Reactions of aliphatic diazo compounds: IV. Reaction of diphenyldiazomethane with substituted imides of maleic and itaconic acids

Article abstract of DOI:10.1023/A:1015582104282

Diphenyldiazomethane regioselectively adds to 2-R-substituted maleimides to yield 1-pyrazoline derivatives, 1-R-7-aryl-6,8-dioxo-4,4-diphenyl-2,3,7-triazabicyclo[3.3.0]oct-2-enes that on heating liberate nitrogen to afford substituted 3-azabicyclo[3.1.0]h

Full text of DOI:10.1023/A:1015582104282

Russian Journal of Organic Chemistry, Vol. 38, No. 2, 2002, pp. 259 263. Translated from Zhurnal Organicheskoi Khimii, Vol. 38, No. 2, 2002,
pp. 281 285.
Original Russian Text Copyright
2002 Molchanov, Diev, Kostikov.
Reactions of Aliphatic Diazo Compounds: IV.
Reaction of Diphenyldiazomethane with Substituted
Imides of Maleic and Itaconic Acids
A. P. Molchanov, V. V. Diev, and R. R. Kostikov
St. Petersburg State University, St. Petersburg, 198504 Russia
Received June 21, 2001
Abstract Diphenyldiazomethane regioselectively adds to 2-R-substituted maleimides to yield 1-pyrazoline
derivatives, 1-R-7-aryl-6,8-dioxo-4,4-diphenyl-2,3,7-triazabicyclo[3.3.0]oct-2-enes that on heating liberate
nitrogen to afford substituted 3-azabicyclo[3.1.0]hexanes. To the N-arylsubstituted imides of itaconic acid
the diphenyldiazomethane adds to furnish 5-aryl-4,6-dioxo-1,1-diphenyl-5-azaspiro[2.4]heptanes.
Reactions of diazoalkanes with unsaturated com-
pounds containing an activated multiple bond result
in 1- or 2-pyrazolines depending on the structure of
the diazo compound. It was shown formerly that alkyl
diazoacetates added to maleimides regioselectively to
afford 2-pyrazolines [2, 3]. The reaction of diazo-
methane with N-phenylmaleimide gave rise to a sub-
stituted 1-pyrazoline [4]. To the reaction product of
diphenyldiazomethane and N-phenylmaleimide was
assigned a structure of 2-pyrazoline [5] and not
1-pyrazoline as had been reported before [2]. In
reaction of diphenyldiazomethane with N-phenylimide
of citraconic acid was isolated only a substituted
cyclopropane, and the regioselectivity of the addition
was not established [2]. The reaction between diazo
compounds and imides of itaconic acid was not
investigated.
region (J 8 Hz) and a doublet from the proton linked
to C1 in a weaker field at 6.53 6.60 ppm (J 8 Hz).
The downfield shift of the signal from the proton at
C1 evidences that this atom is located in 3 position
1
of 1-pyrazoline. In the H NMR spectra of pyrazo-
lines IVa d appears a singlet in the 4.08 4.28 ppm
region; this proton is consequently attached to C5
atom, and the compounds IV obtained have the struc-
ture of 1-pyrazolines.
In this study were investigated reactions of
diphenyldiazomethane with N-arylsubstituted male-
imides Ia h, maleimides IIa p containing a methyl
or aryl substituent at the double C=C bond, and
substituted imides of itaconic acid VIIa d. The reac-
tion of diphenyldiazomethane with imides Ia h in
dichloromethane at room temperature afforded 6,8-di-
oxo-4,4-diphenyl-2,3,7-triazabicyclo[3.3.0]oct-2-enes
(IIIa h). The composition and the structure of
pyrazolines IIIa h were established from elemental
analyses (Table 1) and spectral data (Table 2).
I, III, V, R = H, R = Ph (a), 4-CH3C6H4 (b),
4-ClC6H4 (c), 4-BrC6H4 (d), 4-NO2C6H4 (e), 2-ClC6H4
(f), 2-CH3OC6H4 (g), 2,4-(CH3)2C6H3 (h); II, IV, VI,
R = Me, R = Ph (a), 4-CH3C6H4 (b), 4-ClC6H4 (c),
2-ClC6H4 (d), 3-CF3C6H4 (e), 3-BrC6H4 (f); R = R =
Ph (g); R = Ph, R = 4-CH3C6H4 (h), 4-ClC6H4 (i);
R = 4-CH3C6H4, R
= Ph (j), 4-CH3C6H4 (k),
4-ClC6H4 (l), 2-ClC6H4 (m); R = 4-ClC6H4, R = Ph
(n), 4-CH3C6H4 (o), 4-ClC6H4 (p).
In the IR spectrum of pyrazoline IIIa appears an
1
absorption band of C=O group (1720 cm ) and lacks
1
the absorption band of NH group. In the H NMR
1-Pyrazolines IIIa h and IVa d readily loose
nitrogen already at room temperature, and the sub-
stances obtained contain a little of cyclopropane
compounds impurities. On heating pyrazolines IIIa h
spectra of pyrazolines IIIa h are present doublet
signals from hydrogen atoms attached to the bridge-
head carbons: C5H-doublet in the 4.1 4.21 ppm
1070-4280/01/3802-259$27.00 2002 MAIK Nauka/Interperiodica

260
MOLCHANOV et al.
Table 1. Yields, melting points, and elemental analyses of compounds IIIa, IVb, Vc g, VIa p, VIIIa d
Found, %
H
Calculated, %
Compd.
no.
Yield,
%
mp,
oC
Formula
C
N
C
H
N
IIIa
IVb
Vc
Vd
Ve
93
55
95
90
50
83
70
78
41
83
46
68
80
43
85
68
87
62
68
36
88
66
64
64
88
66
75
143a
135a
170
206
209
205
190
189
191
156
195
151
169
105
104
175
99
75.26
74.10
74.15
65.87
72.03
73.74
75.84
81.53
81.57
74.41
74.37
71.37
66.82
83.98
83.69
77.51
83.81
84.06
77.76
77.51
77.16
77.43
71.79
81.51
81.38
74.27
74.42
4.75
5.26
4.41
3.91
4.45
4.52
4.79
5.42
5.86
4.65
4.74
4.50
4.44
5.22
5.61
4.60
5.52
5.88
4.89
4.91
4.63
5.00
4.08
5.45
5.72
4.69
4.75
11.45
10.35
3.84
3.54
7.05
3.97
3.92
3.87
3.63
3.38
3.39
3.32
3.20
3.26
3.15
2.78
3.11
2.92
2.73
2.46
2.94
2.73
2.55
3.84
3.72
3.41
3.53
C23H17N3O2
C20H20N2O3
C23H16ClNO2
C23H16BrNO2
C23H16N2O4
C23H16ClNO2
C24H19NO3
75.19
73.93
73.90
66.04
71.87
73.90
75.58
81.56
81.72
74.32
74.32
71.25
66.68
83.83
83.89
77.42
83.89
83.95
77.66
77.66
77.42
77.66
71.91
81.56
81.72
74.32
74.32
4.66
5.35
4.31
3.86
4.20
4.31
5.02
5.42
5.76
4.68
4.68
4.31
4.20
5.09
5.40
4.48
5.40
5.68
4.78
4.78
4.48
4.78
3.95
5.42
5.72
4.68
4.68
11.44
10.63
3.74
3.35
7.28
3.74
3.67
3.96
3.81
3.61
3.61
3.32
3.24
3.37
3.26
3.11
3.26
3.16
3.02
3.02
3.11
3.02
2.89
3.96
3.72
3.61
3.61
Vf
Vg
VIa
VIb
VIc
VId
VIe
VIf
VIg
VIh
VIi
C24H19NO2
C25H21NO2
C24H18ClNO2
C24H18ClNO2
C25H18F3NO2
C24H18BrNO2
C29H21NO2
C30H23NO2
C29H20ClNO2
C30H23NO2
VIj
VIk
VIl
173
201
236
199
206
207
192
178
212
188 195
C31H25NO2
C30H22ClNO2
C30H22ClNO2
C29H20ClNO2
C30H22ClNO2
C29H19Cl2NO2
C24H19NO2
C25H21NO2
C24H18ClNO2
C24H18ClNO2
VIm
VIn
VIo
VIp
VIIIa
VIIIb
VIIIc
VIIId
a
With decomposition.
in toluene to 110 C for 1 h, and pyrazolines IVa d in
benzene to 80 C for 1.5 h a nitrogen evolution was
observed, and 3-azabicyclo[3.1.0]hexanes Va h and
VIa d were obtained in good yield. In reactions of
diphenyldiazomethane with maleimides containing
aromatic substituents at the double bond we in most
cases failed to detect 1-pyrazolines: when the reaction
was carried out at room temperature only the cor-
responding cyclopropane derivatives VIg p were
isolated. From reaction products of diphenyldiazo-
methane and imide IIh we isolated a mixture of
cyclopropane Vh with a compound that was assigned
a structure of 1-pyrasoline IVh basing on the
In the IR spectra of compounds V and VI appears
1
the absorption band of C=O group (1710 cm ).
1
In the H NMR spectra of products Va h and VIa f
the singlet signal of cyclopropane protons is observed
in 3.35 3.65 ppm region, and of compounds VIg p
with aryl substituents in position 1 this signal is
shifted downfield to 4.00 ppm. Physical constants of
compounds Va, b, h are in agreement with the
published data [2].
The reaction of diphenyldiazomethane with the
ortho-substituted maleimides If, g, IId due to the
hindered rotation of the ortho-substituted aryl group
around the bond N Carom gives rise to two conforma-
tional forms of pyrasolines IIIf, g and IVd in the
ratios 1.6 : 1, 1.2 : 1, and 1.2 : 1 for compounds IIIf,
IIIg, and IVd respectively. The signals from hydro-
gen atoms at the bridgehead carbons appear downfield
1
presence in its H NMR spectrum of a singlet at
4.67 ppm. The composition and structure of com-
pounds Va h and VIa p were established from the
elemental analyses (Table 1) and spectral data
(Table 2).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 2 2002

REACTIONS OF ALIPHATIC DIAZO COMPOUNDS: IV.
261
Table 2. IR and 1H NMR spectra of compounds IIIa g, IVa d, Va h, VIa p, VIIIa d
Compd.
no.
1
IR spectrum, cm
1H NMR spectrum, , ppm (J)
IIIa 1185, 1235, 1380 s, 1450, 1500, 4.18 d (1H, 8), 6.55 d (1H, 8), 6.73 6.80 (4H), 7.25 7.58 (9H),
1600, 1720 v.s, 1800, 3070
7.72 7.78 (2H)
IIIb
IIIc
2.28 s (3H), 4.16 d (1H, 8), 6.53 d (1H, 8), 6.65 6.73 (4H), 7.15 7.58
(8H), 7.73 d (2H, 8)
4.17 d (1H, 8), 6.54 d (1H, 8), 6.73 d (2H, 7), 6.83 d (2H, 8), 7.31 7.58
(8H), 7.74 d (2H, 8)
IIId
IIIe
4.17 d (1H, 8), 6.54 d (1H, 8), 6.71 6.78 (4H), 7.27 7.93 (10H)
4.21 d (1H, 8), 6.60 d (1H, 8), 6.74 · (2H), 7.10 d (2H, 9), 7.28 7.60
(6H), 7.76 d (2H, 7), 8.28 d (2H, 9)
IIIf
IIIg
IVa
4.35 d, 4.53 d (1H, 8), 6.48 d, 6.74 d (1H, 8), 6.55 d, 6.84 d (1H, 8),
6.98 m (1H), 7.27 7.65 (10H), 7.77 d (2H, 8)
3.72 s, 3.74 s (3H), 4.27 d, 4.44 d (1H, 8), 6.29 d, 6.77 d (1H, 8), 6.38 d,
6.67 d (1H, 8), 6.93 7.60 (11H), 7.76 d (2H, 8)
1.80 s (3H), 4.10 s (1H), 6.78 m (2H), 6.89 m (2H), 7.28 7.75 (11H)
IVb 1130, 1240 s, 1370 s, 1385 s, 1.97 s (3H), 2.33 s (3H), 3.68 s (1H), 6.58 d (2H, 8), 6.90 m (2H), 7.13 d
1450, 1525, 1600, 1710 v.s, 3055 (2H, 8), 7.30 7.60 (6H), 7.85 d (2H, 8)
IVc
IVd
Va
1.79 s (3H), 4.08 s (1H), 6.76 d (2H, 8), 6.95 d (2H, 8), 7.35 7.60 (8H),
7.70 d (2H, 8)
1.61 s, 1.84 s (3H), 4.28 s, 4.50 s (1H), 6.51 d (0.5H, 7), 6.80 d (1H, 8),
6.95 d (1H, 8), 7.20 7.70 (11.5H), 7.78 d (1H, 8)
1190, 1240, 1390 s, 1450, 1505, 3.35 s (2H), 6.38 m (2H), 7.20 7.43 (11H), 7.55 m (2H)
1600, 1710 v.s, 1785, 3035, 3070
Vb
Vc
1979, 1190, 1240, 1390 s, 1450, 2.28 s (3H), 3.33 s (2H), 6.22 d (2H, 8), 7.05 d (2H, 8), 7.25 7.42 (8H),
1520, 1600, 1710 v.s, 1785, 3060 7.57 m (2H)
1020, 1070, 1100, 1185, 1230, 3.35 s (2H), 6.31 d (2H, 8), 7.21 d (2H, 8), 7.25 7.43 (10H), 7.55 m
(2H) 1385s, 1450, 1495s, 1600,
1710v.s, 1785, 3070
Vd
Ve
1020, 1075, 1190, 1230, 1385 s, 3.34 s (2H), 6.26 d (2H, 8), 7.23 7.37 (10H), 7.55 m (2H)
1450, 1490s, 1600, 1710v.s, 1785, 3070
1070, 1180, 1230, 1335 s, 1385 s, 3.40 s (2H), 6.67 d (2H, 8), 7.27 7.42 (8H), 7.55 m (2H), 8.10 d (2H, 8)
1450, 1500, 1530, 1600, 1710 v.s,
1785,
2960,
3030
Vf
1075, 1190, 1230, 1385 s, 1450, 3.40 s (2H), 5.18 d (1H, 8), 7.00 m (1H), 7.25 7.47 (10H), 7.60 m (2H)
1490 s, 1600, 1715 v.s, 1785, 3070
Vg
1035, 1075, 1125, 1190, 1260, 1285, 3.35 s (2H), 3.79 s (3H), 5.18 d (1H, 8), 6.65 m (1H), 6.92 d (1H, 8),
1390s, 1465, 1505, 1600, 1710 v.s, 7.25 7.45 (9H), 7.58 m (2H)
1785, 1785, 3060
Vh
1075, 1190, 1230, 1385 s, 1450, 2.13 s(3H), 2.27 s (3H), 3.35 s (2H), 4.90 d (1H, 8), 6.71 d(1H, 8), 7.03 m
1505, 1600, 1710 v.s, 1785, 3050 (1H), 7.26 7.48 (8H), 7.60 m (2H)
VIa 1140, 1240, 1390 s, 1450, 1500, 1.50
1600, 1710 v.s, 1785, 3070
VIb 1140, 1235, 1390 s, 1450,
s
(3H), 3.28
7.30 7.55 (9H), 7.87 m (2H)
1.49 s (3H), 2.28 s (3H), 3.25 s (1H), 6.20 d (2H, 8), 7.03 d
s
(1H), 6.73
m
(2H), 6.88
m
(2H),
1520, 1600, 1710 v.s, 1785, 3040 (2H, 8), 7.25 7.55 (10H)
VIc 1020, 1100 s, 1140 s, 1240, 1.49
1390 s, 1450, 1500 s, 1600,
1710 v.s, 1780, 3065
s (3H), 3.28 s (1H), 6.30 d (2H, 8), 7.18 7.39 (12H)
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 2 2002

262
MOLCHANOV et al.
Table 2. (Contd.).
Compd.
no.
1
IR spectrum, cm
1H NMR spectrum, , ppm (J)
1.52 s (3H), 3.32 s (1H), 5.15 d.d (1H, 8, 1), 7.00 m (1H),
VId 1140, 1270, 1390 s, 1450,
1490 s, 1600, 1710 v.s, 1785, 3070 7.20 7.50 (10H), 7.58 m (2H)
3070
VIe 1080, 1140, 1180, 1230, 1330 s, 1.36 s (3H), 3.68 s (1H), 6.33 s (1H), 6.81 d (1H, 8), 7.37 7.70 (12H)
1390, 1445, 1495, 1710 v.s, 1785,
VIf
3070, 1080, 1140 s, 1230, 1385 s, 1.35 s (3H), 3.65 s (1H), 6.28 s (1H), 6.42 d (1H, 8), 7.22 7.58 (12H)
1460,1480, 1590, 1710 v.s, 1785,
3070
VIg
1140, 1180, 1240, 1385 s, 1450, 4.01 s (1H), 6.37 m (2H), 7.03 7.75 (18H)
1500, 1600 s, 1710 v.s, 1785, 3070
VIh
VIi
1140, 1185, 1235, 1390 s, 1450, 2.29 s (3H), 4.00 s (1H), 6.23 d (2H, 8), 7.00 7.72 (17H)
1510, 1600, 1710 v.s, 1785, 3040
1020, 1100, 1140, 1180, 1240, 1385 s, 4.01 s (1H), 6.33 d (2H, 9), 7.00 7.72 (17H)
1450, 1500s, 1600, 1710 v.s, 1785,
3070
VIj
VIk
VIl
1140, 1185, 1240, 1390s, 1450, 1520, 2.29 s (3H), 3.97 s (1H), 6.37 m (2H), 7.03 7.48 (15H), 7.70 m (2H)
1600, 1710 v.s, 1785, 3065
1140, 1185, 1240, 1390 s, 1450, 2.28 s (3H), 2.29 s (3H), 3.95 s (1H), 6.23 d (2H, 8), 7.00 7.18 (9H),
1520, 1600, 1710 v.s, 1785, 3050 7.37 7.47 (5H), 7.68 d (2H, 8)
1020, 1100, 1140, 1180, 1240, 1385 s, 2.29 s (3H), 3.96 s (1H), 6.32 d (2H, 8), 7.02 7.26
1450, 1495s, 1600, 1710 v.s, 1785, (9H), 7.32 7.45 (5H), 7.74 m (2H)
3060
VIm
VIn
VIo
1140, 1180, 1390s, 1450, 1485, 1600, 2.29 s (3H), 4.00 s (1H), 5.22 d (1H, 7), 7.00 7.53 (15H), 7.70 m (2H)
1710 v.s, 1790, 3050
1020, 1140, 1180, 1240, 1390s, 1450, 3.99 s (1H), 6736 m (2H), 7.03 7.52 (15H), 7.67 m (2H)
1500 s, 1600, 1710 v.s, 1785, 3070
1020, 1100, 1140, 1185, 1240, 1385 s, 2.29 s (3H), 3.97 s (1H), 6.23 d (2H, 9), 7.00 7.50 (14H), 7.68 m (2H)
1450, 1500, 1600, 1710 v.s, 1785,
3050
VIp
1020, 1100 s, 1140, 1180, 1240, 3.99 s (1H), 6.32 d (2H, 8), 7.03 7.50 (14H), 7.67 m (2H)
1385 s, 1450, 1495 s, 1600,
1710 v.s, 1785, 3070
VIIIa 1140s, 1190, 1240, 1385, 1460, 1505, 2.15 d (1H, 5), 2.49 d (1H, 5), 2.71 d (1H, 19), 2.89 d (1H, 19), 7.18
1600, 1710 v.s, 1785, 3070 7.53 (15H)
VIIIb 1140, 1190, 1240, 1385 s, 1460, 1520, 2.14 d (1H, 5), 2.38 s (3H), 2.48 d (5), 2.69 d (1H, 19), 2.88 d (1H, 19),
1600, 1710 v.s, 1785, 3050 7.17 7.45 (14H)
VIIIc 1020, 1100, 1140 s, 1190, 1240, 2.16 d (1H, 5), 2.49 d (1H, 5), 2.69 d (1H, 19), 2.88 d (1H, 19), 7.22
1380 s, 1460, 1500 s, 1600, 7.47 (14H)
1710 v.s, 1790, 3060
VIIId 1070, 1145, 1190, 1235, 1385s, 1450, 2.15 d, 2.16 d (1H, 5), 2.49 d, 2.53 d (1H, 5), 2.71 d, 2.80 d (1H, 19),
1490 s, 1600, 1720 v.s, 1790, 3070 2.91 d, 2.98 d (1H, 19), 7.14 7.60 (14H)
for the prevailing isomer, as follows: for compound
IIIf at 4.35 d (J 8 Hz) and 4.53 d (J 8 Hz), for com-
pound IIIg at 4.27 d (J 8 Hz) and 4.44 d (J 8 Hz), for
compound IVd at 4.28 s and 4.50 s. At the same time
cyclopropane compounds Vf, g, h, and VId, m with
ortho-substituents in the aromatic ring of the imide
moiety form a single isomer, presumably with anti-
configuration due to strong sterical interactions
between the ortho-substituted aromatic ring and the
aromatic substituent located at the three-membered
cycle in the syn-configuration. Due to the strong
screening effect of phenyl group exerted on the ortho-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 2 2002

REACTIONS OF ALIPHATIC DIAZO COMPOUNDS: IV.
263
protons of the benzene ring attached to the imide
moiety the signals of these protons in the H NMR
spectra appear in 4.90 5.22 ppm region. A similar
upfield shift of the signal from ortho-protons of
benzene ring due to the screening effect of a phenyl
group was observed in imides prepared by reaction
of anthracene with ortho-substituted maleimides [6].
N-arylmaleimide (Ia h) or N-arylimide of citraconic
acid (IIa d) in 10 ml of dichloromethane was added a
solution of 1 g (5 mmol) of diphenyldiazomethane in
10 ml of dichloromethane, The mixture was kept for
2 4 days till disappearance of the diphenyldiazo-
methane color. The separated precipitate was filtered
off and washed with ethanol.
1
At treating N-arylsubstituted imides of itaconic
acid VIIa d with diphenyldiazomethane in dichloro-
methane at 18 20 C we failed to isolate the inter-
mediately arising pyrazolines. In the course of reac-
tion nitrogen is liberated, and substituted 5-azaspiro-
[2.4]heptanes (VIII d) form in good yield.
3-Aryl-2, 4-dioxo-6,6-diphenyl-3-azabicyclo-
[3.1.0]hexanes (Va h). A mixture of 4 mmol of
pyrazoline IIIa h and 10 ml of toluene was heated to
100 C for 1 h. The pyrazoline gradually dissolved.
The toluene was distilled off in a vacuum, the
separated precipitate was recrystallized from ethanol.
3-Aryl-1-methyl-6,6-diphenyl-3-azabicyclo[3.1.0]-
hexanes (VIa f). A mixture of 0.7 mmol of pyr-
azoline IVa f with 5 ml of benzene was heated to
80 C for 1.5 h. The pyrazoline gradually dissolved
in the course of heating. Then benzene was vacuum-
evaporated, and the residue was crystallized from
ethanol.
VII, VIII, R = H (a), 4-Me (b), 4-Cl (c), 2-Cl (d).
1,3-Diaryl-6,6-diphenyl-3-azabicyclo[3.1.0]-
hexanes (VIg p). To a solution of 0.5 mmol of imide
IIg p in 5 ml of dichloromethane was added 0.1 g
(0.5 mmol) of diphenyldiazomethane in 5 ml of di-
chloromethane. The mixture was kept for 3 4 days at
room temperature till disappeared the color of di-
phenyldiazomethane, then the solvent was vacuum-
evaporated, and the residue was recrystallized from
ethanol.
In the IR spectra of compounds obtained is present
1
an absorption band of C=O group (1710 cm ), in the
1H NMR spectra appear doublet signals of the protons
in the cyclopropane ring in the 2.15 and 2.50 ppm
region (J 5 Hz), and doublets of protons attached to
C7 atom at 2.70 and 2.90 ppm (J 19 Hz). Unlike
ortho-substituted bicyclohexanes Vf, g, h and VId, m
that were obtained as single stereoisomers, spiro-
heptane VIIId arose as two stereoisomers.
5-Aryl-4,6-dioxo-1,1-diphenyl-5-azaspiro[2.4]-
heptanes (VIIIa d). To a solution of 0.5 mmol of
imide VIIa d in 5 ml of dichloromethane was added
a solution of 0.1 g (0.5 mmol) of diphenyldiazo-
methane. The reaction mixture was kept at room
temperature for 48 h, the solvent was evaporated, and
the residue was crystallized from benzene ethanol
mixture.
Thus it is presumable that the reaction between
diphenyldiazomethane and substituted maleimides
occurs regioselectively to afford 1-pyrazolines which
at heating liberate nitrogen to form 3-azabicyclo-
[3.1.0]hexanes; the substituents at the multiple bond
facilitate the process. In reaction of diphenyldiazo-
methane with imides of itaconic acid the intermediate
1-pyrazolines decompose with nitrogen evolution
already at room temperature forming substituted spiro-
heptanes.
REFERENCES
1. Molchanov, A.P., Lykholai, A.N., Kostikov R.R.,
Zh. Org. Khim., 2001, no. 11, pp. 1593 1597.
2. Mustafa, A., Zayed, S.M.A.D., and Khattab S., J. Am.
Chem. Soc., 1956, vol. 78, no. 1, pp. 145 149.
3. Molchanov, A.P., Ctepakov, A.V., and Kostikov, R.R.,
Zh. Org. Khim., 2000, vol. 36, no. 8, pp. 1175 1179.
4. Awad, W.I., Abdel, S.M., Omran, R., and Sobhy, M.,
J. Org. Chem., 1961, vol. 26, no. 10, pp. 4126 4128.
5. Baltzly, B., Mehta, N.B., Russel, P.B., Brooks, R.E.,
Grivsky, E.M., and Steinberg, A.M., J. Org. Chem.,
1961, vol. 26, no. 10, pp. 3669 3676.
EXPERIMENTAL
IR spectra were recorded on spectrophotometer
UR-20 from 2% solutions of compounds in chloro-
1
form. H NMR spectra were registered on spectro-
meter Bruker DPX-300 (300 MHz) from 2% solu-
tions in CDCl3 or DMSO-d6.
7-Aryl-6,8-dioxo-4,4-diphenyl-2,3,7-triazabi-
cyclo[3.3.0]oct-2-enes(IIIa h), and 7-aryl-1-methyl-
6,8-dioxo-4,4-diphenyl-2,3,7-triazabicyclo[3.3.0]-
oct-2-enes (IVa f). To a solution of 5 mmol of
6. Verma, S.M. and Singh, N.B., Aust. J. Chem., 1976,
vol. 29, mo. 2, pp. 295 300.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 2 2002