Synthesis, UV-Vis spectra, and Hammett correlation of some novel bis(dihydropyrrolo[3,4-c]pyrazoles)

Article abstract of DOI:10.1007/s00706-010-0351-z

Twenty-nine novel bis(dihydropyrrolo[3,4-c]pyrazole) derivatives were obtained by reacting C, N-phenyl-substituted nitrilimines generated in situ from corresponding hydrazonyl chlorides with bismaleimides. The structures were elucidated by physical and spectroscopic methods [m.p., R_f, infrared (IR),¹H nuclear magnetic resonance (NMR), ¹³C NMR, correlation spectroscopy (COSY), heteronuclear correlation (HETCOR), nuclear Overhauser effect (NOE), and high-resolution mass spectrometry (HRMS)]. Also, Hammett correlation graphs were obtained between Hammett constants σ_p and λ_max values of bis(pyrrolopyrazoles) carrying p-substituted phenyl-ring-bearing electron-withdrawing and electrondonating groups and discussed in terms of substituent effects. Springer-Verlag 2010.

Full text of DOI:10.1007/s00706-010-0351-z

Monatsh Chem (2010) 141:961–973
DOI 10.1007/s00706-010-0351-z
ORIGINAL PAPER
Synthesis, UV–Vis spectra, and Hammett correlation
of some novel bis(dihydropyrrolo[3,4-c]pyrazoles)
•
Yas¸ar Du¨ru¨st Muhammet Yıldırım
Received: 30 October 2009 / Accepted: 11 June 2010 / Published online: 6 July 2010
Ó Springer-Verlag 2010
Abstract Twenty-nine novel bis(dihydropyrrolo[3,4-
c]pyrazole) derivatives were obtained by reacting C,
N-phenyl-substituted nitrilimines generated in situ from
corresponding hydrazonyl chlorides with bismaleimides.
The structures were elucidated by physical and spectro-
scopic methods [m.p., Rf, infrared (IR), 1H nuclear
magnetic resonance (NMR), 13C NMR, correlation spec-
troscopy (COSY), heteronuclear correlation (HETCOR),
nuclear Overhauser effect (NOE), and high-resolution mass
spectrometry (HRMS)]. Also, Hammett correlation graphs
were obtained between Hammett constants rp and kmax
values of bis(pyrrolopyrazoles) carrying p-substituted
phenyl-ring-bearing electron-withdrawing and electron-
donating groups and discussed in terms of substituent
effects.
frequently generated in situ and used in numerous
1,3-dipolar cycloadditions. They are well known to undergo
three types of reactions: 1,3-dipolar cycloaddition leading
to five-membered ring heterocycles, cyclocondensation
reactions leading to five-membered, six-membered or lar-
ger heterocycles, and nucleophilic addition leading to
acyclic adducts, some of which were reported to show
biological activities [23–26].
Experimental observations showed that the orientation
observed for alkenes substituted with electron-donor, con-
jugating, and moderate electron-acceptor substituents is the
5-substituted regioisomer [27, 28]. Sometimes, cycloaddi-
tion of nitrilimines to very electron-deficient alkenes gives
significant amounts of the 4-substituted 2-pyrazolines [29].
The rationalization of such regiochemical results became
evident in terms of the frontier molecular orbital theory of
Fukui [30–39].
Keywords 1,3-Dipolar cycloaddition ꢀ Nitrilimine ꢀ
Bismaleimide ꢀ Heterocycles ꢀ Spectroscopy
In addition, bismaleimides have received increasing
attention recently, especially in synthesis of polymeric
materials [40–44], and molecules derived from the reaction
of bismaleimides [45] have often been studied as DNA
minor-groove-binding ligands. These types of molecules
were also reported to exhibit antitumor activity [46–49].
To the best of our knowledge, based on literature search
of SciFinder Scholar, Web of Knowledge, and Beilstein
Crossfire databases, there is no reported study related to
synthesis of bis(dihydropyrrolopyrazoles) through double
cycloaddition of diaryl nitrilimines to bismaleimides. We
aimed in this work to assemble bis(dihydropyrrolopyra-
zoles) by reacting various C,N-substituted nitrilimines
bearing both electron-withdrawing and electron-donating
groups on phenyl rings attached to the hydrazone azome-
thine carbon and hydrazone-N2, which were produced
in situ, with bis(N-phenylmaleimides) as dipolarophilic
reagents.
Introduction
Nitrilimines, which were discovered by Huisgen and
coworkers in 1959, are important precursors of 1,3-dipolar
structure, which can be used to assemble a wide variety of
five-membered heterocyclic compounds (pyrazoles,
pyrazolines) with 1,3-dipolar cycloaddition reactions to
various dipolarophiles [1–22]. Nitrilimines have been
Y. Du¨ru¨st (&) ꢀ M. Yıldırım
Department of Chemistry,
_
Abant Izzet Baysal University, Bolu, Turkey
e-mail: yasardurust@ibu.edu.tr
123

962
Y. Du¨ru¨st, M. Yıldırım
Results and discussion
acetonitrile at room temperature to afford bis(dihydropyr-
rolo[3,4-c]pyrazoles) 11, 12, 13 in excellent yields without
need for chromatographic separation (Scheme 3).
Substituted hydrazones 3a–3k and substituted hydrazonyl
chlorides 4a–4k were obtained, starting from the corre-
sponding aldehydes and substituted hydrazines (or
hydrochlorides) according to literature procedures [50–54]
(Scheme 1), and bismaleimides 8, 9, 10 (Scheme 2) were
prepared by procedures reported previously [55–59].
C,N-aryl nitrilimines generated from hydrazonyl chlo-
rides 4 in situ cycloadded to bismaleimides 8, 9, 10 in dry
The reactions were monitored by thin-layer chroma-
tography (TLC) and found to result in single diastereomers.
Since the 1,3-dipolar component of the reaction is neces-
sarily unsymmetrical, we may expect the possibility of two
diastereomers due to double cycloaddition. However, no
indication of another diastereomer was found upon
checking the 1H NMR spectra of the crude reaction mixture
or upon monitoring the progress of the reaction by TLC.
All of the new compounds were identified by means of
spectroscopic and physical data including IR, NMR, and
HRMS measurements, and CHN analyses. The cycload-
ducts 11, 12, and 13 showed strong carbonyl absorptions at
around 1,720 cm-1 and C=N absorptions at around 1,595–
1,600 cm-1 in the IR spectra.
R
O
H
EtOH, H2O
RT, 1h
R
NHNH2.HCl
+
N
N
H
H
1
3
2
NCS-DMS
4a
: R=H
4g
: R=NO2
4h: R=OCH3
0 to -40 °C,
4b : R=Cl
2-4 h, CH2Cl2
4c
: R=Br
4d : R=F
4i
: R=SCH3
4j : R=CF3
Assignment of the structures 11, 12, and 13 was per-
1
4e
4f
: R=CH3
: R=CN
4k: R=OCOCH3
formed based on data obtained from H NMR, 13C NMR,
R
COSY, HETCOR, and NOE spectra. Many attempts to
obtain fine crystals to obtain a better view of the absolute
configurations of the cycloadducts by means of X-ray
diffraction were performed, but all failed. The relative
stereochemistry of the cycloadducts was assigned to be all
cis based on the coupling constants of the bridge protons
(3a-H/3a0-H and 6a-H/6a0-H) resonating at around 5.20–
5.50 ppm as two doublets (J = 11.0 Hz) and COSY,
HETCOR, DEPT, and NOE experiments. The chemical
shifts of 3a-H/3a0-H bridge protons showed remarkable
differences compared with bridge protons 6a-H/6a0-H due
to the p-substitution of the electron-withdrawing and
electron-releasing groups on the phenyl ring attached to the
azomethine carbon. In addition, NOE experiments showed
strong enhancements by irradiation of the bridge protons
N
N
H
Cl
4
Scheme 1
O
O
1. Maleic anhydride
acetone, 2h, RT
Ar
N
N
H2N Ar
NH2
2. NaOAc,
Acetic anhydride,
95-100 oC, 30 min
O
O
5
8
9
Ar= -Ph-CH2-Ph-
6 Ar= -Ph-O-Ph-
7 Ar= -Ph-
Ar= -Ph-CH2-Ph-
Ar= -Ph-O-Ph-
10 Ar= -Ph-
Scheme 2
O
O
R
Ar
N
N
R
O
O
O
N
8
Ar= -Ph-CH2-Ph-
Ar= -Ph-O-Ph-
O
H
H
9
3a'
6a'
10 Ar= -Ph-
R
N
R
3a
6a
Et3N
N
N
Ar
N
N
N
N
N
H
-HCl
N
CH3CN
Room temp, 2-4 h
H
O
O
H
Cl
11, 12, 13
4
13
11 Ar= -Ph-CH2-Ph-
12 Ar= -Ph-O-Ph-
Ar= -Ph-
: R= H
11a
12a
13a
13b: R= Cl
13c
: R= H
11b: R= Cl
11c
: R= H
12b: R=Cl
12c
: R= Br
: R=Br
: R= Br
11d: R= F
12e: R=CH3
13e: R= CH3
11e: R= CH3
12f: R=CN
13f: R= CN
11f
12g
13g
:
R= CN
11g: R= NO2
11h
: R=NO2
12h: R=OCH3
12j
: R= NO2
13h: R= OCH3
13j
: R= OCH3
:
R=CF3
:
R= CF3
11i: R= SCH3
12k: R=OCOCH3
13k: R= OCOCH3
11j: R= CF3
11k
: R=OCOCH3
Scheme 3
123

Synthesis, UV–Vis spectra, and Hammett correlation
963
Fig. 1 Typical NOE difference spectrum of 12a, indicating strong enhancement of 3a-H (3a0-H)
Fig. 2 Typical NOE difference spectrum of 12a, indicating strong enhancement of 6a-H (6a0-H)
3a-H and 3a0-H, and 6a-H and 6a0-H, confirming their cis
stereochemistry (Figs. 1, 2). This conformation is in accord
with the structure reported by Noguchi et al. [60] for a
similar structure.
groups NO2 and CN in para positions, which remarkably
diminish the electron density on the azomethine carbon
bonded to carbon with bridge hydrogen (3a-H/3a0-H). The
distinct doublets at the specified chemical shift positions
may be considered as proof of the formation of only one
cycloadduct from this reaction, namely the meso form.
These chemical shift values are plotted against Hammett
sigma constants in Fig. 3.
In the case of electron-withdrawing groups in para
position of the phenyl ring, 3a-H/3a0-H protons were found
to resonate at more deshielded chemical shifts (Table 1).
Due to the molecular symmetry, only two doublets regarding
3a-H and 3a0-H protons and for 6a-H and 6a0-H protons were
observed in compounds 11, 12, and 13. This can be attrib-
uted to strong electron delocalization through the aromatic
ring due to the effect of the strong electron-withdrawing
The carbonyl carbons appeared at around 170–175 ppm
and azomethine carbons around 145–155 ppm depending
on the p-substituents in the 13C NMR spectra of the title
compounds.
123

964
Y. Du¨ru¨st, M. Yıldırım
In addition, a linear correlation between kmax values and
the Hammett substituent constants [61], rp, was obtained
for compounds 11, 12, and 13 (Figs. 7, 8, 9). To the best of
our knowledge, there are only two publications relating to
correlation of UV absorption frequencies with Hammett
substituent constants reported in the literature [62, 63].
Table 1 3a-H/3a’-H chemical shifts of 11a–11k
R
R
O
O
H
H
3a
6a
3a'
6a
N
N Ar
Experimental
N
N
'
N
N
1H and 13C NMR spectra were recorded on BRUKER and
VARIAN spectrometers (300 and 400 MHz for proton and
75 and 100 MHz for carbon). IR spectra were recorded on
a SHIMADZU FTIR-8400S instrument (KBr pellet).
Matrix-assisted laser desorption/ionization (MALDI) mass
spectra were run on a Bruker FTMS 4.7-T BioAPEX II
instrument, and also high-resolution mass spectra of the
compounds were measured on a Bruker FTMS 4.7-T
BioAPEX II and AEIMS 902 or a VG 7070E mass
spectrometer. Ultraviolet spectra were recorded in
1,2-dichloroethane on a Hitachi U-2900 spectrophotometer
at room temperature. Elemental analyses were performed
on a Eurovector EA 3000 instrument. Melting points were
determined on a MELTEMP apparatus. TLC was done
using precoated plates with fluorescent indicator (Merck
5735). Stain solutions of permanganate, p-anisaldehyde,
and iodine were used for visualization of TLC spots.
H
H
O
O
11
Ar= -Ph-CH2-Ph-
R
d3a-H (ppm)
a
b
c
d
e
f
H
5.30
5.30
5.34
5.22
5.29
5.46
5.47
5.20
5.22
5.40
5.25
Cl
Br
F
Me
CN
g
h
i
NO2
OMe
SMe
CF3
j
k
OCOMe
Preparation of 5,50-substituted bis(dihydropyrrolo
[3,4-c]pyrazoles) 11–13, typical procedure
Upon investigation of ultraviolet (UV) absorptions of
The corresponding hydrazonyl chloride 4 (0.5 mmol) and
bismaleimide 8, 9 or 10 (1 mmol) were dissolved in
20 cm3 dry acetonitrile. Et3N (0.404 g, 4 mmol) was added
dropwise to the mixture with stirring, and after complete
addition the reaction mixture was stirred at room temper-
ature for 2–4 h. Progress of the reaction was monitored by
TLC. After evaporating CH3CN, the reaction mixture was
compounds 11, 12, and 13 it was clearly found that elec-
tron-withdrawing groups (CF3, CN, and NO2) on the
phenyl ring attached to the azomethine carbon atom cause
kmax values (Table 2) to shift to longer wavelengths
(towards visible region), and electron-donating groups
(Me, OMe, SMe) to shorter wavelengths (Figs. 4, 5, 6).
Fig. 3 Correlation of the
chemical shifts of 3a-H versus
Hammett rp constants
of 11a–11k
6
5.9
5.8
5.7
5.6
5.5
5.4
5.3
5.2
5.1
5
R
R
y = 0.2451x + 5.2608
O
O
N
O
H
R2 = 0.7602
H
Ar
N
N
N
N
N
H
H
O
p-NO2
p-CN
Ar=-Ph-CH2-Ph-
p-CF3
p-Br
p-H
p-Cl
p-Me
p-OMe
p-OCOMe
p-F
p-SMe
0
-0.4
-0.2
0.2
0.4
0.6
0.8
1
1.2
123

Synthesis, UV–Vis spectra, and Hammett correlation
965
129.6, 129.5, 129.3, 128.6, 127.2, 126.4, 121.6, 114.5, 65.6
(–CH), 53.5 (–CH), 41.0 (–CH2–) ppm; HRMS: calculated
for C47H34N6O4 746.2985, found [M ? NH4]? 764.2991.
Table 2 UV absorption maxima (kmax) and e of compounds 11–13
Compound
Substituent
kmax (nm)
e/104
(dm3 mol-1 cm-1),
ClCH2CH2Cl
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Methylenebis(4,1-
phenylene)]bis[3-(4-chlorophenyl)-3a,6a-dihydro-1-
phenylpyrrolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
(11b, C47H32Cl2N6O4)
11a
11b
11c
11d
11e
11f
11g
11h
11i
p-H
350.0
357.0
358.0
348.5
349.0
378.5
419.0
349.5
362.0
364.5
353.5
350.0
357.5
358.0
349.0
383.0
418.5
349.0
365.0
353.0
349.0
357.0
358.5
348.5
378.5
417.0
349.0
364.0
353.0
3.36
3.72
3.45
3.00
3.77
3.65
3.37
3.23
3.44
2.93
3.48
3.06
3.35
3.44
3.40
3.49
3.20
3.24
3.44
3.42
3.25
3.12
3.11
3.45
4.13
3.10
3.22
3.09
3.01
p-Cl
p-Br
Yellow–grey crystalline solid; yield 190 mg (92%); m.p.:
p-F
194–196 °C; Rf = 0.70 (ethyl acetate–n-hexane 1:2); IR
p-Me
ꢀ
(KBr): m ¼ 3; 057 (arom. C–H), 1,720 (C=O), 1,599 (C=N),
p-CN
p-NO2
p-OMe
p-SMe
p-CF3
p-OCOMe
p-H
1,512, 1,492, 1,379, 1,193, 752, 690 cm-1
;
1H NMR
(400 MHz, CDCl3): d = 8.03 (d, J = 8.0 Hz, 4H), 7.62 (d,
J = 8.0 Hz, 4H), 7.40 (t, J = 8.1 Hz, 8H), 7.22 (s, 8H),
7.03 (t, J = 7.0 Hz, 2H), 5.30 (d, J = 10.9 Hz, 2H), 4.97
(d, J = 10.9 Hz, 2H), 4.00 (s, 2H) ppm; 13C NMR
(100 MHz, CDCl3): d = 171.7 (C=O), 170.9 (C=O),
144.8 (C=N), 142.0, 141.8, 135.5, 130.0, 129.7, 129.5,
129.4, 129.3, 128.7, 126.7, 121.8, 114.8, 65.8 (–CH), 53.0
(–CH), 41.0 (–CH2) ppm; MALDI-MS (pos. mode,
DCTB): m/z (%) = 814 (100) [M]?, 815 (51) [M ? H]?,
816 (70) [M ? 2]?, 817 (30) [M ? 3]?; HRMS: calculated
for C47H32Cl2N6O4 814.1862, found 814.1852.
11j
11k
12a
12b
12c
12e
12f
12g
12h
12j
12k
13a
13b
13c
13e
13f
13g
13h
13j
13k
p-Cl
p-Br
p-Me
p-CN
p-NO2
p-OMe
p-CF3
p-OCOMe
p–H
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Methylenebis(4,1-pheny-
lene)]bis[3-(4-bromophenyl)-3a,6a-dihydro-1-phenylpyr-
rolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
p-Cl
(11c, C47H32Br2N6O4)
Yellow crystalline solid; yield 230 mg (quant.); m.p.: 180–
p-Br
182 °C; Rf = 0.77 (ethyl acetate–n-hexane 1:2); IR (KBr):
p-Me
ꢀ
m ¼ 3; 057 (arom. C–H), 1,720 (C=O), 1,599 (C=N), 1,512,
p-CN
p-NO2
p-OMe
p-CF3
p-OCOMe
1
1,498, 1,375, 1,192, 750, 690 cm-1; H NMR (400 MHz,
CDCl3): d = 7.98 (d, J = 8.0 Hz, 4H), 7.64 (d, J = 9.0 Hz,
4H), 7.58 (d, J = 9.0 Hz, 4H), 7.38 (t, J = 7.4 Hz, 4H),
7.25–7.19 (q, J = 8.0 Hz, 8H), 7.04 (t, J = 12.3 Hz, 2H),
5.34 (d, J = 11.1 Hz, 2H), 5.01 (d, J = 11.0 Hz, 2H), 4.02
(s, 2H) ppm; 13C NMR (100 MHz, CDCl3): d = 171.4
(C=O), 170.6 (C=O), 151.5 (C=N), 144.2, 141.8, 141.3,
131.8, 129.8, 129.4, 129.3, 128.6, 126.3, 121.8, 114.6, 77.2,
65.7 (–CH), 53.4 (–CH), 41.0 (–CH2–) ppm; MALDI-MS
(pos. mode, DCTB): m/z (%) = 902 (50) [M]?, 904 (100)
[M ? 2]?, 906 (60) [M ? 4]?; HRMS: calculated for
C47H32Br2N6O4 902.0852, found 902.0849.
poured into 50 cm3 water to afford the crude crystalline
cycloadducts. The crystals were filtered and washed with
water (2 9 50 cm3) and hexane (2 9 25 cm3) and dried
thoroughly under vacuum to yield 11, 12 or 13.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Methylenebis(4,1-
phenylene)]bis(3a,6a-dihydro-1,3-diphenylpyrrolo-
[3,4-c]pyrazole-4,6(1H,5H)-dione) (11a, C47H34N6O4)
Yellow crystalline solid; yield 190 mg (quant.); m.p.: 278–
280 °C; Rf = 0.75 (ethyl acetate–n-hexane 1:2); IR (KBr):
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Methylenebis(4,1-
phenylene)]bis[3-(4-fluorophenyl)-3a,6a-dihydro-1-
phenylpyrrolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
(11d, C47H32F2N6O4)
ꢀ
m ¼ 3; 057 (arom. C–H), 1,720 (C=O), 1,597 (C=N), 1,511,
1
1,494, 1,379, 1,193, 752, 690 cm-1; H NMR (400 MHz,
Orange crystalline solid; yield 210 mg (quant.); m.p.: 183–
CDCl3): d = 8.05 (d, J = 8.0 Hz, 4H), 7.58 (d, J = 8.0 Hz,
4H), 7.51–7.32 (m, 18H), 7.03 (t, J = 7.2 Hz, 2H), 5.30 (d,
J = 11.0 Hz, 2H), 5.05 (d, J = 10.9 Hz, 2H), 4.01 (s,
2H) ppm; 13C NMR (100 MHz, CDCl3): d = 171.7 (C=O),
170.8 (C=O), 144.6 (C=N), 142.9, 141.2, 130.3, 129.7,
185 °C; Rf = 0.77 (ethyl acetate–n-hexane 1:2); IR (KBr):
ꢀ
m ¼ 3; 059 (arom. C–H), 1,724 (C=O), 1,597 (C=N), 1,512,
1,492, 1,381, 1,193, 839, 750, 690 cm-1
;
1H NMR
(400 MHz, CDCl3): d = 8.10–8.07 (q, J = 5.4, 2.3 Hz,
4H), 7.62 (d, J = 9.0 Hz, 4H), 7.37 (t, J = 7.5 Hz, 4H),
123

966
Y. Du¨ru¨st, M. Yıldırım
Fig. 4 UV–Vis spectra of
compounds 11a–11k
Fig. 5 UV-Vis spectra of
compounds 12a–12k
7.39–7.15 (m, 8H), 7.11 (t, J = 7.8 Hz, 4H), 7.03 (t, J =
6.8 Hz, 2H), 5.22 (d, J = 11.3 Hz, 2H), 4.92 (d, J =
10.9 Hz, 2H), 3.99 (s, 2H) ppm; 13C NMR (100 MHz,
CDCl3): d = 171.7 (C=O), 170.8 (C=O), 165.0 (C=N),
162.5, 144.5, 142.0, 141.3, 133.9, 129.8, 129.2, 129.0,
126.4, 121.7, 115.7, 114.5, 65.7(–CH), 53.6 (–CH), 41.0
(–CH2–) ppm; MALDI-MS (pos. mode, DCTB): m/z
(%) = 782 (100) [M]?, 783 (55) [M ? H]?; HRMS:
calculated for C47H32F2N6O4 782.2453, found 782.2441.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Methylenebis(4,1-
phenylene)]bis[3a,6a-dihydro-3-(4-methylphenyl)-1-
phenylpyrrolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
(11e, C49H38N6O4)
Yellow crystalline solid; yield 198 mg (quant.); m.p.: 180–
182 °C; Rf = 0.75 (ethyl acetate–n-hexane 1:2); IR (KBr):
ꢀm ¼ 3; 034 (arom. C–H), 1,720 (C=O), 1,597 (C=N), 1,514,
1,498, 1,379, 1,184, 817, 752, 692 cm-1
;
1H NMR
(400 MHz, CDCl3): d = 8.00 (d, J = 8.1 Hz, 4H), 7.64
123

Synthesis, UV–Vis spectra, and Hammett correlation
967
Fig. 6 UV–Vis spectra of
compounds 13a–13k
Fig. 7 Correlation between
Hammett rp constants and kmax
(nm) of 11a–11k
440
420
400
380
360
340
320
300
R
N
R
p-NO2
O
N
O
H
H
H
N
N Ar
N
N
H
O
O
Ar=ꢀPhꢀCH2ꢀPhꢀ
p-CN
p-Cl
p-Br
p-H
p-CF3
p-SMe
p-F
λ
p-OMe
p-Me
p-OCOMe
y = 48.234x + 353.28
R 2= 0.6202
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
1.2
σ
R
N
Fig. 8 Correlation between
Hammett rp constants and kmax
(nm) of 12a–12k
R
440
420
400
380
360
340
320
300
O
O
H
H
H
p-NO2
N
N
N Ar
N
N
H
O
O
Ar=ꢀPhꢀOꢀPhꢀ
p-CN
p-Cl
p-Br
p-CF3
p-Me
p-OMe
λ
p-OCOMe
p-H
y = 51.757x + 351.58
2 = 0.6725
R
-0.4 -0.3 -0.2 -0.1
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2
σp
123

968
Y. Du¨ru¨st, M. Yıldırım
R
N
Fig. 9 Correlation between
Hammett rp constants and kmax
(nm) of 13a–13k
440
420
400
380
360
340
320
300
R
O
N
O
H
H
H
N
N Ar
N
N
H
O
O
Ar=ꢀPhꢀ
λ
-0.4 -0.3 -0.2 -0.1
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
1.0 1.1 1.2
σp
(d, J = 7.8 Hz, 4H), 7.37 (t, J = 7.4 Hz, 6H), 7.28–7.20
(m, 10H), 7.02 (t, J = 7.3 Hz, 2H), 5.29 (d, J = 11.0 Hz,
2H), 5.03 (d, J = 10.9 Hz, 2H), 4.02 (s, 2H), 2.42 (s,
6H) ppm; 13C NMR (100 MHz, CDCl3): d = 171.8
(C=O), 170.8 (C=O), 144.8 (C=N), 143.1, 141.2, 139.8,
129.7, 129.5, 129.3, 129.2, 127.5, 127.2, 126.4, 121.4,
114.5, 65.6 (–CH), 53.6 (–CH), 41.0 (–CH2–), 21.5
8H), 7.67 (d, J = 9.0 Hz, 4H), 7.41 (t, J = 7.5 Hz, 4H),
7.27–7.20 (m, 8H), 7.09 (t, J = 7.3 Hz, 2H), 5.47 (d, J =
11.2 Hz, 2H), 5.08 (d, J = 11.2 Hz, 2H), 4.03 (s, 2H) ppm;
13C NMR (100 MHz, CDCl3): d = 170.9 (C=O), 170.5
(C=O), 147.7 (C=N), 143.3, 141.4, 140.2, 136.5, 129.8,
129.7, 129.4, 127.5, 126.3, 123.9, 122.6, 114.8, 65.7
(–CH), 53.0 (–CH), 45.7(–CH2–) ppm; MALDI-MS (pos.
mode, DCTB): m/z (%) = 836 (100) [M]?, 837 (70)
[M ? H]?; HRMS: calculated for C47H32N8O8 836.2343,
found 836.2338.
?
(–CH3) ppm; HRMS: calculated for C49H38N6O4 ? NH4
792.3298, found 792.3296.
(3aR*,6aR*,3a0S*,6a0S*)-4,40-[Methylenebis[(4,1-pheny-
lene)(3a,4,6,6a-tetrahydro-4,6-dioxo-1-phenylpyrrolo-
[3,4-c]pyrazole-5,3(1H)-diyl)]]bis[benzonitrile]
(11f, C49H32N8O4)
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Methylenebis(4,1-pheny-
lene)]bis[3a,6a-dihydro-3-(4-methoxyphenyl)-1-phenylpyr-
rolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
Bright-yellow crystalline solid; yield 203 mg (quant.); m.p.:
(11h, C49H38N6O6)
Brown crystalline solid; yield 215 mg (quant.); m.p.: 169–
209–211 °C; Rf = 0.6 (ethyl acetate–n-hexane 1:2); IR
ꢀ
(KBr): m ¼ 3; 059 (arom. C–H), 2,225 (C:N), 1,720 (C=O),
171 °C; Rf = 0.37 (ethyl acetate–n-hexane 1:2); IR (KBr):
ꢀ
1,597 (C=N), 1,512, 1,498, 1,381, 1,193, 842, 752,
692 cm-1; 1H NMR (400 MHz, CDCl3): d = 8.20 (d, J =
8.4 Hz, 4H), 7.73 (d, J = 8.5 Hz, 4H), 7.66 (d, J = 8.5 Hz,
4H), 7.40 (t, J = 7.3 Hz, 4H), 7.32–7.17 (m, 8H), 7.08 (t,
J = 7.3 Hz, 2H), 5.46 (d, J = 11.2 Hz, 2H), 5.06 (d,
J = 11.2 Hz, 2H), 4.04 (s, 2H) ppm; 13C NMR
(100 MHz, CDCl3): d = 171.2 (C=O), 170.6 (C=O), 143.5
(C=N), 141.4, 140.7, 134.7, 132.3, 129.8, 129.4, 129.3,
127.3, 126.3, 122.4, 118.8, 114.7, 112.2 (C:N), 65.7
(–CH), 53.1 (–CH), 41.0 (–CH2–) ppm; HRMS: calculated
for C49H32N8O4 ? NH4? 814.2890, found 814.2894.
m ¼ 3; 057 (arom. C–H), 1,720 (C=O), 1,597 (C=N), 1,512,
1
1,498, 1,379, 1,253, 1,176, 835, 750, 692 cm-1; H NMR
(400 MHz, CDCl3): d = 8.05 (d, J = 8.8 Hz, 4H), 7.61 (d,
J = 7.7 Hz, 4H), 7.36 (t, J = 7.4 Hz, 4H), 7.28–6.70 (m,
14H), 5.20 (d, J = 10.9 Hz, 2H), 4.93 (d, J = 10.9 Hz,
2H), 4.02 (s, 2H), 3.86 (s, 6H) ppm; 13C NMR (100 MHz,
CDCl3): d = 171.9 (C=O), 170.9 (C=O), 160.8 (C=N),
145.0, 142.9, 141.2, 134.1, 129.7, 129.2, 128.9, 126.4,
123.0, 121.3, 114.4, 114.0, 65.7 (–CH), 55.4 (–O–CH3),
53.7 (–CH), 41.0 (–CH2–) ppm; MALDI-MS (pos. mode,
DCTB): m/z (%) = 806 (100) [M]?, 807 (55) [M ? H]?;
HRMS: calculated for C49H38N6O6 806.2853, found
806.2848.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Methylenebis(4,1-pheny-
lene)]bis[3a,6a-dihydro-3-(4-nitrophenyl)-1-phenylpyrrolo-
[3,4-c]pyrazole-4,6(1H,5H)-dione] (11g, C47H32N8O8)
Dark-orange crystalline solid; yield 215 mg (quant.); m.p.:
208–210 °C; Rf = 0.5 (ethyl acetate–n-hexane 1:2); IR
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Methylenebis(4,1-pheny-
lene)]bis[3a,6a-dihydro-3-[4-(methylthio)phenyl]-1-
phenylpyrrolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
(11i, C49H38N6O4S2)
ꢀ
(KBr): m ¼ 3; 041 (arom. C–H), 1,720 (C=O), 1,595 (C=N),
1
1,546, 1,512, 1,500, 1,381, 1,193, 850, 750, 690 cm-1; H
Brown crystalline solid; yield 224 mg (quant.); m.p.: 170–
172 °C; Rf = 0.50 (ethyl acetate–n-hexane 1:2); IR (KBr):
NMR (400 MHz, CDCl3): d = 8.33–8.20 (q, J = 9.0 Hz,
123

Synthesis, UV–Vis spectra, and Hammett correlation
969
ꢀm ¼ 3; 036 (arom. C–H), 1,720 (C=O), 1,597 (C=N), 1,510,
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Oxybis(4,1-pheny-
lene)]bis(3a,6a-dihydro-1,3-diphenylpyrrolo[3,4-c]-
pyrazole-4,6(1H,5H)-dione) (12a, C46H32N6O5)
1,492, 1,379, 1,188, 821, 750, 690 cm-1
;
1H NMR
(400 MHz, CDCl3): d = 7.98 (d, J = 8.3 Hz, 4H), 7.62
(d, J = 8.1 Hz, 4H), 7.36 (t, J = 7.6 Hz, 4H), 7.30–7.10
(m, 12H), 7.03 (t, J = 7.2 Hz, 2H), 5.22 (d, J = 10.9 Hz,
2H), 4.91 (d, J = 10.9 Hz, 2H), 3.97 (s, 2H), 2.50 (s,
6H) ppm; 13C NMR (100 MHz, CDCl3): d = 171.7
(C=O), 170.8 (C=O), 144.6 (C=N), 142.6, 141.2, 140.8,
129.7, 129.5, 129.2, 127.5, 126.9, 126.4, 125.9, 121.5,
114.5, 65.6 (–CH), 53.5 (–CH), 41.0 (–CH2–), 15.3 (–S–
CH3) ppm; MALDI-MS (pos. mode, DCTB): m/z
(%) = 838 (100) [M]?, 839 (56) [M ? H]?; HRMS:
calculated for C49H38N6O4S2 838.2396, found 838.2397.
Yellow–green crystalline solid; yield 177 mg (95%); m.p.:
178–180 °C (dec.); Rf = 0.47 (ethyl acetate–n-hexane 1:2);
ꢀ
IR (KBr): m ¼ 3; 061 (arom. C–H), 1,720 (C=O), 1,597
(C=N), 1,500, 1,383, 1,244, 1,193, 754, 690 cm-1; 1H NMR
(400 MHz, CDCl3): d = 7.89 (d, J = 7.9 Hz, 4H), 7.42 (d,
J = 8.2 Hz, 4H), 7.30–7.05 (m, 14H), 6.88 (d, J = 8.0 Hz,
4H), 6.78 (t, J = 7.0 Hz, 2H), 5.22 (d, J = 10.8 Hz, 2H),
4.98 (d, J = 10.8 Hz, 2H) ppm; 13C NMR (100 MHz,
CDCl3): d = 173.1 (C=O), 172.1 (C=O), 156.7 (C=N),
145.0, 144.5, 131.0, 129.7, 129.5, 129.4, 128.9, 127.8,
127.5, 121.2, 119.6, 114.4, 66.3 (–CH), 54.5 (–CH) ppm;
MALDI-MS (pos. mode, DCTB): m/z (%) = 748 (100)
[M]?, 749 (50) [M ? H]?; HRMS: calculated for
C46H32N6O5 748.2434, found 748.2430.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Methylenebis(4,1-pheny-
lene)]bis[3a,6a-dihydro-1-phenyl-3-[4-(trifluoro-
methyl)phenyl]pyrrolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
(11j, C49H32F6N6O4)
Bright-yellow crystalline solid; yield 223 mg (quant.);
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Oxybis(4,1-pheny-
lene)]bis[3-(4-chlorophenyl)-3a,6a-dihydro-1-
phenylpyrrolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
(12b, C46H30Cl2N6O5)
m.p.: 185–187 °C; Rf = 0.45 (ethyl acetate–n-hexane 1:2);
ꢀ
IR (KBr): m ¼ 3; 059 (arom. C–H), 1,720 (C=O), 1,599
(C=N), 1,550, 1,517, 1,498, 1,383, 1,166, 1,124, 844, 752,
692 cm-1
;
1H NMR (400 MHz, CDCl3 ? DMSO-d6):
Olive-green crystalline solid; yield 206 mg (quant.); m.p.:
d = 8.16 (d, J = 8.1 Hz, 4H), 7.65–7.59 (dd, J = 8.3,
7.9 Hz, 8H), 7.33 (t, J = 7.5 Hz, 4H), 7.18 (dd, J = 8.6,
4.2 Hz, 8H), 6.99 (t, J = 7.3 Hz, 2H), 5.40 (d,
J = 11.1 Hz, 2H), 5.06 (d, J = 11.1 Hz, 2H), 3.98 (s,
2H) ppm; 13C NMR (100 MHz, CDCl3 ? DMSO-d6):
d = 176.8 (C=O), 176.0 (C=O), 149.0 (C=N), 146.8,
146.0, 139.0, 134.6, 134.2, 134.0, 132.0, 131.5, 130.2,
129.8, 126.4, 119.5, 119.3, 71.0 (–CH), 58.5, (–CH), 50.8
(–CH2–) ppm; HRMS: calculated for C49H32F6N6O4 ?
167–169 °C (dec.); Rf = 0.56 (ethyl acetate–n-hexane 1:2);
ꢀ
IR (KBr): m ¼ 3; 061 (arom. C–H), 1,720 (C=O), 1,599
(C=N), 1,500, 1,381, 1,242, 1,193, 831, 750, 692 cm-1; 1H
NMR (400 MHz, CDCl3): d = 8.04 (d, J = 8.1 Hz, 4H),
7.54 (t, J = 8.6 Hz, 8H), 7.35 (d, J = 7.9 Hz, 8H), 7.14 (d,
J = 8.3 Hz, 4H), 6.96 (t, J = 7.0 Hz, 2H), 5.55 (d,
J = 10.9 Hz, 2H), 5.36 (d, J = 10.8 Hz, 2H) ppm; 13C
NMR (100 MHz, CDCl3): d = 173.0 (C=O), 172.1 (C=O),
156.7 (C=N), 144.7, 143.4, 134.3, 129.9, 129.5, 129.4,
129.0, 127.8, 121.3, 119.6, 114.5, 66.4 (–CH), 54.4
(–CH) ppm; MALDI-MS (pos. mode, DCTB): m/z
(%) = 816 (100) [M]?, 818 (70) [M ? 2]?, 819 (40)
[M ? 3]?; HRMS: calculated for C46H30Cl2N6O5
816.1655, found 816.1649.
?
NH4 900.22733, found 900.2736.
(3aR*,6aR*,3a0S*,6a0S*)-4,40-[Methylenebis[(4,1-pheny-
lene)(3a,4,6,6a-tetrahydro-4,6-dioxo-1-phenylpyrrolo-
[3,4-c]pyrazole-5,3(1H)-diyl)]]bis[phenyl acetate]
(11k, C51H38N6O8)
Light-yellow crystalline solid; yield 203 mg (95%); m.p.:
ꢀ
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Oxybis(4,1-pheny-
lene)]bis[3-(4-bromophenyl)-3a,6a-dihydro-1-phe-
nylpyrrolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
(12c, C46H30Br2N6O5)
190–192 °C; Rf = 0.75 (ethyl acetate); IR (KBr): m ¼
3; 061 (arom. C–H), 1,720 (C=O), 1,599 (C=N), 1,510,
1
1,498, 1,371, 1,199, 1,166, 848, 752, 692 cm-1; H NMR
(400 MHz, CDCl3): d = 8.10 (d, J = 8.4 Hz, 4H), 7.62 (d,
J = 7.9 Hz, 4H), 7.35 (t, J = 7.3 Hz, 4H), 7.23–7.10 (m,
12H), 7.05 (t, J = 7.0 Hz, 2H), 5.25 (d, J = 11.0 Hz, 2H),
4.90 (d, J = 10.9 Hz, 2H), 4.00 (s, 2H), 2.34 (s, 6H) ppm;
13C NMR (100 MHz, CDCl3): d = 171.7 (C=O), 170.8
(C=O), 169.3 (C=O), 151.5 (C=N), 144.5, 142.0, 141.3,
129.7, 129.5, 129.2, 128.4, 128.2, 126.4, 121.8, 121.6,
114.5, 65.8 (–CH), 53.5 (–CH), 41.0 (–CH2–), 21.2
Light-brown crystalline solid; yield 226 mg (quant.); m.p.:
174–176 °C (dec.); Rf = 0.63 (ethyl acetate–n-hexane 1:2);
ꢀ
IR (KBr): m ¼ 3; 045 (arom. C–H), 1,720 (C=O), 1,599
(C=N), 1,500, 1,381, 1,244, 1,193, 829, 750, 692 cm-1; 1H
NMR (400 MHz, CDCl3): d = 7.96 (d, J = 8.4 Hz, 4H),
7.68 (d, J = 8.4 Hz, 4H), 7.52 (d, J = 8.3 Hz, 4H), 7.31 (t,
J = 8.1 Hz, 8H), 7.10 (d, J = 8.7 Hz, 4H), 6.92 (t,
J = 7.3 Hz, 2H), 5.55 (d, J = 11.0 Hz, 2H), 5.35 (d,
J = 10.9 Hz, 2H) ppm; 13C NMR (100 MHz, CDCl3):
d = 173.1 (C=O), 172.1 (C=O), 156.7 (C=N), 145.0,
?
(–CH3) ppm; HRMS: calculated for C51H38N6O8 ? NH4
880.3095, found 880.3094.
123

970
Y. Du¨ru¨st, M. Yıldırım
143.5, 132.1, 130.5, 129.7, 129.5, 129.4, 127.8, 123.5,
121.5, 119.6, 114.5, 66.4 (–CH), 54.5 (–CH) ppm; MALDI-
MS (pos. mode, DCTB): m/z (%) = 904 (50) [M]?, 906
(100) [M ? 2]?, 907 (50) [M ? 3]?, 908 (50) [M ? 4]?;
HRMS: calculated for C46H30Br2N6O5 904.0644, found
904.0635.
ane 1:2); IR (KBr): ꢀm ¼ 3; 109; 3; 057 (arom. C–H), 1,720
(C=O), 1,595 (C=N), 1,546, 1,498, 1,383, 1,340, 1,242,
1
1,193, 835, 750, 688 cm-1; H NMR (400 MHz, CDCl3):
d = 8.32 (d, J = 8.9 Hz, 4H), 8.22 (d, J = 8.9 Hz, 4H),
7.58 (d, J = 7.9 Hz, 4H), 7.40–7.30 (q, J = 7.50 Hz, 8H),
7.14 (d, J = 8.8 Hz, 4H), 7.00 (t, J = 7.2 Hz, 2H), 5.68 (d,
J = 11.1 Hz, 2H), 5.42 (d, J = 11.1 Hz, 2H) ppm; 13C
NMR (100 MHz, CDCl3): d = 172.7 (C=O), 172.0 (C=O),
156.7 (C=N), 147.5, 143.9, 142.3, 137.5, 129.6, 129.5,
128.1, 127.8, 124.2, 121.9, 119.5, 114.8, 66.5 (–CH), 54.0
(–CH) ppm; MALDI-MS (pos. mode, DCTB): m/z (%) =
838 (100) [M]?, 839 (55) [M ? H]?; HRMS: calculated
for C46H30N8O9 838.2136, found 838.2133.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Oxybis(4,1-pheny-
lene)]bis[3a,6a-dihydro-3-(4-methylphenyl)-1-phenylpyr-
rolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
(12e, C48H36N6O5)
Bright-yellow powder; yield 188 mg (97%); m.p.: 173–
175 °C (dec.); Rf = 0.56 (ethyl acetate–n-hexane 1:2); IR
ꢀ
(KBr): m ¼ 3; 066 (arom. C–H), 2,918 (aliph. C–H), 1,720
(C=O), 1,597 (C=N), 1,500, 1,381, 1,244, 1,194, 819, 750,
692 cm-1 1H NMR (400 MHz, CDCl3): d = 7.90 (d,
;
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Oxybis(4,1-pheny-
lene)]bis[3a,6a-dihydro-3-(4-methoxyphenyl)-1-
phenylpyrrolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
(12h, C48H36N6O7)
J = 7.8 Hz, 4H), 7.50 (d, J = 8.0 Hz, 4H), 7.40–7.20 (m,
12H), 7.14 (d, J = 8.5 Hz, 4H), 6.91 (t, J = 7.1 Hz, 2H),
5.50 (d, J = 10.8 Hz, 2H), 5.34 (d, J = 10.8 Hz, 2H), 2.42
(s, 6H) ppm; 13C NMR (100 MHz, CDCl3): d = 173.2
(C=O), 172.1 (C=O), 156.7 (C=N), 145.2, 144.6, 139.5,
129.5, 129.5, 129.4, 128.3, 127.9, 127.5, 121.0, 119.6,
114.4, 66.3 (–CH), 54.6 (–CH), 21.4 (–CH3) ppm; MALDI-
MS (pos. mode, DCTB): m/z (%) = 776 (100) [M]?, 777
(55) [M ? H]?; HRMS: calculated for C48H36N6O5
776.2747, found 776.2746.
Light-orange–brown crystalline solid; yield 202 mg
(quant.); m.p.: 164–166 °C (dec.); Rf = 0.60 (ethyl ace-
ꢀ
tate–n-hexane 1:3); IR (KBr): m ¼ 3; 057 (arom. C–H),
1,720 (C=O), 1,597 (C=N), 1,498, 1,381, 1,247, 1,176, 833,
750, 692 cm-1; 1H NMR (300 MHz, CDCl3): d = 8.02 (d,
J = 8.7 Hz, 4H), 7.58 (t, J = 7.9 Hz, 4H), 7.30 (t, J =
7.9 Hz, 4H), 7.25–6.62 (m, 14H), 5.22 (d, J = 10.8 Hz,
2H), 4.96 (d, J = 10.8 Hz, 2H), 3.83 (s, 6H) ppm; 13C
NMR (100 MHz, CDCl3): d = 172.1 (C=O), 171.1 (C=O),
161.0 (C=N), 156.9, 145.1, 143.1, 129.4, 129.0, 128.7,
128.2, 123.1, 121.6, 119.7, 114.6, 114.2, 65.8 (–CH), 55.6
(O–CH3), 53.8 (–CH) ppm. Anal Calcd for C48H36N6O7.
C, 71.28; H, 4.49; N, 10.39; found C, 70.70; H, 4.69; N,
10.43.
(3aR*,6aR*,3a0S*,6a0S*)-4,40-[Oxybis[(4,1-pheny-
lene)(3a,4,6,6a-tetrahydro-4,6-dioxo-1-phenylpyrrolo-
[3,4-c]pyrazole-5,3(1H)-diyl)]]bis[benzonitrile]
(12f, C48H30N8O5)
Bright-yellow crystalline solid; yield 190 mg (95%); m.p.:
288–290 °C (dec.); Rf = 0.25 (ethyl acetate–n-hexane 1:2);
ꢀ
IR (KBr): m ¼ 3; 057 (arom. C–H), 2,225 (C:N), 1,722
(C=O), 1,599 (C=N), 1,500, 1,383, 1,242, 1,193, 839, 750,
692 cm-1; 1H NMR (400 MHz, CDCl3): d = 8.11 (d, J =
8.4 Hz, 4H), 7.61 (d, J = 8.3 Hz, 4H), 7.52 (d, J = 7.9 Hz,
4H), 7.40 (d, J = 12.8 Hz, 2H), 7.25 (t, J = 7.5 Hz, 2H),
7.20 (d, J = 8.8 Hz, 4H), 7.01 (d, J = 8.9 Hz, 4H), 6.90 (t,
J = 7.1 Hz, 2H), 5.45 (d, J = 11.1 Hz, 2H), 5.10 (d,
J = 11.1 Hz, 2H) ppm; 13C NMR (100 MHz, CDCl3):
d = 172.6 (C=O), 171.9 (C=O), 156.7 (C=N), 144.1,
142.4, 135.5, 132.6, 129.4, 129.4, 129.2, 127.8, 121.7,
119.5, 119.1, 114.7, 111.4 (C:N), 66.4 (–CH), 53.9
(–CH) ppm; MALDI-MS (pos. mode, DCTB): m/z
(%) = 798 (90) [M]?, 799 (50) [M ? H]?; HRMS: calcu-
lated for C48H30N8O5 798.2339, found 798.2334.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Oxybis(4,1-pheny-
lene)]bis[3a,6a-dihydro-1-phenyl-3-[4-(trifluoro-
methyl)phenyl]pyrrolo[3,4-c]pyrazole-4,6(1H,5H)-dione]
(12j, C48H30F6N6O5)
Bright-yellow crystalline solid; yield 213 mg (96%); m.p.:
184–186 °C (dec.); Rf = 0.62 (ethyl acetate–n-hexane
ꢀ
1:3); IR (KBr): m ¼ 3; 059 (arom. C–H), 1,724 (C=O),
1,599 (C=N), 1,500, 1,384, 1,244, 750, 692 cm-1
;
1H
NMR (300 MHz, CDCl3): d = 8.20 (d, J = 8.2 Hz, 4H),
7.69–7.62 (dd, J = 14.9, 8.4 Hz, 8H), 7.38 (t,
J = 7.6 Hz, 4H), 7.27–7.25 (m, 4H), 7.09–7.02 (m, 6H),
5.40 (d, J = 11.1 Hz, 2H), 5.07 (d, J = 11.1 Hz,
2H) ppm; 13C NMR (100 MHz, CDCl3): d = 171.5
(C=O), 170.8 (C=O), 157.0 (C=N), 144.0, 141.3, 133.8,
129.5, 128.1, 128.0, 127.4, 126.6, 125.8, 125.7, 122.4,
119.7, 114.8, 65.8 (–CH), 53.4 (–CH) ppm. Anal Calcd
for C48H30F6N6O5. C, 65.16; H, 3.42; N, 9.50; found C,
65.30; H, 3.73; N, 9.63.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-[Oxybis(4,1-pheny-
lene)]bis[3a,6a-dihydro-3-(4-nitrophenyl)-1-phenylpyrrolo-
[3,4-c]pyrazole-4,6(1H,5H)-dione] (12g, C46H30N8O9)
Dark-orange crystalline solid; yield 209.5 mg (quant.);
m.p.: 208–210 °C (dec.); Rf = 0.29 (ethyl acetate–n-hex-
123

Synthesis, UV–Vis spectra, and Hammett correlation
971
(3aR*,6aR*,3a0S*,6a0S*)-4,40-[Oxybis[(4,1-pheny-
lene)(3a,4,6,6a-tetrahydro-4,6-dioxo-1-phenylpyrrolo-
[3,4-c]pyrazole-5,3(1H)-diyl)]]bis[phenyl acetate]
(12k, C50H36N6O9)
[M ? 3]?; HRMS: calculated for C40H26Cl2N6O4
724.1393, found 724.1388.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-(1,4-Phenylene)bis[3-
(4-bromophenyl)-3a,6a-dihydro-1-phenylpyrrolo[3,4-
c]pyrazole-4,6(1H,5H)-dione] (13c, C40H26Br2N6O4)
Light-brown crystalline solid; yield 182 mg (90%); m.p.:
263–265 °C (dec.); Rf = 0.50 (ethyl acetate–n-hexane
Brown crystalline solid; yield 220 mg (quant.); m.p.: 190–
192 °C (dec.); Rf = 0.25 (ethyl acetate–n-hexane 1:3); IR
(KBr): ꢀm ¼ 3; 066 (arom. C–H), 1,720 (C=O), 1,599 (C=N),
1
1,500, 1,371, 1,197, 750, 690 cm-1; H NMR (300 MHz,
ꢀ
1:2); IR (KBr): m ¼ 3; 043 (arom. C–H), 1,722 (C=O),
CDCl3): d = 8.10 (d, J = 8.7 Hz, 4H), 7.60 (d,
J = 8.7 Hz, 4H), 7.38 (t, J = 7.3 Hz, 4H), 7.23–6.85 (m,
14H), 5.26 (d, J = 11.1 Hz, 2H), 4.95 (d, J = 10.8 Hz,
2H), 2.30 (s, 6H) ppm; 13C NMR (100 MHz, CDCl3):
d = 171.9 (C=O), 171.0 (C=O), 169.5 (C=O), 151.8
(C=N), 144.6, 142.1, 129.5, 128.6, 128.3, 128.2, 126.7,
122.1, 121.9, 119.7, 114.7, 65.9 (–CH), 53.7 (–CH), 21.4
(COCH3) ppm. Anal Calcd for C50H36N6O9. C, 69.44; H,
4.20; N, 9.72; found C, 69.39; H, 4.48; N, 9.77.
1,599 (C=N), 1,512, 1,492, 1,365, 1,294, 1,176, 827, 750,
1
690 cm-1; H NMR (400 MHz, DMSO-d6): d = 7.85 (d,
J = 8.5 Hz, 4H), 7.54–7.39 (m, 10H), 7.28–7.2.0 (m, 4H),
6.93 (t, J = 7.2 Hz, 4H), 5.26 (d, J = 11.1 Hz, 2H), 4.94
(d, J = 11.0 Hz, 2H) ppm; 13C NMR (100 MHz, DMSO-
d6): d = 172.9 (C=O), 171.9 (C=O), 144.3 (C=N), 142.0,
131.8, 131.5, 129.3, 129.2, 128.5, 126.8, 123.7, 121.8,
114.5, 65.8 (–CH), 53.5 (–CH) ppm; MALDI-MS (pos.
mode, DCTB): m/z (%) = 812 (50) [M]?, 814 (100)
[M ? 2]?, 816 (50) [M ? 4]?; HRMS: calculated for
C40H26Br2N6O4 812.0382, found 812.0379.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-(1,4-Phenylene)bis(3a,6a-
dihydro-1,3-diphenylpyrrolo[3,4-c]pyrazole-4,6(1H,5H)-
dione) (13a, C40H28N6O4)
(3aR*,6aR*,3a0S*,6a0S*)-5,50-(1,4-Phenylene)bis[3a,6a-
dihydro-3-(4-methylphenyl)-1-phenylpyrrolo[3,4-c]-
pyrazole-4,6(1H,5H)-dione] (13e, C42H32N6O4)
Light-yellow powder; yield 158 mg (96%); m.p.: 354–
356 °C (dec.); Rf = 0.62 (ethyl acetate–n-hexane 1:2); IR
ꢀ
(KBr): m ¼ 3; 057 (arom. C–H), 1,722 (C=O), 1,597
Creamy-white powder; yield 165 mg (96%); m.p.: 338–
(C=N), 1,517, 1,498, 1,371, 1,290, 1,195, 758,
684 cm-1 1H NMR (400 MHz, DMSO-d6): d = 8.02
;
340 °C (dec.); Rf = 0.69 (ethyl acetate–n-hexane 1:2); IR
ꢀ
(KBr): m ¼ 3; 066 (arom. C–H), 2941 (aliph. C–H), 1,724
(d, J = 7.4 Hz, 4H), 7.52 (d, J = 8.0 Hz, 6H), 7.49–7.38
(m, 8H), 7.33 (t, J = 7.7 Hz, 4H), 6.94 (t, J = 7.0 Hz,
2H), 5.52 (d, J = 10.9 Hz, 2H), 5.35 (d, J = 10.8 Hz,
2H) ppm; 13C NMR (100 MHz, DMSO-d6): d = 172.9
(C=O), 171.9 (C=O), 144.9 (C=N), 144.2, 132.4, 130.9,
129.7, 129.4, 128.8, 128.1, 127.9, 127.5,121.1, 114.4, 66.3
(–CH), 54.5 (–CH) ppm; MALDI-MS (pos. mode,
DCTB): m/z (%) = 656 (100) [M]?, 657 (45)
[M ? H]?; HRMS: calculated for C40H28N6O4
656.2172, found 656.2162.
(C=O), 1,595 (C=N), 1,514, 1,498, 1,371, 1,288, 1,195,
819, 754, 692 cm-1 1H NMR (400 MHz, DMSO-d6):
;
d = 7.86 (d, J = 8.1 Hz, 4H), 7.49 (d, J = 7.9 Hz, 4H),
7.42 (s, 4H), 7.24 (t, J = 7.5 Hz, 4H), 7.15 (d, J = 8.1 Hz,
4H), 6.88 (t, J = 7.2 Hz, 2H), 5.30 (d, J = 10.9 Hz, 2H),
5.06 (d, J = 10.9 Hz, 2H), 2.30 (s, 6H) ppm; 13C NMR
(100 MHz, DMSO-d6): d = 173.0 (C=O), 171.9 (C=O),
145.1 (C=N), 144.5, 139.5, 132.5, 129.6, 129.5, 129.4,
128.2, 127.5, 121.0, 114.3, 66.3 (–CH), 54.6 (–CH), 21.4
(–CH3) ppm; MALDI-MS (pos. mode, DCTB): m/z
(%) = 684 (100) [M]?, 685 (50) [M ? H]?; HRMS:
calculated for C42H32N6O4 684.2485, found 684.2478.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-(1,4-Phenylene)bis[3-
(4-chlorophenyl)-3a,6a-dihydro-1-phenylpyrrolo-
[3,4-c]pyrazole-4,6(1H,5H)-dione]
(3aR*,6aR*,3a0S*,6a0S*)-4,40-[(4,1-Pheny-
lene)bis(3a,4,6,6a-tetrahydro-4,6-dioxo-1-phenylpyrrolo-
[3,4-c]pyrazole-5,3(1H)-diyl)]bis[benzonitrile]
(13f, C42H26N8O4)
(13b, C40H26Cl2N6O4)
Light-green crystalline solid; yield 177 mg (98%); m.p.:
205–207 °C (dec.); Rf = 0.63 (ethyl acetate–n-hexane
Yellow powder; yield 168 mg (95%); m.p.: 361–363 °C
(dec.); Rf = 0.37 (ethyl acetate–n-hexane 1:2); IR (KBr):
ꢀ
1:2); IR (KBr): m ¼ 3; 064 (arom. C–H), 1,722 (C=O),
1,597 (C=N), 1,514, 1,492, 1,367, 1,292, 1,190, 831, 752,
1
692 cm-1; H NMR (400 MHz, DMSO-d6): d = 8.04 (d,
ꢀ
m ¼ 3; 063 (arom. C–H), 2,225 (C:N), 1,724 (C=O),
1,597 (C=N), 1,514, 1,498, 1,367, 1,255, 1,190, 837, 754,
1
J = 6.5 Hz, 4H), 7.84–7.13 (m, 16H), 6.97 (s, 2H), 5.57 (d,
J = 10.1 Hz, 2H), 5.38 (d, J = 10.2 Hz, 2H) ppm; 13C
NMR (100 MHz, DMSO-d6): d = 172.9 (C=O), 171.9
(C=O), 144.7 (C=N), 143.3, 134.3, 132.5, 129.9, 129.5,
129.1, 129.0, 128.2, 126.4, 121.3, 114.4, 66.4 (–CH), 54.5
(–CH) ppm; MALDI-MS (pos. mode, DCTB): m/z
(%) = 724 (100) [M]?, 726 (80) [M ? 2]?, 727 (35)
690 cm-1; H NMR (400 MHz, DMSO-d6): d = 8.02 (d,
J = 8.3 Hz, 4H), 7.77 (d, J = 8.2 Hz, 4H), 7.40 (d, J =
7.8 Hz, 4H), 7.23 (t, J = 7.4 Hz, 4H), 6.86 (t, J = 7.1 Hz,
2H), 5.51 (d, J = 11.4 Hz, 2H), 5.22 (d, J = 10.9 Hz,
2H) ppm; 13C NMR (100 MHz, DMSO-d6): d = 172.9
(C=O), 171.9 (C=O), 144.7 (C=N), 143.3, 134.3, 132.5,
123

972
Y. Du¨ru¨st, M. Yıldırım
129.9, 129.5, 129.1, 129.0, 128.2, 126.4, 121.3, 114.4
(C:N), 66.4 (–CH), 54.5 (–CH) ppm; MALDI-MS (pos.
mode, DCTB): m/z (%) = 706 (100) [M]?, 707 (50)
[M ? H]?; HRMS: calculated for C42H26N8O4 706.2077,
found 706.2078.
d6): d = 173.0 (C=O), 172.2 (C=O), 144.5 (C=N), 143.1,
135.2, 132.7, 129.8, 128.5, 128.1, 126.7, 126.1, 121.8,
114.7, 66.6 (–CH), 54.5 (–CH) ppm. Anal Calcd for
C42H26F6N6O4. C, 63.64; H, 3.31; N, 10.60; found C,
63.17; H, 3.74; N, 10.67.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-(1,4-Phenylene)bis[3a,6a-
dihydro-3-(4-nitrophenyl)-1-phenylpyrrolo[3,4-c]pyrazole-
4,6(1H,5H)-dione] (13g, C40H26N8O8)
(3aR*,6aR*,3a0S*,6a0S*)-4,40-[(4,1-Pheny-
lene)bis(3a,4,6,6a-tetrahydro-4,6-dioxo-1-phenylpyrrolo-
[3,4-c]pyrazole-5,3(1H)-diyl)]bis[phenyl acetate]
(13k, C44H32N6O8)
Orange powder; yield 185 mg (99%); m.p.: 307–309 °C
(dec.); Rf = 0.43 (ethyl acetate–n-hexane 1:2); IR (KBr):
Light-brown crystalline solid; yield 195 mg (quant.); m.p.:
ꢀ
m ¼ 3; 074 (arom. C–H), 1,724 (C=O), 1,595 (C=N), 1,515,
216–218 °C (dec.); Rf = 0.25 (ethyl acetate–n-hexane
1
1,500, 1,340, 1,292, 1,192, 850, 750, 690 cm-1; H NMR
1:3); IR (KBr): m ¼ 3; 066 (arom. C–H), 1,722 (C=O),
ꢀ
(400 MHz, DMSO-d6): d = 8.29 (d, J = 8.0 Hz, 4H), 8.21
(d, J = 8.3 Hz, 4H), 7.56 (d, J = 7.4 Hz, 4H), 7.44 (s,
4H), 7.35 (t, J = 7.6 Hz, 4H), 7.00 (t, J = 6.6 Hz, 2H),
5.70 (d, J = 10.9 Hz, 2H), 5.40 (d, J = 11.0 Hz, 2H) ppm;
13C NMR (100 MHz, DMSO-d6): d = 173.0 (C=O), 171.8
(C=O), 147.8 (C=N), 144.3, 142.2, 137.4, 132.2, 129.6,
128.2, 128.0, 124.2, 122.0, 114.7, 66.3 (–CH), 53.9
(–CH) ppm; MALDI-MS (pos. mode, DCTB): m/z
(%) = 746 (100) [M]?, 747 (50) [M ? H]?; HRMS:
calculated for C40H26N8O8 746.1874, found 746.1869.
1,599 (C=N), 1,514, 1,498, 1,369, 1,199, 752, 692 cm-1
;
1H NMR (300 MHz, DMSO-d6): d = 8.05 (d, J = 8.7 Hz,
4H), 7.52 (d, J = 8.4 Hz, 4H), 7.45 (s, 6H), 7.35 (t,
J = 7.3 Hz, 4H), 7.26 (d, J = 8.7 Hz, 4H), 6.95 (t, J =
7.3 Hz, 2H), 5.54 (d, J = 11.1 Hz, 2H), 5.37 (d,
J = 11.1 Hz, 2H) ppm; 13C NMR (100 MHz, DMSO-d6):
d = 173.3 (C=O), 172.3 (C=O), 151.8 (C=N), 145.1,
143.9, 129.7, 128.9, 128.5, 122.7, 121.4, 114.5, 66.4
(–CH), 54.7 (–CH), 21.5 (COCH3) ppm. Anal Calcd for
C44H32N6O8. C, 68.39; H, 4.17; N, 10.88; found C, 68.23;
H, 4.61; N, 10.75.
(3aR*,6aR*,3a0S*,6a0S*)-5,50-(1,4-Phenylene)bis[3a,6a-
dihydro-3-(4-methoxyphenyl)-1-phenylpyrrolo[3,4-c]-
pyrazole-4,6(1H,5H)-dione] (13h, C42H32N6O6)
_
Acknowledgments Abant Izzet Baysal University, Directorate of
Research Projects Commission (BAP grant no. 2007.03.03.260) and
¨
_
TUBITAK (Turkish Scientific and Technological Research Council)
(grant no. 106T645) are gratefully acknowledged for financial sup-
port. The authors also thank Professor T. A. Jenny (Department of
Chemistry, University of Fribourg, Switzerland) and Professor D. W.
Knight (School of Chemistry, Cardiff University, UK) for HRMS
measurements.
Light-orange–brown crystalline solid; yield 165 mg (92%);
m.p.: 173–175 °C (dec.); Rf = 0.25 (ethyl acetate–n-hex-
ꢀ
ane 1:3); IR (KBr): m ¼ 3; 057 (arom. C–H), 1,724 (C=O),
1,597 (C=N), 1,514, 1,498, 1,367, 1,176, 835, 752,
1
692 cm-1; H NMR (300 MHz, DMSO-d6): d = 7.95 (d,
J = 8.2 Hz, 4H), 7.67–6.80 (m, 18H), 5.44 (d, J =
11.5 Hz, 2H), 5.32 (d, J = 10.8 Hz, 2H), 3.79 (s,
6H) ppm; 13C NMR (100 MHz, DMSO-d6): d = 172.6
(C=O), 172.1 (C=O), 160.9 (C=N), 145.5, 144.6, 129.7,
129.4, 128.7, 128.5, 123.6, 121.0, 119.5, 114.8, 114.6,
114.4, 66.5 (–CH), 56.0 (OCH3), 55.1 (–CH) ppm. Anal
Calcd for C42H32N6O6. C, 70.38; H, 4.50; N, 11.73; found
C, 70.11; H, 4.75; N, 11.49.
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