Mechanism of formation of 2,1-benzisoxazoles in reactions of nitroarenes with arylacetonitriles

Article abstract of DOI:10.1134/S1070428015020190

Main regularities in reactions of arylacetonitriles with nitroarenes were discussed. The reaction mechanism has been suggested proceeding from the experimental data and the quantum chemical modeling of the limiting stage, the formation of the 2,1-benzisoxazole ring.

Full text of DOI:10.1134/S1070428015020190

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2015, Vol. 51, No. 2, pp. 245–252. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © V.Yu. Orlov, A.D. Kotov, A.V. Tsivov, A.I. Rusakov, 2015, published in Zhurnal Organicheskoi Khimii, 2015, Vol. 51, No. 2,
pp. 255–262.
Mechanism of Formation of 2,1-Benzisoxazoles in Reactions
of Nitroarenes with Arylacetonitriles
V. Yu. Orlov, A. D. Kotov, A. V. Tsivov, and A. I. Rusakov
Demidov Yaroslavl State University, ul. Sovetskaya 14, Yaroslavl, 150000 Russia
e-mail: alex_tsivov@mail.ru
Received August 6, 2014
Abstract—Main regularities in reactions of arylacetonitriles with nitroarenes were discussed. The reaction
mechanism has been suggested proceeding from the experimental data and the quantum chemical modeling of
the limiting stage, the formation of the 2,1-benzisoxazole ring.
DOI: 10.1134/S1070428015020190
The research object of this study is the reaction of
nitroarenes with carbanions of arylacetonitriles that
depending on the structures of the substrate and the
reagent affords different products: from quinone
oximes to heterocycles. The reaction of para-
substituted nitroarenes with arylacetonitriles provide
2,1-benzisoxazoles (anthranils) [1] (Scheme 1, Х ≠ Н).
The reactions of arylacetonitriles with nitroarenes
lacking a substituent in the para-position [2] (Х = Н)
leads to the formation of arylcyanomethylene-para-
quinone monooximes.
However further in the study on the reactions of aryl-
acetonitriles with nitroarenes lacking a substituent in the
para-position we showed experimentally the reversibi-
lity of the formation of arylcyanomethylene-para-quino-
ne monooximes [7], isolated in the individual state and
characterized by the modern physicochemical analy-
tical methods (1Н, IR, and mass spectra) the minor pro-
ducts of the reactions of the para-substituted nitroare-
nes with some arylacetonitriles [8, 9]. All these data
made it possible to suggest the reversibility of some sta-
ges in the reactions of arylacetonitriles with para-substi-
tuted nitroarenes involving analogous intermediates А–С,
excluding the last associative cyclization stage and the for-
mation of the final 2,1-benzisoxazoles 3, and also to revi-
se the problem of the limiting stage of the overall process.
The mentioned reactions proceed in the media of
monohydric aliphatic alcohols in the presence of a
large excess (at least two-fold) of sodium or potassium
hydroxide. At the use of other solvents or of lesser
amounts of alkali metal hydroxide side processes
become prevailing (substitution of halogens and the
other nucleofuges, hydrolysis of the cyano group, etc.).
In [10] also treating the problems of the formation
of 2,1-benzisoxazoles the mechanism of the cycli-
zation was studied in detail with the help of the
quantum chemical modeling. The obtained values of
the energy barriers to the cyclization stage allowed
suggesting a hypothesis that this stage was limiting
and governing the process laws.
In [3, 4] we investigated the effect of the structures
of substrates and reagents on the direction of reactions
of mono- and polysubstituted nitrobenzenes, nitrohete-
rocycles, and also dinitroarenes with arylacetonitriles
and determined the general structural limitations for
substrates and reagents.
Scheme 1.
N
X = H
Proceeding from the analysis of the data on the
study of reactions of para-substituted nitroarenes 1
with arylacetonitriles 2 [5, 6] we concluded that the
limiting stage in the building up of the final 2,1-
benzisoxazoles 3 was the formation of σH-complexes
А (Scheme 2).
NO2
O
CN
X
EtOH
NaOH
Ar
CH2
+
Ar
OH
Ar
X
X = H
C
N
NC
245

ORLOV et al.
246
Scheme 2.
CN
CH2
Ar
H_OR
H_OR
_OR
_O
_
_O O_
N+
H2O OH
_O
OH
N
X
Ar
O
N
NO2
CN
CH
N
X
CN
Ar
CN
CN
CH_
Ar
Ar
_H2O
H2O
C
H
_CN_
+
H
Ar
RO_
_
ROH
X
RO
X
X
1
2
A
B
C
3
However only a single process was considered at
the simulation in [10]: the reaction of 4-nitrochloro-
benzene 1a with phenylacetonitrile 2а giving 3-phe-
nyl-5-chloro-2,1-benzisoxazole 3а. Besides the data on
the nature of the limiting stage obtained as a result of
the simulation had no significant experimental confir-
mation.
presence of a large excess of sodium hydroxide in a
nitrogen flow beside the target 3-(3,4-dimethoxy-
phenyl)-5-chloro-2,1-benzisoxazole 3b, 9-cyano-10-
acridine-N-oxide 4, and 3,4-dimethoxybenzoic acid 5 a
bright red crystalline substance was isolated possessing
a clear narrow melting point and individual state accor-
1
ding to chromatographic data. From the Н, IR, and
mass spectra it was suggested that this compound was
a mixture of stereoisomers of ortho-quinone oxime
corresponding to intermediate C, [6-(hydroxyimino)-3-
chlorocyclohexa-2,4-dien-1-ylidene]-(3,4-dimethoxy-
phenyl)acetonitrile 6 (Scheme 3).
Therefore we report here on a deeper investigation
of the target process including both experimental
studies and the quantum chemical modeling on a wide
range of compounds (with various substituents in the
structure of 4-nitrobenzene).
Thus we have for the first time experimentally es-
tablished the existence of intermediate C (Scheme 2) and
examined its characteristics. This proves that the reaction
type under study proceeds through the corresponding
ortho-quinone monooximes, key intermediate subs-
tances in the formation of the 2,1-benzisoxazole ring.
We also analyzed the correlation dependences
between calculated and experimental reaction para-
meters that permitted verification of the assumption on
the limiting stage of the reaction.
To confirm the existence of the intermediate states
involved in the formation of the ring by the transition
intermediate С → final product 3 we attempted to isolate
and characterize the intermediates of reactions of 4-
nitrochlorobenzene 1а with various arylacetonitriles.
Further aiming to carry out the preliminary
identification of the limiting stage we performed the
quantum chemical modeling of all stages of the
reaction between 4-nitrochlorobenzene 1а and phenyl-
acetonitrile 2а leading finally to the formation of 3-
phenyl-5-chloro-2,1-benzisoxazole 3а.
In the reaction of 4-nitrochlorobenzene 1а with 3,4-
dimethoxyphenylacetonitrile 2b in 2-propanol in the
Scheme 3.
Cl
Cl
CN
Cl
N
O
NO2
CH2
COOH
HO
N
2-PrOH
NaOH
N+ O_
+
+
C
CN
+
+
CN
OCH3
OCH3
Cl
OCH3
OCH3
H3CO
OCH3
OCH3
H3CO
OCH3
OCH3
1a
2b
3b
4
5
6
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 2 2015

MECHANISM OF FORMATION OF 2,1-BENZISOXAZOLES IN REACTIONS
247
–1
H
Δ
кДж/моль
450
f,
450
O
ΔНf, kJ mol
O-
TS
339988..5511
ПС
N
Ph
N
Ph
HO
O
NO2
HO N
O-H
400
400
NO2
Ph
HH
H
N
CN CN
HH
CN
37327.62.161
Ph
350
350
Ph
CN
Ph
CN
CN
В
Cl
Cl
300
300
Cl
Cl
C
Cl
А
A
Cl
ПС
TS
Б
O
250
250
N
B
O
N
212.35
212.35
Ph
ПС
200
200
TS
Ph
155.15
155.15
187.96
187.96
150
150
Cl
IIIа
Cl
3а
100
100
116.06
116.06
73.37
73.37
50
50
0
0
Fig. 1. Energy diagram of the formation of 3-phenyl-5-chloro-2,1-benzisoxazole 3а (calculation by MOPAC/PM7).
The energy characteristics were calculated for the
hypothetical intermediates, the final products, and the
transition states. The energy parameters of the
intermediates and the transition states are presented in
Fig. 1.
The third stage involves the transfer of the second
hydrogen atom to the nitro group with simultaneous
water liberation. This results in the ionic form С of the
reaction product, which in the reaction of
arylacetonitriles with nitroarenes without a substituent
in the para-position to the nitro group leads to the
formation of para-quinone monooximes, and in the
reaction of arylacetonitriles with para-substituted
nitroarenes by the subsequent cyclization gives 2,1-
benzisoxazoles 3 (the fourth stage). According to the
assumed theoretical model this stage may be the key
(limiting) one leading to the formation of the final 2,1-
benzisoxazoles.
The comparison of the obtained energy
characteristics shows that the most difficult stage is the
latter, namely, the cyclization.
Therefore based on the investigation of the
regularities of the target reaction course, on the
analysis and interpretation of experimental and
published data we suggest in this report the following
theoretical model of the studied process (Scheme 2).
Further exploration of the course of the cyclization
stage by the transition of intermediate С into the final
product 3 as the assumed limiting stage of the whole
process (Scheme 4) was carried out using the quantum
chemical calculations together with the analysis of the
obtained experimental data. We performed reactions of 4-
Х-nitrobenzenes 1а–1h with phenylacetonitrile 2а af-
fording 3-phenyl-5-Х-2,1-benzisoxazoles 3а and 3c–3i.
In the first stage the molecule of phenylacetonitrile
2 in the alkaline environment is converted in stable
carbanion and further reacts in this form with
nitrobenzene 1 giving as a result σН-complex А.
The second stage consists in the hydrogen transfer
on the nitro group involving the solvent thus forming
intermediate В.
Scheme 4.
O1
CN
CH2
_
CN
O1
C7
NO2
N
N
C7 Ph
Ph
+
_CN_
X
X
X
1a_1h
C
2a
3a, 3c_3i
X = Cl (1а, 3а), Br (1b, 3c), Ph (1c, 3d), PhO (1d, 3e), CH(OCH2)2 (1e, 3f), MeC(OCH2)2 (1f, 3g), COOH (1g, 3h),
4-MeC(OCH2)2C6H4 (1h, 3i).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 2 2015

ORLOV et al.
corresponding to the source intermediate С, to 1.3 Å
248
(a)
corresponding to the final product 3, with the step of
0.1 Å (Scheme 4). At the distance С7–О1 1.3–1.5 Å the
presumable cleavage of the cyano group C9N2 occurs
with the subsequent formation of the 2,1-
benzisoxazole ring (Fig. 2b).
a
Na1
N2
C9
C7
O1
The structures with the distance 1.9–2.0 Å
correspond to the transition state of the studied
cyclization stage (Fig. 2а). At the rapprochement of the
reaction sites С7–О1 to this distance the cyano group
C9N2 is not yet liberated, and the transition state has
the maximum energy on the course along the PES
profile (Figs. 3, 4).
Cl1
The calculation of Hessians for the found transition
states of all structures showed that for each TS a single
imaginary frequency was present corresponding to the
linear vibration of the system along the С7–О1
direction that confirmed the correctness of the
structure of these TS. Therewith the mentioned С7–О1
direction corresponds to the intrinsic reaction
coordinate where the change results in the transition of
the system “intermediate–final product” from the
initial to the final state.
(b)
б
Na1
N2
C9
O1
C7
The PES profiles for the transition intermediate
С → final product 3 constructed as a function of the
С7–O1 distance and shown in the scale the relative
energies Еrel are presented in Figs. 3, 4. The calculation
was carried out with accounting for the solvation
surrounding (model solvent MeOH).
Cl1
Fig. 2. Geometric configuration of the transition state of
cyclization (а) and of the final reaction product (b) 3а
[calculation by PC GAMESS, UHF/6-31G(d,p)].
The correlation was examined between the
experimentally obtained values of the effective rate
constants keff of the formation of 2,1-benzisoxazoles 3а
and 3с–3e and the calculated values of the energy
parameters of the transition states. The parameters
selected for the correlation (indices of the reactivity)
are the values of the activation barriers in the
presumed limiting stage of the formation of 2,1-
benzisoxazole rings (Table 1).
For accounting for the solvate surrounding we
selected the discrete model compatible with UHF
(Unrestricted Hartree-Fock) approximation that was
realized by the addition of two solvent molecules
(alcohol series: methanol–2-propanol). The prelimi-
nary calculations showed that the increase in the
number of considered solvent molecules did not result
in a significant structural and electronic deformation of
the initial structure. In order to study the reaction with
accounting for the real surrounding the positively
charged counterions Na+ were introduced into the
molecular system (Fig. 2).
A correlation dependence was found of lnkeff on the
values of the activation barriers Еact obtained by
quantum chemical modeling of the cyclization process
(Fig. 5).
For structures 3а and 3c–3i a linear correlation was
observed between the Еact of the formation of 2,1-
benzisoxazole rings obtained by quantum chemical
modeling and the experimentally found values of the
logarithms of the effective rate constants of the
reactions between para-substituted nitrobenzenes and
The simulation of the intramolecular nucleophilic
attack during the formation of the 2,1-benzisoxazole
rings was performed by gradual rapprochement of the
reaction sites, atoms С7 and О1, from the distance 3.0 Å
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 2 2015

MECHANISM OF FORMATION OF 2,1-BENZISOXAZOLES IN REACTIONS
350
249
IIIд
3e
300
250
200
150
100
50
IIIг
3d
IIIв
3c
IIIа
3a
Переходное
Traсnоsiсtтiоoяnнsиtеate
Final product
Конечный
3
продукт (III)
Интермедиат
Intermediate
(ВС)
0
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
Distance С7–О1 between reaction sites, Å
Fig. 3. PES profiles for the transition intermediate С → final product 3a and 3d–3e.
350
IIIи
3i
300
250
200
150
100
50
IIIз
3h
IIIж
3g
IIIе
3f
ПTеrрaеnхsоiдtiнoоnе
состояние
state
Final
Конечный
product 3
продукт (III)
ИнIтnеtр(eВмrе)mдeиdаiтate
С
0
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
Distance С7–О1 between reaction sites, Å
Fig. 4. PES profiles for the transition intermediate С → final product 3f–3i.
Table 1. Effective rate constants (keff) and activation barriers (Eact) of the formation of compounds 3а and 3с–3e, solvent
MeOH
Structure
3а
3c
3d
3e
3f
3g
3h
3i
keff × 10–5, s–1
26
43
5.5
4.6
5.4
6.4
3.3
2.8
ln keff
–8.25
106.61
–7.75
114.62
–9.80
203.75
–9.98
192.91
–9.82
186.40
–9.65
188.81
–10.32
222.82
–10.48
208.80
Еact, kJ mol–1
the phenylacetonitrile carbanions. The obtained value
of the correlation factor (r –0.964) makes it possible to
conclude reliably that just the formation of 2,1-
benzisoxazole rings is the limiting stage of the
reaction.
For the formation of 3-phenyl-5-chloro-2,1-
benzisoxazole 3a the PES profiles for the cyclization
process were also constructed characterizing the effect
of the applied solvent. A series of lower aliphatic alco-
hols, like methanol, ethanol, propanol, 2-propanol, buta-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 2 2015

ORLOV et al.
250
–7
2
2
R 0.930
R = 0.930
Sx 43.332
IIIв
3с
–7.5
–8
Sx = 43.332
Sy 0.979
Sy = 0.979
r –0.964
r = - 0.964
–8.5
–9
IIIа
3а
IIIж
3g
–9.5
–10
–10.5
–11
3d
IIIг
3f
IIIе
IIIз
3h
3e
IIIд
3i
IIIи
100
120
140
160
180
200
220
Еact, kJ mol–1
Fig. 5. Dependence of ln keff on Еact for the structures 3а and 3c–3i with accounting for solvation (MeOH).
–5
2
2
R 0.853
R = 0.853
Sx 21.916
–5.5
–6
Sx = 21.916
Sy 0.980
S = 0.980
r –0.924
y
2-PrOH
r = - 0.924
2-PrOH
–6.5
–7
BuOH
BuOH
PrOH
PrOH
–7.5
–8
EtOH
EtOH
–8.5
–9
MeOH
MeOH
–9.5
45
55
65
75
85
95
105
115
Еact, kJ mol–1
Fig. 6. Dependence of ln keff on Еact for the compound 3а with accounting for solvation in various solvents.
nol were regarded as solvents. The calculated values of
the activation barriers of the studied stage of the chemi-
cal reaction are compiled in Table 2. Here the values
of the effective constants keff of the formation of com-
pound 3a at the use of various solvents are also listed.
of the activation barrier decreased with the increasing
polarization of the system. This is expressed in the
growing value of the dipole moment of the system
“model structure–solvent” in the series MeOH–EtOH–
PrOH–BuOH–2-PrOH, and it corresponds to the grow-
ing reaction rate. The respective values of the dipole
moments of initial structures and transition states for
the mentioned solvent series are given in Table 3.
The correlation dependence of ln keff on Еact was
found for the simulation of the effect of various
solvents on the formation of compound 3a (Fig. 6).
The observed relation also is not contradicting the
suggestion of the cyclization as the limiting stage since
it proceeds with the cleavage of ionic objects.
The analysis of the effect of the applied solvent on
the course of the target reaction showed that the value
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 2 2015

MECHANISM OF FORMATION OF 2,1-BENZISOXAZOLES IN REACTIONS
251
Table 2. Effective rate constants (keff) and activation barriers (Eact) of the formation of compound 3a in various solvents
Solvent
keff× 10–5, s–1
ln keff
MеОН
26
EtOH
30
PrOH
50
BuOH
106
2-PrOH
277
–8.25
106.61
–8.11
99.85
–7.60
98.93
–6.84
92.44
–5.88
51.75
Еact, kJ mol–1
Table 3. Values of electric dipole moments Р of the system compound 3a–solvent for initial and transition states of
cyclization stage
Solvent
Рin, D
РTS, D
eff × 10–5, s–1
MеОН
7.116
5.842
26
EtOH
8.209
7.667
30
PrOH
9.772
7.851
50
BuOH
10.950
9.471
106
2-PrOH
11.528
10.242
277
k
Thus based on experimental data and quantum
chemical calculations we developed in this study a
model describing the mechanism of the formation of 3-
phenyl-5-Х-2,1-benzisoxazoles. The analysis of the
correlations of the calculated and experimental
reaction parameters allows a conclusion that just the
cyclization in the process of the formation of the 2,1-
benzisoxazole rings in the reaction of para-substituted
nitrobenzenes with the carbanion of phenylacetonitrile
is the limiting stage governing the main reaction laws.
method (Unrestricted Hartree–Fock approximation,
parameter SCFTYP=UHF) and the basis set
6-31G(d,p). The geometry optimization was accomplished
utilizing the parameter RUNTYP=OPTIMIZE, the
Hessian calculation for the structures in question, using
RUNTYP=HESSIAN, the search for transition states,
RUNTYP=SADPOINT. The visualization of the cal-
culation results was fulfilled with software ChemCraft
1.46 [13].
2,1-Benzisoxazoles. General procedure. Sodium
hydroxide and 2-propanol were stirred for 30 min, then
arylacetonitrile and nitroaromatic compound were
charged in the molar ratio nitroarene–nitrile–NaOH
1 : 1.2 : 10. The reaction mixture was vigoriously
stirred at room temperature till the completion of the
reaction (TLC monitoring). Then the reaction mixture
was poured into water, the separated precipitate was
filtered off and washed with water. The filtrate was
treated with hydrochloric acid till acidic pH, the
separated precipitate was filtered off. The product was
purified by recrystallization from an appropriate
solvent.
EXPERIMENTAL
1H NMR spectra were registered on a spectrometer
Bruker Avance AC-300 at operating frequency
300 MHz in DMSO-d6, Internal reference TMS. IR
spectra were recorded on a Fourier spectrophotometer
Spectrum 65 from mulls in mineral oil. Mass spectra
were measured on an instrument MKh-1310. Melting
points were determined on a device PolyTherm A.
TLC was carried out on Silufol UV-254 plates,
development under UV irradiation or in iodine vapor,
eluent hexane–benzene, 3 : 7.
3-Phenyl-5-chloro-2,1-benzisoxazole (3а), mp
113–114°С (ethanol). IR spectrum, ν, cm–1: 1628
The preliminary quantum chemical modeling of
intermediates and transition states was performed
using semiempirical method РM7 applying the
program MОРАС 2012 [11]. Therewith the search for
the transition states was carried out employing the
SADDLE procedure (automated search for TS at
determined structures corresponding to the initial and
final intermediates). The geometry optimization and
the calculation of the energy parameters of the studied
compounds was performed by the program PC
GAMESS/Firefly v. 7.0 [12] using ab initio calculation
1
(C=N), 1264 (N–O). Н NMR spectrum, δ, ppm: 7.33
d (1Н, Н7), 7.52–7.65 m (3H, H3',4',5'), 7.68 d.d (1H,
Н6), 8.05 d (1Н, Н4), 8.07 d.d (2H, H2',6'). Mass
spectrum, m/z (Irel, %): 229 (72) [M]+, 194 (52), 166
(69), 139 (15), 77 (100), 51 (58).
3-(3,4-Dimethoxyphenyl)-5-chloro-2,1-benzizo-
xazole (3b), mp 142–144°C (2-propanol). IR spec-
1
trum, ν, cm–1: 1634 (C=N), 1265 (N–O). Н NMR
spectrum, δ, ppm: 3.86 s (ОСН3), 7.06 d (2H, H3',5'),
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 2 2015

ORLOV et al.
252
7.23 d (1H, H7), 7.54 d.d (1H, H6), 7.89 d (1H, H4),
7.95 d (2H, H2',6'). Mass spectrum, m/z (Irel, %): 294
(100) [M]+.
5-[4-(2-Methyl-1,3-dioxolan-2-yl)phenyl]-3-phe-
nyl-2,1-benzisoxazole (3i), mp 134–136°С (2-propa-
nol). IR spectrum, ν, cm–1: 1630 (C=N). Mass spec-
trum, m/z (Irel, %): 357 (100) [M]+.
5-Bromo-3-phenyl-2,1-benzisoxazole (3c), mp
117–118°С (ethanol). IR spectrum, ν, cm–1: 1626
[6-(Hydroxyimino)-3-chlorocyclohexa-2,4-dien-
1
(C=N), 1264 (N–O). Н NMR spectrum, δ, ppm: 7.47
1-ylidene](3,4-dimethoxyphenyl)acetonitrile (6), mp
d (H7), 7.55–7.60 m (3Н, H3',4',5'), 7.62 d.d (1H, H6),
8.08 d.d (2H, H2',6'), 8.28 d (1H, H4). Mass spectrum,
m/z (Irel, %): 275 (40) [M]+, 194 (52), 166 (75), 139
(29), 77 (100), 51 (53).
176–178°C (2-propanol). Н NMR spectrum, δ, ppm:
1
3.82 s (6Н, ОСН3), 7.02–7.43 m (6Н, С6Н3), 13.18 s
(1Н, NОH). Mass spectrum, m/z (Irel, %): 316 (2.0)
[M]+, 289 (67.2), 272 (2.2), 241 (2.1), 210 (8.3), 183
(4.9), 165 (100), 137 (13.7).
3,5-Diphenyl-2,1-benzisoxazole (3d), mp 212–
215°С (ethanol–DMF). IR spectrum, ν, cm–1: 1630
The study was carried out under the support of the
project no. 178 in the framework of the basic part of
the State contract on research for the Demidov
Yaroslavl State University.
1
(C=N), 1264 (N–O). Н NMR spectrum, δ, ppm: 7.37
d (1H, H7), 7.42 d.d (1H, H6), 7.45 d (2H, H3',5'), 7.67–
7.80 m (6H, Ph + Н4'), 7.82 d (1H, H4), 8.31 d (2H,
H
2',6'). Mass spectrum, m/z (Irel, %): 271 (100) [M]+.
3-Phenyl-5-phenoxy-2,1-benzisoxazole (3e), mp
REFERENCES
62–65°С (benzene). IR spectrum, ν, cm–1: 1266 (СОС),
1633 (C=N). 1Н NMR spectrum, δ, ppm: 7.30 d.d (2H,
Н6), 7.46 d (2H, Н4), 7.50–7.60 m (3H, H3',4',5'), 7.72 d
(2H, Н7), 7.95 d.d (2H, H2',6').
1. Davis, R.B., Pizzini, L.C., and Benigni, J.D., J. Am.
Chem. Soc., 1960, vol. 82, p. 2913.
2. Davis, R.B. and Pizzini, L.C., J. Org. Chem., 1960, vol. 25,
p. 1884.
3. Orlov, V.Yu., Kotov, A.D., Kopeikin, V.V., Orlova, T.N.,
Rusakov, A.I., and Mironov, G.S., Russ. J. Org. Chem.,
1996, vol. 32, p. 1332.
5-(1,3-Dioxolan-2-yl)-3-phenyl-2,1-benzisoxazole
1
(3f), mp 137–138oC (2-propanol). Н NMR spectrum,
δ, ppm: 4.15 t (4Н, СН2), 5.78 s (1Н, СН), 7.40 d (1H,
H7), 7.60 d.d (1H, H6), 7.65 m (3H, H3',4',5'), 7.96 d
(1H, H4), 8.10 d.d (2H, H2',6'). Mass spectrum, m/z (Irel,
%): 267 (63) [M]+, 195 (100), 167 (22), 139 (13), 105
(31), 77 (94), 51 (42).
4. Orlov, V.Yu., Kotov, A.D., Sokovikov, Ya.V., and Sta-
rikov, A.A., Russ. J. Org. Chem., 2000, vol. 36, p. 1735.
5. Orlov, V.Yu., Kotov, A.D., Kopeikin, V.V., Rusakov, A.I.,
Mironov, G.S., and Bystryakova, E.B., Russ. J. Org.
Chem., 1998, vol. 34, p. 538.
6. Orlov, V.Yu., Sokovikov, Ya.V., and Kotov, A.D.,
5-(2-Methyl-1,3-dioxolan-2-yl)-3-phenyl-2,1-ben-
zisoxazole (3g), mp 175–177°С (2-propanol). IR
spectrum, ν, cm–1: 1645 (C=N), 1239 (N–O). 1Н NMR
spectrum, δ, ppm: 1.61 s (3H, СН3), 4.02 t (4H, СН2),
7.44 d (1H, H7), 7.50–7.63 m (3H, H3',4',5'), 7.65 d.d
(1H, H6), 7.90 d (1H, H4), 8.05 d.d (2H, H2',6'). Mass
spectrum, m/z (Irel, %): 281 (27) [M]+, 266 (100), 222
(31), 194 (12), 166 (21), 139 (10), 105 (19), 87 (31),
77 (55), 51 (21).
Russ. J. Org. Chem., 2002, vol. 38, p. 100.
7. Konovalova, N.V., Kotov, A.D., Ganzha, V.V., Orlo-
va, T.N., and Orlov, V.Yu., Izv. Vuzov, Ser. Khim.
Khim. Tekhnol., 2009, vol. 52, p. 59.
8. Orlov, V.Yu., Kotov, A.D., Ganzha, V.V., and
Mironov, G.S., Russ. J. Org. Chem., 2003, vol. 39,
p. 1674.
9. Orlov, V.Yu., Kotov, A.D., and Ganzha, V.V., Russ.
J. Org. Chem., 2003, vol. 39, p. 1362.
3-Phenyl-2,1-benzisoxazole-5-carboxylic acid
10. Orlov, V.Yu., Kotov, A.D., Tsivov, A.V., and
Andreeva, K.V., Izv. Vuzov, Ser. Khim. Khim. Tekhnol.,
2011, vol. 54, p. 41.
11. Molecular Orbital Package–MOPAC. http://
www.openmopac.net/.
12. Granovsky, A.A., Firefly. http://classic.chem.msu.su/
(3h), mp 248–250°С (АсОН). IR spectrum, ν, cm–1:
1
2640 (OH), 1704 (C=O). Н NMR spectrum, δ, ppm:
7.60 m (3H, H3',4',5'), 7.62 d (1H, H7), 7.85 d.d (1H,
H6), 8.04 d.d (2H, H2',6'), 8.61 d (1H, H4), 13.05 br.s
(1H, СООН). Mass spectrum, m/z (Irel, %): 239 (100)
[M]+, 222 (17), 194 (24), 166 (39), 139 (18), 105 (21),
77 (100), 51 (43).
gran/gamess/index.html.
13. ChemCraft. http://www.chemcraftprog.com/.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 2 2015