One-pot synthesis of new acid photogenerators for Rhodamine laser dyes fluorescence activation

Article abstract of DOI:10.1016/j.dyepig.2016.09.018

New aryl(hetaryl)pyrazolines fitted for fluorescence activation of Rhodamine laser dyes have been obtained via one-pot tandem Michael addition of two arylhydrazine molecules with 2-(4′-R-cinnamyliden)-2Н-furo[3,2-?]coumarin-3-ones. These aryl(hetaryl)pyra

Full text of DOI:10.1016/j.dyepig.2016.09.018

Accepted Manuscript
One-pot synthesis of new acid photogenerators for Rhodamine laser dyes
fluorescence activation
Valerii F. Traven, Natalya A. Pozharskaya, Natalya P. Solovjova, Roman A. Novikov,
Michael G. Medvedev, Vladimir V. Chernyshev, Sergei M. Dolotov, Ivan V. Ivanov
PII:
S0143-7208(16)30677-5
10.1016/j.dyepig.2016.09.018
DYPI 5470
DOI:
Reference:
To appear in: Dyes and Pigments
Received Date: 22 June 2016
Revised Date: 6 September 2016
Accepted Date: 7 September 2016
Please cite this article as: Traven VF, Pozharskaya NA, Solovjova NP, Novikov RA, Medvedev MG,
Chernyshev VV, Dolotov SM, Ivanov IV, One-pot synthesis of new acid photogenerators for Rhodamine
laser dyes fluorescence activation, Dyes and Pigments (2016), doi: 10.1016/j.dyepig.2016.09.018.
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ACCEPTED MANUSCRIPT

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1
One-pot synthesis of new acid photogenerators for Rhodamine laser dyes
fluorescence activation
a*
а
а
Valerii F. Traven , Natalya A. Pozharskaya , Natalya P. Solovjova , Roman A.
Novikovb, Michael G. Medvedevc, Vladimir V. Chernyshevd,e, Sergei M. Dolotov , Ivan
a
V. Ivanov a
аD.I. Mendeleev University of Chemical Technology of Russia, Miusskaya Sq., 9, Moscow, Russian
Federation
b
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilov st., 119991
Moscow, Russia
cA. N. Nesmeyanov Institute of Organoelement Compounds RAS, Moscow, Vavilova str., 28, Russian
Federation
dDepartment of Chemistry, M.V. Lomonosov Moscow State University, GSP-1, Leninskie Gory, 1-3,
Moscow, Russian Federation
eA.N.Frumkin Institute of Physical Chemistry and Electrochemistry RAS, Leninsky prospect, 31,
Moscow, Russian Federation
Supporting Information
ABSTRACT:
New aryl(hetaryl)pyrazolines fitted for fluorescence activation of Rhodamine laser dyes
have been obtained via one-pot tandem Michael addition of two arylhydrazine molecules
with
2-(4’-R-cinnamyliden)-2Н-furo[3,2-с]coumarin-3-оnes.
These
aryl(hetaryl)pyrazolines do not undergo tautomeric transformations both in organic
solvents and in polymer films and behave themselves as effective acid photogenerators
of Rhodamine dyes fluorescence activation. New aryl(hetaryl)pyrazolines can be used in
the fabrication of two-photon volumetric optical memory materials.
Keywords:

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One-pot synthesis
Aryl(hetaryl)pyrazolines
Michael addition
Photodehydrogenation
Fluorescence
Optical memory
1. Introduction
Optical disks (ODs) are widely used for archival information storage of WORM
type (Write Once Read Many), which ensure multiple readouts of the recorded optical
data. Increasing the information capacity of ODs is an urgent problem. It is related to the
design of multilayer light-sensitive recording media. The media based on photochemical
transformations of organic compounds are intended as the recording layers for such ODs,
since light-sensitive photofluorescent materials appear to be the most promising for the
design of the WORM OD recording media for 3D bitwise archive optical memory. They
are based on heterocyclic organic compounds that have no luminescence in their initial
form but form fluorescent photoproducts. Reverse fluorescence behavior of recording
media is also applicable. Moreover, organic photosensitive media have, in principle, a
higher resolution than the currently used temperature-sensitive materials. The most
perspective type of WORM materials recording media is composed of two components: a
photogenerator of acidity (PAG) and a dye precursor (DP). The DP molecules are

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colorless and stable in neutral media, however they become strongly colored and
fluorescing in the presence of an acid produced by the light-sensitive PAG molecules
when they are exposed to light [1-10].
4-Hydroxy-3-pyrazolinylcoumarins 1 have been earlier found to undergo
quantitative photodehydrogenation to 4-hydroxy-3-pyrazolylcoumarins in the presence of
CCl4 or C2Cl6 [11]. Due to the reaction they behave themselves as photogenerators of H+-
acidity that are able to generate highly fluorescent Rhodamine dye from its lactone form
under UV light irradiation both in organic solvents and in polymer films. However, 4-
hydroxycoumarin derivatives 1, depending on the media composition, have been found to
undergo hydroxy-keto tautomeric transformations. For example, 4-hydroxy-3-
pyrazolinylcoumarin 1a shown below exist in hydroxy-form in toluene and in keto-form
in dimethylformamide. Meanwhile, as we have earlier shown, substrates 1 can effectively
operate as acid photogenerators being only in hydroxy-form [11c]. Therefore, search of
new acid photogenerators for archival recording process is in a obvious demand.
1a, hydroxy-form
1a, keto-form
In this paper we report a new way to synthesize effective acid photogenerators.

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“Substitution” of a furanone ring for a pyrazole one in 2H-furo[3,2-c]coumarin-3-one
derivatives via tandem interaction of 2-(4’-R-cinnamyliden)-2Н-furo[3,2-с]coumarin-3-
оnes with 2 mols of arylhydrazines chlorohydrates provides a new one-pot regioselective
route to 2-phenylchromeno[4,3-c]pyrazol-4(2Н)-one derivatives. These derivatives
possess photosensitivity, form nonfluorescent photoproducts, do not undergo tautomeric
trnsformations in different medium and behave themselves as more effective
photogenerators of Rhodamine dyes lactone opening.
2. Experimental
2.1. Materials
The deuterated solvent (CDCl3) for NMR spectroscopy was obtained from Merck.
The lactone form of Rhodamine B was used as precursor of flurescent laser dye (high
purity grade, Aldrich). Hexachloroethane was used as an halogen-containing
additive(high purity grade, Aldrich). The other chemicals were Aldrich HPLC or spectral
grade and were used without further purification.
Polymeric films were fabricated using the pouring method. A solution containing
poly(methyl methacrylate), the lactone form of Rhodamine B, pyrazoline 7a, as well as
an halogen derivative in a mixture of toluene—ethyl acetate (1 : 1), was poured onto a
horizontally placed Petri dish, afterwards the solvent was evaporated. The films were
removed from the substrate before undergoing irradiation.
2.2. General Equipment

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1H, 13C and 15N NMR spectra were recorded on «Bruker AMX-III 400» and 300 —
«Bruker AVANCE-II 300» spectrometers in CDCl3 containing 0.05% Me4Si as the
internal standard. Determinations of structures and stereochemistry of obtained
1
13
15
compounds and assignments of H, C and N signals were made with the aid of COSY
(2D 1H,1H homonuclear shift correlation spectroscopy), TOCSY (2D 1H,1H
homonuclear total shift correlation spectroscopy), NOESY (Nuclear Overhauser Effect
(NOE) based 2D 1H,1H homonuclear shift correlation spectroscopy), HSQC (2D 1H-
detected 1H,13C correlation via heteronuclear single quantum coherence and double
inept transfer), edited-HSQC (HSQC with CH multiplicity editing), HMBC (2D 1H-
detected 1H,13C multiple bond correlation via heteronuclear zero and double quantum
coherence optimized on long range couplings), LR-HMBC (long range HMBC optimized
on very small couplings), 15N-HMBC (1H,15N HMBC using natural abundance of 15N-
isotope ) and 15N-LR-HMBC (long range 1H,15N HMBC optimized on very small
couplings) spectra. Mass-spectra were recorded on Kratos MS-30, ionizing energy equal
to 70 eV. Chromato-mass spectra have been obtained on spectrometer PE SCIEX API165
(ELSD UV254), column Synergi 2u Hydro-RP Mercury, 20x2.0 mm. Electronic
absorption spectra were recorded on an APELPD_303UV spectrometer and fluorescent
spectra – on Cary Eclipse (Varian) spectrofluorimeter. Photo-irradiation was carried out
using an L 5283 xenon lamp (HAMAMATZU lamp) through a light filter to select light
in UV region at 360 nm and in the visible region at 420 nm with corresponding glass
filters. Analytical thin layer chromatography was performed on silica gel plates (Merck,

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Kieselgel 60, 0.25 thickness) with F254 indicator. Column chromatography was
performed on silica gel (Merck, Kieselgel 60, 70-200 or 230-400 mesh).
2.3. Single crystal X-ray analysis
The X-ray crystal structure analysis was made on a Bruker SMART APEX2 CCD
(MoKα radiation, λ = 0.71073 Å, graphite monochromator, T = 120 K, 2θmax = 56.5°).
The structure was solved in Olex2 [12] with the ShelXT [13] structure solution program
using Direct Methods and refined with the ShelXL [14] refinement package using Least
Squares minimization. Non-hydrogen atoms were refined anisotropically. Crystal data for
7a: C33H25Cl3N4O2 (M =615.92 g/mol): triclinic, space group P-1 (no. 2), a = 10.2992(7)
Å, b = 10.6702(8) Å, c = 14.7989(11) Å, α = 76.790(2)°, β = 86.793(2)°, γ =
68.3190(10)°, V = 1470.55(19) Å3, Z = 2, Dcalc = 1.391 g/cm3, 16939 reflections
measured (2.828° ≤ 2Θ ≤ 56.56°), 7312 unique (Rint = 0.0334, Rsigma = 0.0520) which
were used in all calculations. The final R = 0.0584 (I > 2σ(I)) and wR2 = 0.1183 (all
data). Crystal structure has been deposited with Cambridge Crystallographic Data Center
(CCDC reference number 1454727).
2.4. Powder diffraction study
Powder pattern was measured with Huber G670 Guinier camera (Cu Kα1 radiation,
λ = 1.54059 Å, transmission mode) in the 3 – 70o 2θ region. Orthorhombic unit-cell
dimensions were determined using three indexing programs: TREOR90, ITO and

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AUTOX. Space group Pbca was assigned taking into account the systematic extinctions.
The crystal structure was solved with the use of simulated annealing technique and
molecular model taken from the single-crystal structure of solvated form. The solution
found was refined with the program MRIA via a bond-restrained Rietveld refinement (see
Fig. 2B in SI) in the same way as was reported earlier. Crystal data for solvent free 7a:
C32H24N4O2 (Mr =496.55 g/mol): orthorhombic, space group Pbca (no. 61), a = 48.703(4)
Å, b = 14.5829(19) Å, c = 7.1614(11) Å, V = 5086.2(11) Å3, Z = 8, Dcalc = 1.297 g/cm3,
powder pattern was measured in 3 – 70o 2θ region with 0.01o step. The final R-factors
are: Rp = 0.0231, Rwp = 0.0297, Rexp = 0.0177, χ2 = 2.83. Crystal structure has been
deposited with Cambridge Crystallographic Data Center (CCDC reference number
1443154).
3. Synthesis
We have found a novel way to synthesize pyrazolines of coumarin series.
Interactions of coumarin α,β-unsaturated carbonyl derivatives with arylhydrazines is
known to provide promising route to new heterocyclization reactions [15-21]. For
example, interaction of 2,3-dihydrofuro[3,2-с]coumarin-3-оne 2 and its benzilydene
derivatives 3 with arylhydrazines has earlier been studied [22,23]. Compound 2 reacts
with phenylhydrazine in acetic acid or in toluene with formation of hydrazinoimine 4 as
the only product both at excess of phenylhydrazine and at reactants equimolar ratio [22].

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Compounds 3 interact with phenylhydrazine in toluene with formation of ozazone 5
[23]. It should be noted, that furanone ring opening undergoes in both reactions without
breaking of C(4, coumarin)-O(furanone) bond.
2
3
4
5
Another path of coumarin derivatives interaction with arylhydrazines is reported in this
paper. Reaction of cinnamylidene derivatives 6 with arylhydrazine chlorohydrates
undergoes with “substitution” of furanone ring in 2H-furo[3,2-c]coumarin-3-one
fragment for pyrazole cycle. The C(4, coumarin)-O(furanone) bond and C-C(furanone)
bond turned to be substituted for C=N and C-N bonds respectively along heating of
compounds 6 with 2.5 mols arylhydrazine chlorohydrates in ethanol for 2 hours. 3-(5-
Benzyl-1-phenyl-4,5-dihydro-1Н-pyrazol-3-yl)-2-phenylchromeno[4,3-c]pyrazol-4(2Н)-
ones 7 (6) have been found as predominant products of the reaction with yields up to 53%
(Scheme 1).

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Scheme 1. Synthesis of 3-(4,5-dihydro-1Н-pyrazol-3-yl)-chromeno[4,3-c]pyrazol-4(2Н)-
ones 7.
One can suggest that interaction of compounds 6 with arylhydrazines chlorohydrates
undergoes by the Scheme 2.
Scheme 2. Proposed mechanism of 3-(4,5-dihydro-1Н-pyrazol-3-yl)-chromeno[4,3-
c]pyrazol-4(2Н)-ones 7 formation.

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On the first step 2Н-furo[3,2-с]coumarin-3-оne 6a reacts with phenylhydrazine as
a nucleophile at position 4 of coumarin fragment, since the coumarin 3-4 double bond is
strongly activated to such Michael addition by two carbonyl functions that are conjugated
with this bond. Michael addition is then followed by furanone cycle opening and
intermediate enolate-ion formation. Subsequent intramolecular cyclization of
phenylhydrazido-function to pyrazole ring leads to 3-cinnamoyl-2-phenylchromeno[4,3-
c]pyrazol-4(2Н)-one unit. Its tandem interaction with the second mol of arylhydrazine
provides formation of the final compound 7a.
The proposed mechanism (Scheme 2) of interaction 2H-furo[3,2-c]coumarin-3-one
cinnamylidene derivatives with arylhydrazine chlorohydrates is in accordance with
exclusive formation 2-phenylchromeno[4,3-c]pyrazol-4(2Н)-one key fragment of the
compounds 7 in the reaction. The reported route of 2-phenylchromeno[4,3-c]pyrazol-
4(2Н)-one derivatives syntheses is based on interaction 3-acetyl-4-hydroxycoumarin
phenylhydrazone with phenylhydrazine chlorohydrate. It undergoes with formation of
mixture of 2-phenylchromeno[4,3-c]pyrazol-4(2Н)-one and 1- phenylchromeno[4,3-
c]pyrazol-4(1Н)-one derivatives [24, 25].
4. Structural aspects
The composition of the final products 7 was established by means of elementary analyses
and HRMS. New pyrazolines of coumarin series possess very poor crystalization ability.
1
13
15
Therefore, structures of all compounds were determined by H, C and N NMR

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spectroscopy using 1D and 2D HSQC and HMBC spectra. Structure of the compound 7a
was determined in much more detail with use of DEPT, COSY, TOCSY, NOESY,
editing-HSQC, LR-HMBC, 15N-HMBC and 15N-LR-HMBC spectra (SI, p.8). Key cross-
peaks and correlations in 2D NMR spectra are shown in Fig. 1 by color arrows. Looking
15
for molecular structures of the final compounds, 7b sample labelled by two N-atoms
(N11 and N22) has been obtained in the reaction of 6b with of 15NH2-NH-C6H5.HCl (SI,
p.3).
15N-LR-HMBC
15N-HMBC
LR-HMBC
HMBC
H
H
H
no NOE
NOE
H
H
+
N
N
N
H
N
H
H
H
H
H
H
H
H
H
O
O
H
H
Fig. 1. Key cross-peaks and correlations in 2D NMR spectra for the 7a structure
assignments indicated by arrows (blue – NOE; light blue – absence of NOE; red –
HMBC; pink – LR-HMBC; green – 15N-HMBC; orange – 15N-LR-HMBC).
Crystallization of the compounds 7 from different solvents has not provided crystals
suitable for X-ray diffraction studies, since powder samples have only been isolated
along the procedure. However, crystals suitable for X-ray diffraction studies have been
obtained for compound 7a chloroform solvate by slow concentration of its chloroform
solution. The molecular structure of 7a chloroform solvate is represented in Fig. 2

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(structure A). Сhromeno[4,3-c]pyrazol-4-one fragment is almost planar, it forms angles
of 57° with the plane of the phenyl and of 31° with the plane of the C21–N22 double
bond, which, in its turn, forms an angle of 8° with the plane of the neighboring phenyl.
Molecule conformation is stabilized by intramolecular N22-pi(C13) stacking with N22-
C13 distance being 2.93 Å and intramolecular hydrogen bond (C31–H…O2) with C…O
distance being 3.106(2) Å and C–H…O angle being 140°. Analysis [26, 27] of calculated
electron density (PBE0-D3/TZVP, see SI) estimates this CH…O interaction to be ~6
kcal/mol (see S4 for details), thus being a strong hydrogen bond [28]. The crystal
structure of 7a chloroform solvate is stabilized by C–H…N and C–Cl…N interactions of
7a with chloroform, intermolecular C–H…O bonds and chromenone-phenyl π-stacking
(SI, p. 4, 5).
A
B
Fig. 2. A - General view of compound 7a in its chloroform solvate given with atomic
displacement ellipsoids at p=50%; B - Molecule conformation of 7a in its pure form

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(powder XRD study).
Molecule conformation of 7a in its pure form has been found from powder XRD study
following the procedure used by us earlier (Fig. 2, structure B) [29]. This conformation is
quite different from that in the chloroform solvate (Fig. 2, structure A). The main change
is the twist around C19-C21 bond. Although, conformation is again stabilized by similar
N22-pi(C13) stacking and rather strong C31–H…O2 bond, however, involving a
different hydrogen.
5. Compounds 7 as photogenerators of H+-acidity
Compounds 7 possess photochemical activity and behave themselves as acid
photogenerators (abbreviated in this paper as PAGs). As it is seen in Fig.3, they change
both absorption and emission spectra in carbon tetrachloride or in toluene + C2Cl6 (2-5%)
under illumination at the absorption maximum of compound 7.
Due to
phototransformation of compound 7a emission of its solution (λmax at 505 nm) is
disappeared along illumination since photoproduct practically has no fluorescence (λmax
at 400 nm).
Being illuminated in the same solutions in the presence of acid-base indicators,
Thymol Blue, for instance, compounds 7 provide coloring related to the increase of
solution acidity. The compounds 7 activate also intensive fluorescence of laser

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Rhodamine dyes, namely Rhodamine B, when illuminated in the presence of Rhodamine
lactone forms. These forms are known to be easily converted into open forms in the
presence of acids [30].
Fig. 3. Electronic absorption (left) and emission (right, excitation wavelengths = 305 and
400 nm ) spectra of compound 7a in toluene (+ C2Cl6) solution before (1) and after (2-
10) irradiation at 420 nm
The changes in the electronic absorption and emission spectra of toluene (+C2Cl6)
solution, containing compound 7a and Rhodamine B lactone form are shown in Fig. 4:
the increase in intensity of the absorption band at 560 nm and of the emission band at 590
nm is due to an increase in the concentration of the Rhodamine B open form. It is
important that similar irradiation of Rhodamine B lactone form in toluene containing
C2Cl6 without compound 7a does not result in any spectral changes. It should be noted
that electronic absorption of compound 7a photoproduct is shifted into the shorter

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wavelengths (as it is seen in Fig. 3) and do not intersect emission band of Rhodamine B
open form. These results provide good perspectives for new pyrazolines to be used in
archival optical recording media as acid photogenerators. As we have shown, compounds
7 effectively activate Rhodamine B fluorescence in polymer films as well.
Fig. 4. Electronic absorption (left) and emission (right, excitation wavelength =
560 nm) spectra of toluene (+C2Cl6) solution, containing compound 7a and Rhodamine B
lactone form before (1) and after (2-6) irradiation at 420 nm
Irradiation of both polymethylmethacrylate (PMMA) and polystyrene films containing
compound 7a, hexachloroethane and Rhodamine B lactone form at 360 nm provides
coloring and fluorescence activation of the polymer films. Absorption and emission
spectra of the PMMA film along illumination are shown in Fig. 5.

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Fig. 5. Emission (right) spectra of PMMA film, containing compound 7a,
Rhodamine B lactone form and C2Cl6 before (1) and after (2-13) irradiation at 420 nm
(excitation wavelengths = 400 and 560 nm )
Two organic reactions which initiate the coloring of a PMMA film, namely
photodehydrogenation of pyrazoline derivative 7a and Rhodamine B lactone ring
opening, occur in a polymer matrix (Scheme 3).

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Ph
Ph
N
N
hv
N
N
+
H+
C2Cl6
Ph
Ph
7a
+
Et2N
NEt2
O
NEt2
O
Et2N
H+
O
COOH
O
Scheme 3. Acid photogeneration by new coumarinylpyrazolines for Rhodamine laser dye
fluorescence activation
PAGs are widely used for a vast range of practical applications including optical
information recording, microlithographic imaging with photoresists, photodynamic
therapy and photocontrol of enzymatic activity [31]. For instance, arylsulfonium salts
provide acid generation under illumination and efficiently initiate Rhodamine
fluorescence activation in optical information recording materials. Photochromic
bis(thiazolyl)benzothiophene derivatives have been found as effective photoinitiators for
the cationic polymerization of cyclohexene oxide. However, the reported PAGs absorb
light in the near UV-region which is not fitted for some (e.g. biochemical) applications.
In opposite, compounds 7 are photosensitive at 360-420 nm, have no tautomeric
transformation, form nonfluorescent photoproduct and look therefore as rather
perspective PAGs.
Moreover, new coumarinylpyrazolines 7 can be useful in optical information

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recording not only as acid photogenerators. In opposite to 4-hydroxy-3-
pyrazolinylcoumarins 1 that form fluorescent products under illumination, compounds 7
are dehydrogenated with complete disappearing of intensive fluorescence as it is seen in
Fig. 3. This property provides application of coumarinylpyrazolines 7 in optical
information recording without use of Rhodamine lactone form or any other additional
source of fluorescence.
6. Synthetic procedures
2H-Furo[3,2-c]chromene-3,4-dione 2 has been obtained as reported in [22]. Below
synthetic protocols are given for compounds 6a and 7a. Synthesis of other compounds is
described in SI.
6.1. Synthesis of compound 6a
Cinnamaldehyde ( 2 mmols) in 3 ml acetic acid has been added by dropwise to solution
of 2H-furo[3,2-c]chromene-3,4-dione 2 (1.5 mmol) in 15 ml acetic acid. The mixture has
been boiled for 1 h. The formed precipitate was filtered off and recrystallized from acetic
acid.
2-[3-phenylprop-2-en-1-ylidene]-4H-furo[3,2-c]chromene-3,4(2H)-dione 6a: Yield
о
1
30% (AcOH), m.p. 229-230 С. H NMR (200 MHz, CDCl3): 7.01 (dd, 1H, H(α), 3JH(α),
4
3
3
=11.6, JCαH, CγH=0.6), 7.17 (d, 1H, H(γ), JH(β),H(γ)=15.8),7.34 (dd, 1H, H(β), JHα,
H( β)
Hβ=11.6, 3JH(β), H(γ)=15.8), 7.38-7.65 (m, 7H, H(2′), H(3′), H(4′), H(5′), H(6′), H(6), H(8)),
7.82 (m, 1H, H(7)), 8.09 (dd, 1H, H(5), 3JH(5),H(6)=8.0, 4JH(3), H(7)=2.0). MS, m/z: 316 ([М],
70), 317 ([M+1] 20). Found(%): C, 76.01; H, 3.80. Calc. for C20H12O4(%): C, 75.94; H,

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3.82.
6.1. Synthesis of compound 7a
Compound 6a (1 mmol) and arylhydrazine chlorohydrate (2.5 mmol) have been boiled
for 2 h in 20 ml of ethanol in the presence of 1 ml of triethylamine. The formed
precipitate has been filtered off and recrystallized from ethanol.
3-(5-benzyl-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)-2-phenylchromeno[4,3-c]pyrazol-
4(2H)-one 7а: Yield 53%(EtOH), m.p. 155-156оС. 1H NMR (200 MHz, CDCl3+DMSO-
2
3
d6): 2.70 (dd, 1H, Ha(13), JH(a),H(b)=14.0, JH(b),CH=2.0), 2.93 (dd, 1H, Hb (13),
2JH(a),H(b)=14.0, 3JH(a),CH=8.0), 3.58 (narrow m, 2H, CH2(11)), 4.64 (m, 1H, H(12)), 6.64(d,
2H, H(2′′′), H(6′′′), 3JH,H=8.0), 6.77 (t, 1H, H(4′′′), 3JH,H=8.0), 7.05-7.55(m, 15H, H(3′′′),
H(5′′′), H(2′′), H(6′′), H(3′′), H(5′′), H(4′′), H(2′), H(3′), H(4′), H(5′), H(6′), H(6), H(7),
H(8)), 8.04 (dd, 1H, H(5) ,3J5,6=8.0, 4J5,7=2.0). MS, m/z: 497,5 (100) [M+1]. Found (%):
C, 77.31; H, 4.86; N, 11.30. Calc. for C32H24N4O2(%): C, 77.40; H, 4.87; N, 11.28.
7. Conclusions
In conclusion, we report “substitution” of a furanone ring for a pyrazole one in 2H-
furo[3,2-c]coumarin-3-one derivatives via one-pot tandem reaction of 2-(4’-R-
cinnamyliden)-2Н-furo[3,2-с]coumarin-3-оnes with 2 mols of arylhydrazines
chlorohydrates. The reaction provides new regioselective route to 2-phenylchromeno[4,3-
c]pyrazol-4(2Н)-one derivatives.
These aryl(hetaryl)pyrazolines do not undergo

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20
tautomeric transformations both in organic solvents and in polymer films and behave
themselves as effective acidity photogenerators of Rhodamine dyes fluorescence
activation. In this sense the new aryl(hetaryl)pyrazolines look to be more effective in the
fabrication of two-photon volumetric optical memory materials when compared with 4-
hydroxy-3-pyrazolinylcoumarins 1.
Acknowledgment
Financial was provided by the grant №10-03-00734-а from Russian Foundation for
Basic Research. The quantum-chemical calculations were performed on IBM Blue
Gene/P supercomputer at Moscow State University’s Faculty of Computational
Mathematics and Cybernetics.
AUTHOR INFORMATION
Corresponding author
E-mail: valerii.traven@gmail.com
Notes
The authors declare no competing financial interest.
References
[1] Walker E, Dvornikov AS, Coblentz K, Esener S, Rentzepis PM. Toward terabyte two-photon 3D
disk. Optics express 2007; 15(19):12264-76.

ACCEPTED MANUSCRIPT
21
[2] Walker E, Dvornikov A, Coblentz K, Rentzepis P. Terabyte recorded in two-photon 3D disk.
Applied Optics 2008; 47:4133-41.
[3] Zhou W, Kuebler SM, Braun KL,Yu T, Cammack JK, Ober CK, Perry JW,Marder SR. An Efficient
Two-Photon-Generated Photoacid Applied to Positive-Tone 3D Microfabrication. Science 2002;
296:1106-9.
[4] Akiba M, Dvornikov AS, Rentzepis PM. Formation of oxazine dye by photochemical reaction of N-
acyl oxazine derivatives. Journal of Photochemistry and Photobiology A: Chemistry 2007; 190: 69-76.
[5] Scaiano JC, Laferriere M, Ivan MG, Taylor GN. A Protocol for the Verification of Acid Generation
in 157 nm Lithography. Macromolecules 2003; 36: 6692-4.
[6] a) Barachevsky VA. Photofluorochromic spiro-compounds and their application J. Fluorescence
2000; 10: 185-191.
b) Barachevsky VA, Alfimov MV, Nazarov VB. Light-sensitive organic recording media for
luminescent readout of optical information. Opt. Mem.Neur. Networks 1998; 7:205-212.
c) Barachevsky VA, Alfimov MV, Nazarov VB. Light-sensitive organic recording media for
luminescent readout of optical information Sci.Appl.Photo. 1999; 41: 299-309.
[7] Kevin D, Belfield K, Schafer J. A New Photosensitive Polymeric Material for WORM Optical Data
Storage Using Multichannel Two-Photon Fluorescence Readout. Chem Mater 2002; 14: 3656- 62
[8] Ahn KD, Lee JH, Cho I, Park KH, Kang JH, Han DK, Kim JM. Norbornene-Derived Quinizarin
Dye Molecules for Photoimaging in Polymer Films Based on Chemical Amplification. Journal of
Photopolymer Science and Technology 2000; 13:493–6.
[9] a) Rentzepis PM, Dvornikov AS. Dye precursor molecules chemically reactive with the light-altered
form of light-sensitive molecules to form stable fluorescent dye, particularly for optical memories
including two-photon three-dimensional optical memories. US Patent 2002; 6,432,610 B1.
b) Rentzepis PM, Dvornikov AS. Dye precursor molecules chemically reactive with the light-altered

ACCEPTED MANUSCRIPT
22
form of light-sensitive molecules to form stable fluorescent dye, particularly for optical memories
including two-photon three-dimensional optical memories. US Patent 2003; 2003/0073031 A1.
[10] Magnitskii S, Magnitskii N, Malkin J, Levic H, Tarasishin A, Pakulev A, Angerluts A, Malakhov
V, Shubin V, Kozenkov V, Kvasha M, Binjukov V, Sokoljuk N, Chernobrod B, Lezhnev A,
Dorozhkina G, Pebalk D. Medium for fluorescent read-only multilayer optical infomation carrier and its
manufacturing method 2001; WO200129837 A1.
[11] a) Traven VF, Ivanov IV, Pavlov AS, Manaev AV, Voevodina IV, Barachevskii VA. Quatitative
Photooxidation of 4-Hydroxy-3-pyrazolinyl-coumarins into Pyrazolyl-derivatives. Mend Communs
2007; 17: 345-346.
b) Traven VF, Ivanov IV. New reaction of photoaromatization of aryl- and hetarylpyrazolines. Russ
Chem Bull Int Ed 2008; 57: 1063-1069.
c) Traven VF, Dolotov SM, Ivanov IV. Fluorescence activation of Rhodamine lactone forms by
photoaromatization of aryl(hetaryl)pyrazolines. Izv Russ Acad Sci Ser Khim 2016; 65(3): 735-40.
[12] Dolomanov OV, Bourhis LJ, Gildea RJ, Howard JAK, Puschmann H. OLEX2: a complete structure
solution, refinement and analysis program. J Appl Crystallogr 2009;42:339–41.
doi:10.1107/S0021889808042726.
[13] Sheldrick GM. Crystal structure refinement with SHELXL. Acta Crystallogr Sect C Struct Chem
2015;71:3–8. doi:10.1107/S2053229614024218.
[14] Sheldrick G. A short history of SHELX. Acta Crystallogr Sect A 2008;64:112–22.
[15] Levai A, Jeko J, Brahmbhatt DI. J Synthesis of 1-substituted 5-aryl-3-(3-coumarinyl)-2-pyrazolines
by the reaction of 3-aryl-1-(3-coumarinyl)propen-1-ones with hydrazines. Heterocyclic Chem 2005;
42(6): 1231-35.
[16] Traven VF, Manaev AV, Voevodina IV, Ohrimenko IN. Synthesis and structure of new 3-
pyrazolinyylcoumarins and 3-pyrazolinylcoumarins and 3-pyrazolinyl-2-quinolones. Russ Chem Bull

ACCEPTED MANUSCRIPT
23
Int Ed 2008; 57: 1508-15.
[17] Traven VF, Ivanov IV. New reaction of photoaromatization of aryl- and hetarylpyrazolines.
Russian Chem Bull Internat Ed 2008; 57(5): 1063-69.
[18] Lévai A, Jekő J. Synthesis of 5-aryl-1-carboxyphenyl-3-(3-coumarinyl)-2-pyrazolines. ARKIVOC
2009 (vi): 63-70.
[19] Khode S, Maddi V, Aragade P, Palkar M, Ronad PK, Mamledesai S, Thippeswamy AHM,
Satyanarayana D. Synthesis and pharmacological evaluation of a novel series of 5-(substituted) aryl-3-
(3-coumarinyl)-1-phenyl-2-pyrazolines as novel anti-inflammatory and analgesic agents. European J
Med Chem 2009; 44(4): 1682-88.
[20] Xi G-L, Liu Z-Q. Antioxidant effectiveness generated by one or two phenolic hydroxyl groups in
coumarin-substituted dihydropyrazoles. European J Med Chem 2013; 68: 385-93.
[21] Bai S-Y, Dai X, Zhao B-X, Miao J-Y. Discovery of a novel fluorescent HSP90 inhibitor and its
anti-lung cancer effect. RSC Adv., 2014, 4, 19887-90.
[22] Kondratova NA, Solov’eva NP, Traven VF. Dihydrofuran ring opening in the reactions of 2,3-
dihydrofuro[3,2-c]coumarin-3-one with arylhydrazines. Russian Chem Bull Internat Ed 2010; 59(8):
1612-20.
[23] Kondratova NA, Traven VF, Posina MI, Solov'eva NP, Savelyev OU. Opening of furanone ring of
2,3-dihydrofuro[3,2-c]coumarin-3-one derivatives by arylhydrazines. Heterocyclic Communications
2012; 18(1): 1-5.
[24] Chantegrel B, Nadi A-I, Gelin S. 4-Oxo-1H-and-2H-[1]benzopyrano[4,3-c]pyrazoles. Preparation
from 4-hydroxycoumarin or 3-chromonecarboxylyc acid derivatives. Tetrahedron Letters 1983; 24: 381-
84.
[25] Colotta V, Cecchi L, Filacchioni G, Melani F, Palazzino G, Martini C, Giannaccini G, Lucacchini
A. Synthesis, binding studies, and structure activity relationships of 1-aryl- and 2-

ACCEPTED MANUSCRIPT
24
aryl[1]benzopyranopyrazol-4-ones, central benzodiazepine receptor ligands. J Med Chem 1988; 31(1):
1-3.
[26] Lyssenko KA. Analysis of supramolecular architectures: beyond molecular packing diagrams.
Mendeleev Commun 2012; 22(1): 1-7.
[27] Espinosa E, Molins E. Retrieving interaction potentials from the topology of the electron density
distribution: the case of hydrogen bonds. J Chem Phys 2000; 113: 5686-94.
[28] Desiraju GR, Steiner T. The weak hydrogen bond: in structural chemistry and biology, first publ. in
paperback. International Union of Crystallography monographs on crystallography; Oxford University
Press: Oxford, 2001.
[29] (a) Milevsky BG, Solov’ova NP, Chibisova TA, Yarovenko VN, Zayakin ES, Chernyshev VV,
Krayushkin MM, Traven VF. Hydrazones derived from thiooxamohydrazides and 3-formyl-4-
hydroxycoumarin: synthesis, structures, and fragmentation. Russ Chem Bull 2012; 61: 2311-21;
(b) Werner P-E, Eriksson L, Westdahl M. TREOR, a semi-exhaustive trial-and-error powder indexing
program for all symmetries. J Appl Crystallogr 1985; 18: 367-70;
(c) Visser JWJ. A fully automatic program for finding the unit cell from powder data. Appl Crystallogr
1969; 2: 89-95;
(d) Zlokazov VB. MRIAAU - a program for autoindexing multiphase polycrystals. J Appl Crystallogr
1992; 25(1): 69-72;
(e) Zlokazov VB. AUTOX — A program for autoindexing reflections from multiphase polycrystals.
Comput Phys Commun 1995; 85(3): 415-22;
(f) Zhukov SG, Chernyshev VV, Babaev EV, Sonneveld EJ, Schenk H. Application of simulated
annealing approach for structure solution of molecular crystals from X-ray laboratory powder data. Z
Kristallogr 2001; 216: 5-9.
[30] Traven VF, Ivanov IV, Dolotov SM, Kobeleva OI, Barachevsky VA. Aryl(hetaryl)pyrazolines as

ACCEPTED MANUSCRIPT
25
new photoacid generators for optical information recording. J Photochem Photobiol A: Chem 2014; 295:
34-9.
[31] a) Lee, C.-W.; Yuan, Z.; Ahn, K.-D.; Lee, S.-H. Color and Fluorescent Imaging of t-BOC-Protected
Quinizarin Methacrylate Polymers. Chem. Mater. 2002, 14, 4572-4575.
b) Kim, J.-M.; Chang, T.-E.; Kang, J.-H.; Park, K. H.; Han, D.-K.; Ahn, K.-D. Photoacid-Induced
Fluorescence Quenching: A New Strategy for Fluorescent Imaging in Polymer Films. Angew. Chem.,
Int. Ed. 2000, 39, 1780-1782.
(c) Nakashima T, Tsuchie K, Kanazawa R, Li R, Iijima S, Galangau O, Nakagawa H, Mutoh K,
Kobayashi Y, Abe J, Kawai T. Self-Contained Photoacid Generator Triggered by Photocyclization of
Triangle Terarylene Backbone. J Am Chem Soc 2015; 137(22): 7023-6;
(d) Yue X, Yanez CO, Yao S, Belfield KD. Photochemically Induced pH Imbalance in Cancer Cells”. J.
Am Chem Soc 2013; 135(6): 2112-5;
(e) Kohse H, Neubauer A, Pazidis A, Lochbrunner S, Kragl U. Photoswitching of enzyme activity by
laser-induced pH-jump. J Am Chem Soc 2013; 135(25): 9407-11.
[32] Kondratova NA, Kazheva ON, Aleksandrov GG, Chekhlov AN, D’yachenko OA, Traven VF.
Structure and condensation reactions of 2,3-dihydrofuro[3,2-c]coumarin-3-one. Russian Chem Bull
Internat Ed 2011; 60 (9): 1906-16.

ACCEPTED MANUSCRIPT
One-pot tandem Michael addition of two arylhydrazine molecules to
unsaturated ketone
New aryl(hetaryl)pyrazolines are effective acid photogenerators
New aryl(hetaryl)pyrazolines provide fabrication of optical memory
materials