR (CDCl3), : 52.8, 53.3
1
(70), 213 (46). H NMR (CDCl3), : 3.78 (s, 3 H, OMe); 3.88
(s, 3 H, CO2Me); 4.46 (s, 2 H, CH2Cl); 6.95, 7.40 (both m,
2 H each, C6H4); 6.97 (s, 1 H, H(4)). 13C NMR (CDCl3), : 34.3

Reactions of nitrylimines with haloalkenes
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
1145
1
(2 CO2Me); 118.6 (q, CF3, JC,F = 271 Hz); 116.5 (d, Cm,
C6H4). 13C NMR (CDCl3), : 21.4 (d, Me, 3JC,F = 3.3 Hz); 44.7
2JC,F = 23 Hz); 119.4 (q, C(4), JC,F = 1.7 Hz); 128.2 (d, Co,
(C(4)); 52.1 (CO2Me); 55.8 (OMe); 70.7 (d, C(5), JC,F
=
3
2
3JC,F = 9.3 Hz); 132.2 (q, C(5), JC,F = 40 Hz); 134.1 (q, Ci,
= 25.7 Hz); 92.7 (d, =CH2, 2JC,F = 19.6 Hz); 114.1 (Cm); 121.2
(Co); 135.3 (Ci); 136.6 (C(3)); 156.5 (Cp); 163.1 COO); 165.0
(d, =CF, 1JC,F = 260 Hz). 19F NMR (CDCl3), : –106.5 (br.dd,
2
4JC,F = 3.2 Hz); 141.6 (q, C(3), JC,F < 2.0 Hz); 160.5, 161.9
3
(2 COO); 163.6 (d, Cp, 1JC,F = 252 Hz). 19F NMR (CDCl3), :
–58.0 (CF3); –109.7 (CF).
3
3JH,F = 17.1 Hz, JH,F = 49.0 Hz). Compound 18a, colorless
Methyl 4ꢀethoxycarbonylꢀ1ꢀ(4ꢀmethoxyphenyl)ꢀ5,5ꢀbis(triꢀ
fluoromethyl)ꢀ4,5ꢀdihydroꢀ1Hꢀpyrazoleꢀ3ꢀcarboxylate (14), meꢀ
thyl 5ꢀethoxycarbonylꢀ1ꢀ(4ꢀmethoxyphenyl)ꢀ4,4ꢀbis(trifluoroꢀ
methyl)ꢀ4,5ꢀdihydroꢀ1Hꢀpyrazoleꢀ3ꢀcarboxylate (15), and methyl
4ꢀethoxycarbonylꢀ1ꢀ(4ꢀmethoxyphenyl)ꢀ5ꢀ(trifluoromethyl)ꢀ1Hꢀ
pyrazoleꢀ3ꢀcarboxylate (12c). Pyrazoline 14 (94 mg, 53%), pyrꢀ
azoline 15 (14 mg, 8%), and pyrazole 12c (10 mg, 7%) were
obtained from compound 1a (252 mg) and ethyl bis(trifluoroꢀ
methyl)acrylate (13) (710 mg). Compound 14, colorless dense
oil. Found (%): C, 46.03; H, 3.72; N, 6.57. C17H16F6N2O5.
Calculated (%): C, 46.16; H, 3.65; N, 6.33. MS (EI), m/z
(Irel (%)): 442 [M]+ (75), 369 (19), 337 (18), 300 (17), 269 (100).
1H NMR (CDCl3), : 1.31 (t, 3 H, Me, 3J = 7.0 Hz); 3.82 (s, 3 H,
OMe); 3.87 (s, 3 H, CO2Me); 4.30 (q, 2 H, OCH2, 3J = 7.0 Hz);
4.70 (s, 1 H, H(4)); 6.88, 7.28 (both m, 2 H each, C6H4). 13C NMR
(CDCl3), : 13.8 (Me); 52.8 (CO2Me); 55.5 (OMe); 56.3 (C(4));
crystals, m.p. 118—119 C (CCl4). HRMS (ESI), found: 295.1058
[M + Na]+. C15H16N2O3. Calculated: 295.1053 [M + Na]+. MS
(EI), m/z (Irel (%)): 272 [M]+ (73), 257 [M – Me]+ (48), 241
[M – OMe]+ (25), 239 (25), 225 (100), 209 (20), 197 (17). 1H NMR
(CDCl3), : 1.86 (dd, 3 H, Me, J = 0.9 Hz, J = 1.5 Hz); 3.85
(s, 3 H, OMe); 3.94 (s, 3 H, CO2Me); 5.00 (dq, 1 H, =CHa,
2J = 1.3 Hz, 4J = 0.9 Hz); 5.16 (dq, 1 H, =CHb, 2J = 1.3 Hz, 4J =
= 1.5 Hz); 6.88 (s, 1 H, H(4)); 6.91, 7.38 (both m, 2 H each,
C6H4). 13C NMR (CDCl3), : 22.4 (Me); 52.1 (CO2Me); 55.6
(OMe); 108.9 (C(4)); 114.3 (Cm); 118.9 (=CH2); 126.9 (Co);
133.3 (=C); 133.4 (Ci); 143.2 (C(3)); 145.9 (C(5)); 159.8 (Cp);
163.0 (COO).
4
4
Methyl 1ꢀ(4ꢀfluorophenyl)ꢀ5ꢀ(1ꢀfluorovinyl)ꢀ5ꢀmethylꢀ4,5ꢀ
dihydroꢀ1Hꢀpyrazoleꢀ3ꢀcarboxylate (17b) and methyl 1ꢀ(4ꢀfluoroꢀ
phenyl)ꢀ5ꢀ(propꢀ1ꢀenꢀ2ꢀyl)ꢀ1Hꢀpyrazoleꢀ3ꢀcarboxylate (18b).
Pyrazoline 17b (73 mg, 65%) and pyrazole 18b (9 mg, 8%) were
obtained from compound 1b (250 mg) and fluorobutadiene 16
(340 mg). Compound 17b, pink crystals, m.p. 84—85 C (CCl4).
HRMS (ESI), found: 303.0914 [M + Na]+. C14H14F2N2O2. Calꢀ
culated: 303.0916 [M + Na]+. MS (EI), m/z (Irel (%)): 280 [M]+
(56), 265 [M – Me]+ (7), 249 [M – OMe]+ (6), 233 (37), 111
2
63.0 (OCH2); 78.9 (septet, C(5), JC,F = 29 Hz); 114.1 (Cm);
1
121.2, 122.3 (both q, 2 CF3, JC,F = 288 Hz); 129.3 (Co); 132.8
(Ci); 136.4 (C(3)); 159.8 (Cp); 161.0, 164.5 (2 COO). 19F NMR
(CDCl3), : –66.0, –73.2 (2 CF3, 4JF,F = 9.8 Hz). Compound 15,
colorless dense oil. MS (EI), m/z (Irel (%)): 442 [M]+ (100), 369
(86), 337(17), 300 (68), 269 (90). 1H NMR (CDCl3), : 1.16 (t, 3 H,
Me, 3J = 7.0 Hz); 3.80 (s, 3 H, OMe); 3.90 (s, 3 H, CO2Me);
4.18 (q, 2 H, OCH2, 3J = 7.0 Hz); 5.28 (s, 1 H, H(5)); 6.89, 7.15
(both m, 2 H each, C6H4). 13C NMR (CDCl3), : 14.2 (Me);
52.7 (CO2Me); 55.5 (OMe); 63.3 (OCH2); 66.8 (septet, C(4),
2JC,F = 29 Hz); 69.6 (C(5)); 114.9 (Cm); 117.5 (Co); 121.4, 122.8
(both q, 2 CF3, 1JC,F = 289 Hz); 133.7 (Ci); 140.8 (C(3)); 156.9
(Cp); 160.9, 163.9 (2 COO). 19F NMR (CDCl3), : –61.9, –72.0
1
(25), 110 (31), 109 (100), 95 (65). H NMR (CDCl3), : 1.45
(s, 3 H, Me); 3.09 (dd, 1 H, Ha(4), 2J = 17.6 Hz, 4JH,F = 1.0 Hz);
3.50 (br.d, 1 H, Hb(4), 2J = 17.6 Hz); 3.88 (s, 3 H, CO2Me); 4.69
2
3
(dd, 1 H, =CHa, J = 3.7 Hz, JH,F = 48.0 Hz); 4.89 (dd, 1 H,
2
3
=CHb, J = 3.7 Hz, JH,F = 17.0 Hz); 6.96 (m, 2 H, Hm); 7.28
(m, 2 H, Ho). 13C NMR (CDCl3), : 21.3 (d, Me, 3JC,F = 3.3 Hz);
45.0 (C(4)); 52.2 (CO2Me); 70.4 (d, C(5), 2JC,F = 25.7 Hz); 92.8
(d, =CH2, JC,F = 19.6 Hz); 115.6 (d, Cm, JC,F = 22.7 Hz);
120.2 (d, Co, 3JC,F = 8.0 Hz); 137.6 (C(3)); 138.1 (d, Ci, 4JC,F
= 2.8 Hz); 159.3 (d, Cp, JC,F = 245 Hz); 162.9 (COO); 164.7
(d, =CF, 1JC,F = 261 Hz). 19F NMR (CDCl3), : –106.7 (br.dd,
=CF, JH,F = 17.0 Hz, JH,F = 48.2 Hz); –120.5 (tt, FCp,
3JH,F = 8.4 Hz, 4JH,F = 5.0 Hz). Compound 18b, colorless crysꢀ
tals, m.p. 71—72 C (CCl4). HRMS (ESI), found: 283.0858
[M + Na]+. C14H13FN2O2. Calculated: 283.0853 [M + Na]+.
MS (EI), m/z (Irel (%)): 260 [M]+ (50), 229 [M – OMe]+ (28),
228 (27), 227 (40), 213 (100), 200 (24), 95 (54). 1H NMR
2
2
4
(2 CF3, JF,F = 9.5 Hz). Compound 12c. HRMS (ESI), found:
=
373.3654 [M + H]+. C16H15F3N2O5. Calculated: 373.3649
[M + H]+. MS (EI), m/z (Irel (%)): 372 [M]+ (100), 344 (20),
327 (81), 313 (16). 1H NMR (CDCl3), : 1.39 (t, 3 H, Me,
3J = 7.0 Hz); 3.88 (s, 3 H, OMe); 3.94 (s, 3 H, CO2Me); 4.44 (q,
2 H, OCH2, 3J = 7.0 Hz); 6.97, 7.38 (both m, 2 H each, C6H4).
13C NMR (CDCl3), : 14.0 (Me); 52.8 (CO2Me); 55.7 (OMe);
62.6 (OCH2); 114.4 (Cm); 118.6 (q, CF3, 1JC,F = 270 Hz); 119.5
(q, C(4), 3JC,F = 2.0 Hz); 127.5 (Co); 130.9 (Ci); 132.0 (q, C(5),
1
3
3
4
4
4
2JC,F = 40 Hz); 141.1 (q, C(3), JC,F = 1.5 Hz); 160.7, 161.7
(CDCl3), : 1.88 (dd, 3 H, Me, J = 0.9 Hz, J = 1.5 Hz); 3.94
(2 COO); 161.1 (Cp). 19F NMR (CDCl3), : –58.0.
(s, 3 H, CO2Me); 5.00 (dq, 1 H, =CHa, 2J = 1.3 Hz, 4J = 0.9 Hz);
2
Methyl 5ꢀ(1ꢀfluorovinyl)ꢀ1ꢀ(4ꢀmethoxyphenyl)ꢀ5ꢀmethylꢀ
4,5ꢀdihydroꢀ1Hꢀpyrazoleꢀ3ꢀcarboxylate (17a) and methyl 1ꢀ(4ꢀ
methoxyphenyl)ꢀ5ꢀ(propꢀ1ꢀenꢀ2ꢀyl)ꢀ1Hꢀpyrazoleꢀ3ꢀcarboxylate
(18a). Pyrazoline 17a (61 mg, 52%) and pyrazole 18a (13 mg,
12%) were obtained from compound 1a (253 mg) and 2ꢀfluoroꢀ
3ꢀmethylbutaꢀ1,3ꢀdiene (16) (340 mg). Compound 17a, dense
oil reluctant to crystallize. HRMS (ESI), found: 315.1119
[M + Na]+. C15H17FN2O3. Calculated: 315.1115 [M + Na]+.
MS (EI), m/z (Irel (%)): 292 [M]+ (72), 277 [M – Me]+ (9), 261
[M – OMe]+ (9), 245 (22), 215 (18), 122 (80), 121 (100).
5.19 (dq, 1 H, =CHb, J = 1.3 Hz, 4J = 1.5 Hz); 6.88 (s, 1 H,
H(4)); 7.13 (m, 2 H, Hm); 7.46 (m, 2 H, Ho). 13C NMR (CDCl3),
: 22.4 (Me); 52.2 (CO2Me); 109.2 (C(4)); 116.2 (d, Cm, 2JC,F
=
3
= 23.2 Hz); 119.4 (=CH2); 127.4 (d, Co, JC,F = 8.8 Hz); 133.1
(=C); 136.5 (d, Ci, 4JC,F = 2.9 Hz); 143.7 (C(3)); 146.0 (C(5));
162.5 (d, Cp, 1JC,F = 247 Hz); 162.8 (COO). 19F NMR (CDCl3),
: –112.9 (tt, FCp, 3JH,F = 8.3 Hz, 4JH,F = 4.8 Hz).
Methyl 5,6ꢀdifluoroꢀ1ꢀ(4ꢀmethoxyphenyl)ꢀ3a,4,7,7aꢀtetraꢀ
hydroꢀ1Hꢀindazoleꢀ3ꢀcarboxylate (20a). Compound 20a (86 mg,
67%) was obtained from compound 1a (255 mg) and 1,2ꢀdifluoroꢀ
cyclohexaꢀ1,4ꢀdiene (19) (465 mg), colorless crystals, m.p.
96—97 C (benzene—AcOEt (18 : 1)). Found (%): C, 59.43;
H, 5.07; N, 8.47. C16H16F2N2O3. Calculated (%): C, 59.62;
H, 5.00; N, 8.69. MS (EI), m/z (Irel (%)): 322 [M]+ (30), 291
[M – OMe]+ (6), 232 (100), 217 (12), 201 (30), 90 (50). 1H NMR
4
1H NMR (CDCl3), : 1.42 (d, 3 H, Me, JH,F = 1.1 Hz); 3.06
(br.d, 1 H, Ha(4), 2J = 17.5 Hz); 3.49 (br.d, 1 H, Hb(4), 2J =
= 17.5 Hz); 3.78 (s, 3 H, OMe); 3.86 (s, 3 H, CO2Me); 4.64 (dd,
1 H, =CHa, 2J = 3.6 Hz, 3JH,F = 49.0 Hz); 4.86 (dd, 1 H, =CHb,
3
2J = 3.6 Hz, JH,F = 17.1 Hz); 6.97, 7.38 (both m, 2 H each,

1146
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
Tomilov et al.
1
(CDCl3), : 2.46, 2.68 (both m, 1 H each, H2C(4)); 2.77, 2.95
(both m, 1 H each, H2C(7)); 3.79 (s, 3 H, OMe); 3.80 (m, 1 H,
HC(3a)); 3.87 (s, 3 H, CO2Me); 4.65 (m, 1 H, HC(7a)); 6.88,
7.14 (both m, 2 H each, C6H4). 13C NMR (CDCl3), : 24.7
(d, C(4), 2JC,F = 21.5 Hz); 26.4 (d, C(7), 2JC,F = 21.1 Hz); 42.6
51 (14). H NMR (CDCl3), : 2.20—2.35 (m, 2 H, H2C(5));
2.37—2.48 (m, 2 H, CH2(6)); 5.80 (dtt, 1 H, H(1), J1,2 = 10.0 Hz,
J = 3.0 Hz, J = 5.0 Hz); 6.25 (dd, 1 H, H(2), J1,2 = 10.0 Hz,
J = 3.5 Hz). 13C NMR (CDCl3), : 23.6 (tt, C(6), 4JC,F = 5.2 Hz,
3JC,F = 2.0 Hz); 28.4 (tt, C(5), 2JC,F = 23.0 Hz, 3JC,F = 1.0 Hz);
112.7 (tt, C(4), 1JC,F = 273 Hz, 2JC,F = 23.0 Hz); 117.0 (tt, C(3),
1JC,F = 278 Hz, 2JC,F = 25.0 Hz); 121.5 (tt, C(1), 3JC,F = 27.0 Hz,
4JC,F = 0.7 Hz); 137.6 (tt, C(2), 2JC,F = 10.5 Hz, 3JC,F = 1.0 Hz).
19F NMR (CDCl3), : –111.9 (2 F, F2C(3)); –121.7 (2 F, F2C(4)).
3
(d, C(3a), JC,F = 7.6 Hz); 52.2 (CO2Me); 55.6 (OMe); 61.4
3
(d, C(7a), JC,F = 7.2 Hz); 114.7 (Cm); 118.6 (Co); 135.5 (Ci);
1
2
138.1 (dd, C(6), JC,F = 253 Hz, JC,F = 10.5 Hz); 139.9 (dd,
C(5), 1JC,F = 255 Hz, 2JC,F = 10.1 Hz); 140.8 (C(3)); 156.1 (Cp);
162.9 (COO). 19F NMR (CDCl3), : –136.8, –137.5 (both m,
FC=CF).
Methyl
4,4,5,5ꢀtetrafluoroꢀ1ꢀ(4ꢀmethoxyphenyl)ꢀ
3a,4,5,6,7,7aꢀhexahydroꢀ1Hꢀindazoleꢀ3ꢀcarboxylate (23a) and
methyl 6,6,7,7ꢀtetrafluoroꢀ1ꢀ(4ꢀmethoxyphenyl)ꢀ3a,4,5,6,7,7aꢀ
hexahydroꢀ1Hꢀindazoleꢀ3ꢀcarboxylate (24a). Compound 23a
(43 mg, 30%) and compound 24a (14.5 mg, 10%) were obtained
from compound 1a (254 mg) and 3,3,4,4ꢀtetrafluorocycloꢀ
hexene (22) (610 mg). Compound 23a, yellowish crystals, m.p.
134—135 C (CCl4). Found (%): C, 53.18; H, 4.51; N, 7.57.
C16H16F4N2O3. Calculated (%): C, 53.34; H, 4.48; N, 7.78. MS
(EI), m/z (Irel (%)): 360 [M]+ (100), 345 [M – Me]+ (30), 329
[M – OMe]+ (25), 301 (50), 291 (10), 281 (80), 266 (50), 147
(25), 134 (30), 121 (75). 1H NMR (CDCl3), : 2.05—2.45
(m, 4 H, CH2CH2); 3.75 (s, 3 H, OMe); 3.85 (s, 3 H, CO2Me);
3.90 (m, 1 H, H(3a)); 4.29 (m, 1 H, H(7a)); 6.85, 7.10 (both m,
2 H each, C6H4). 13C NMR (CDCl3), : 19.7 (dd, C(7), 3JC,F
= 7.9 Hz, JC,F = 2.9 Hz); 26.5 (dt, C(6), JC,F = 22.2 Hz,
3JC,F = 2.5 Hz); 49.6 (dt, C(3a), 2JC,F = 20.2 Hz, 3JC,F = 2.0 Hz);
52.5 (CO2Me); 55.6 (OMe); 64.8 (dd, C(7a), JC,F = 8.3 Hz,
3JC,F = 1.4 Hz); 113.6, 116.2 (both m, CF2CF2); 114.6 (Cm);
122.7 (Co); 135.5 (Ci); 136.1 (d, C(3), JC,F = 3.3 Hz); 157.8
Methyl 5,6ꢀdifluoroꢀ1ꢀ(4ꢀfluorophenyl)ꢀ3a,4,7,7aꢀtetrahyꢀ
droꢀ1Hꢀindazoleꢀ3ꢀcarboxylate (20b) and methyl 6,7ꢀdifluoroꢀ1ꢀ
(4ꢀmethoxyphenyl)ꢀ3a,4,5,7aꢀtetrahydroꢀ1Hꢀindazoleꢀ3ꢀcarboxylꢀ
ate (21b). Compound 20b (56 mg, 45%) and isomer 21b (5 mg,
4%) were obtained from compound 1b (248 mg) and diene 19
(460 mg). Compound 20b, colorless crystals, m.p. 102—104 C
(CCl4). Found (%): C, 57.88; H, 4.30; N, 8.84. C15H13F3N2O2.
Calculated (%): C, 58.07; H, 4.22; N, 9.03. MS (EI), m/z
(Irel (%)): 310 [M]+ (30), 279 [M – OMe]+ (5), 220 (95), 189
1
(100), 162 (31), 109 (30), 95 (84). H NMR (CDCl3), : 2.46,
2.72 (both m, 1 H each, H2C(4)); 2.80, 3.00 (both m, 1 H each,
H2C(7)); 3.84 (m, 1 H, HC(3a)); 3.88 (s, 3 H, CO2Me); 4.70
(m, 1 H, HC(7a)); 7.05, 7.16 (both m, 2 H each, C6H4). 13C NMR
=
2
3
2
(CDCl3), : 24.6 (d, C(4), JC,F = 22.0 Hz); 26.6 (d, C(7),
2JC,F = 21.5 Hz); 43.1 (d, C(3a), 3JC,F = 7.3 Hz); 52.4 (CO2Me);
60.9 (d, C(7a), 3JC,F = 7.0 Hz); 116.2 (d, Cm, 2JC,F = 22.8 Hz);
3
3
1
118.0 (d, Co, JC,F = 8.3 Hz); 138.0 (dd, C(6), JC,F = 256 Hz,
2JC,F = 11.5 Hz); 138.1 (d, Ci, 4JC,F = 2.2 Hz); 139.8 (dd, C(5),
3
1JC,F = 255 Hz, JC,F = 10.4 Hz); 141.5 (C(3)); 159.1 (d, Cp,
(Cp); 162.0 (COO). 19F NMR (CDCl3), : –117.7, –119.5,
–120.3, –122.8 (all m, F2CCF2). Compound 24a, yellowish crysꢀ
tals, m.p. 104—105 C (CCl4). HRMS (ESI), found: 383.0983
[M + Na]+. C16H16F4N2O3. Calculated: 383.0989 [M + Na]+.
MS (EI), m/z (Irel (%)): 360 [M]+ (100), 345 [M – Me]+ (20),
329 [M – OMe]+ (5), 301 (25), 245 (7), 134 (15), 121 (17), 92
(10). 1H NMR (CDCl3), : 2.08—2.31, 2.70 (both m, 3 H + 1 H,
CH2CH2); 3.80 (m, 1 H, H(3a)); 3.73 (s, 3 H, OMe); 3.87 (s, 3 H,
CO2Me); 4.78 (m, 1 H, H(7a)); 6.87, 7.27 (both m, 2 H each,
2
1JC,F = 244 Hz); 162.7 (COO). 19F NMR (CDCl3), : –121.0
(tt, FCp, 3JH,F = 8.4 Hz, 4JH,F = 4.2 Hz); –136.5, –137.1 (both m,
FC=CF). Compound 21b, HRMS (ESI), found 333.0813
[M + Na]+. C15H13F3N2O2. Calculated: 333.0821 [M + Na]+.
GLCꢀMS (EI), m/z (Irel (%)): 310 [M]+ (72), 279 [M – OMe]+
1
(5), 250 (8), 185 (24), 111 (50), 109 (100), 95 (45). H NMR
(CDCl3), : 2.05, 2.34, 2.45, 2.74 (all m, 1 H each, H2C(4),
H2C(5)); 3.79 (m, 1 H, HC(3a)); 3.87 (s, 3 H, CO2Me); 5.00
(m, 1 H, HC(7a)); 7.00, 7.26 (both m, 2 H each, C6H4). 13C NMR
C6H4). 13C NMR (CDCl3), : 18.4 (t, C(4), JC,F = 5.2 Hz);
3
(CDCl3), : 21.1 (d, C(4), 3JC,F = 6.8 Hz); 23.1 (d, C(5), 2JC,F
= 20.1 Hz); 45.1 (dd, C(3a), JC,F = 6.5 Hz, JC,F = 2.0 Hz);
52.3 (CO2Me); 62.5 (dd, C(7a), 2JC,F = 19.1 Hz, 3JC,F = 2.5 Hz);
=
28.4 (t, C(5), 2JC,F = 22.0 Hz); 44.2 (d, C(3a), 3JC,F = 5.8 Hz);
3
4
2
52.3 (CO2Me); 55.6 (OMe); 66.7 (dd, C(7a), JC,F = 19.0 Hz,
2JC,F = 24.4 Hz); 114.4 (Cm); 114.5, 116.4 (both m, CF2CF2);
120.2 (Co); 136.4 (Ci); 139.4 (C(3)); 156.7 (Cp); 162.6 (COO).
19F NMR (CDCl3), : –118.3, –121.8 (both br.d, CF2, JF,F
2
3
115.7 (d, Cm, JC,F = 22.9 Hz); 119.3 (dd, Co, JC,F = 8.1 Hz,
5JC,F = 3.3 Hz); 139.5 (dd, C(7), 1JC,F = 254 Hz, 2JC,F = 11.4 Hz);
2
=
4
139.7 (d, Ci, JC,F = 2.4 Hz); 140.5 (C(3)); 147.9 (dd, C(6),
= 258 Hz); –118.8 (br.s, CF2).
1JC,F = 263 Hz, 2JC,F = 10.4 Hz); 159.4 (d, Cp, 1JC,F = 243 Hz);
Methyl
4,4,5,5ꢀtetrafluoroꢀ1ꢀ(4ꢀfluorophenyl)ꢀ
162.6 (COO). 19F NMR (CDCl3), : –120.7 (tt, FCp, JH,F
=
3a,4,5,6,7,7aꢀhexahydroꢀ1Hꢀindazoleꢀ3ꢀcarboxylate (23b) and
methyl 6,6,7,7ꢀtetrafluoroꢀ1ꢀ(4ꢀfluorophenyl)ꢀ3a,4,5,6,7,7aꢀ
hexahydroꢀ1Hꢀindazoleꢀ3ꢀcarboxylate (24b). Compound 23b
(45 mg, 32%) and isomer 24b (19.5 mg, 14%) were obtained
from compound 1b (248 mg) and 3,3,4,4ꢀtetrafluorocyclohexene
(22) (0.60 g). Compound 23b, colorless crystals, m.p. 110—111 C
(benzene—AcOEt (18 : 1)). Found (%): C, 51.51; H, 3.81;
N, 7.96. C15H13F5N2O2. Calculated (%): C, 51.73; H, 3.76;
N, 8.04. MS (EI), m/z (Irel (%)): 348 [M]+ (73), 317 [M – OMe]+
(22), 289 (38), 269 (100), 249 (16), 235 (26), 215 (15), 189 (16),
148 (15), 135 (18), 122 (26), 109 (45), 95 (75). 1H NMR (CDCl3),
: 2.10—2.40 (m, 4 H, CH2CH2); 3.91 (s, 3 H, CO2Me); 3.97
(m, 1 H, H(3a)); 4.38 (m, 1 H, H(7a)); 7.07, 7.16 (both m,
3
= 8.5 Hz, 4JH,F = 4.3 Hz); –127.5, –145.1 (both m, FC=CF).
3,3,4,4ꢀTetrafluorocyclohexene (22). A flow of gaseous tetraꢀ
fluoroethylene (130 mL min–1) and butadiene (130 mL min–1
)
was passed with a constant speed through a quartz tubular reacꢀ
tor (2×55 cm) heated in a tubular oven to 490—500 C. The
pyrolysis products coming out of the reactor were condensed in
a water condenser and collected in a cooled receiver. After 1 h,
44 g of liquid pyrolyzate was obtained, which was distilled with
water vapor and dried with anhydrous CaCl2. The reaction mixꢀ
ture (~37 g), containing according to the GC data 53% of tetraꢀ
fluorocyclohexene 22, was fractionally distilled on a column at
reduced pressure, collecting the fraction with b.p. 68—70 C
(90 Torr) to obtain compound 22 (16.9 g, 32%) with 98% purity.
MS (EI), m/z (Irel (%)): 154 [M]+ (10), 115 (11), 90 (100), 64 (27),
2 H each, C6H4). 13C NMR (CDCl3), : 19.8 (dd, C(7), 3JC,F
= 7.6 Hz, JC,F = 3.0 Hz); 26.8 (td, C(6), JC,F = 22.5 Hz,
=
3
2

Reactions of nitrylimines with haloalkenes
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
1147
3JC,F = 1.8 Hz); 50.1 (td, C(3a), 2JC,F = 25.0 Hz, 3JC,F = 1.8 Hz);
Scientific Schools of the Russian Federation, Grant
NShꢀ8242.2010.3).
3
52.6 (CO2Me); 63.8 (br.d, C(7a), JC,F = 8.4 Hz); 113.6, 116.0
(both m, CF2CF2); 116.3 (d, Cm, 2JC,F = 22.9 Hz); 121.8 (d, Co,
4
3JC,F = 8.1 Hz); 136.8 (d, Ci, JC,F = 3.3 Hz); 138.4 (d, C(3),
References
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3JC,F = 2.5 Hz); 160.5 (d, Cp, JC,F = 273 Hz); 161.6 (COO).
19F NMR (CDCl3), : –117.6, –118.8, –119.6, –121.6 (all m,
F2CCF2, 2JF,F = 252—260 Hz). Compound 24b, HRMS (ESI),
found: 349.0969 [M + Na]+. C15H13F5N2O2. Calculated:
349.0970 [M + Na]+. MS (EI), m/z (Irel (%)): 348 [M]+ (100),
317 [M – OMe]+ (18), 289 (50), 247 (19), 237 (28), 215 (35),
187 (18), 122 (50), 109 (22), 95 (80). 1H NMR (CDCl3), : 2.20,
2.75 (both m, 3 H + 1 H, CH2CH2); 3.85 (m, 1 H, H(3a)); 3.88
(s, 3 H, CO2Me); 4.84 (m, 1 H, H(7a)); 7.03, 7.30 (both m,
1. R. Huisgen, Angew. Chem., Int. Ed. Engl., 1963, 2, 565; 633.
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Chemistry, Ed. A. Padwa, Wiley Interscience, New York,
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2 H each, C6H4). 13C NMR (CDCl3), : 18.2 (dd, C(4), 3JC,F
=
3
2
= 5.5 Hz, JC,F = 5.1 Hz); 28.3 (dt, C(6), JC,F = 21.6 Hz,
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Methyl 1ꢀ(4ꢀmethoxyphenyl)ꢀ1,4,5,6ꢀtetrahydrocyclopentaꢀ
[c]pyrazoleꢀ3ꢀcarboxylate (25). Compound 25 (32.6 mg, 30%)
was obtained from compound 1a (254 mg) and 1ꢀbromocycloꢀ
pentene (588 mg, 4 mmol), which was identical to the sample
obtained earlier.15
Methyl 4,5ꢀdichloroꢀ1ꢀ(4ꢀmethoxyphenyl)ꢀ1Hꢀpyrazoleꢀ3ꢀ
carboxylate (27). Pyrazole 27 (14.5 mg, 12%) and hydrazonoyl
chloride 26b (24 mg, 25%) were isolated from compound 1a
(255 mg) and trichloroethylene (0.46 g, 3.5 mmol) (cf. Ref. 23).
Compound 27, HRMS (ESI), found: 323.1468 [M + Na]+.
C12H1035Cl2N2O3. Calculated: 323.1463 [M + Na]+. MS (EI),
m/z (Irel (%) for 35Cl): 300 [M]+ (100), 269 [M – OMe]+ (19),
206 (40), 191 (24), 171 (27). 1H NMR (CDCl3), : 3.86 (s, 3 H,
OMe); 3.97 (s, 3 H, CO2Me); 6.99, 7.45 (both m, 2 H each,
C6H4). 13C NMR (CDCl3), : 52.4 (CO2Me); 55.7 (OMe); 112.2
(C(4)); 114.4 (Cm); 126.8 (Co); 127.9 (C(5)); 130.7 (Ci); 139.4
(C(3)); 160.5 (Cp); 160.8 (COO).
1,1,3ꢀTrichloroꢀ4ꢀmethylpentꢀ1ꢀenꢀ4ꢀol (29). Trichloride 29
(53 mg, 65% calculated based on dihydroindazole 1a) was obꢀ
tained from compound 1a (253 mg) and 1,1ꢀdichloroꢀ4ꢀmethylꢀ
pentaꢀ1,3ꢀdiene (28) (423 mg, 2.8 mmol). The NMR spectra of 29
were identical to those for the compound synthesized earlier.19
Hydrazonoyl chloride 26b (58 mg, ~60%) (cf. Ref. 23) and benzꢀ
enehexacarboxylic ester (156 mg, ~92%) were isolated, as well.
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The authors are grateful to E. V. Shulishov (N. D.
Zelinsky Institute of Organic Chemistry of the Russian
Academy of Sciences) for the methodical help in recordꢀ
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1
ing 2D H and 13C NMR spectra, as well as 19F NMR
spectra.
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 09ꢀ03ꢀ00636)
and the Council on Grants at the President of the Russian
Federation (Program of State Support for Leading
Received December 19, 2011