Dihydrofuran ring opening in the reactions of 2,3-dihydrofuro[3,2-c] coumarin-3-one with arylhydrazines

Article abstract of DOI:10.1007/s11172-010-0285-y

2,3-Dihydrofuro[3,2-c]coumarin-3-one reacts with arylhydrazines via two routes. The corresponding hydrazones are formed from arylhydrazines in alcohol and nitrophenylhydrazines in acetic acid or toluene. With phenylhydrazine and para-tolylhydrazine in toluene, 2,3-dihydrofuro[3,2-c]coumarin-3-one reacts unusually undergoing dihydrofuran ring opening and the formation of the corresponding 3-(2-imino-1-(2-arylhydrazinyl)ethylidene)-chromane-2,4-diones. The solvatochromic properties of the synthesized compounds were studied using electronic absorption spectra and quantum chemical calculations.

Full text of DOI:10.1007/s11172-010-0285-y

Russian Chemical Bulletin, International Edition, Vol. 59, No. 8, pp. 1612—1620, August, 2010
1612
Dihydrofuran ring opening in the reactions
of 2,3ꢀdihydrofuro[3,2ꢀc]coumarinꢀ3ꢀone with arylhydrazines
N. A. Kondratova, N. P. Solov´eva, and V. F. Traven
D. I. Mendeleev Russian University of Chemical Technology,
9 Miusskaya pl., 125047 Moscow, Russian Federation.
Eꢀmail: traven@muctr.ru
2,3ꢀDihydrofuro[3,2ꢀc]coumarinꢀ3ꢀone reacts with arylhydrazines via two routes. The
corresponding hydrazones are formed from arylhydrazines in alcohol and nitrophenylhydrazines
in acetic acid or toluene. With phenylhydrazine and paraꢀtolylhydrazine in toluene,
2,3ꢀdihydrofuro[3,2ꢀc]coumarinꢀ3ꢀone reacts unusually undergoing dihydrofuran ring openꢀ
ing and the formation of the corresponding 3ꢀ(2ꢀiminoꢀ1ꢀ(2ꢀarylhydrazinyl)ethylidene)ꢀ
chromaneꢀ2,4ꢀdiones. The solvatochromic properties of the synthesized compounds were
studied using electronic absorption spectra and quantum chemical calculations.
Key words: furocoumarinones, hydrazones, tautomerism, isomerization, labeled nitrogen
atom, electronic absorption spectra.
Scheme 1
Derivatives of 2,3ꢀdihydrofuro[3,2ꢀс]coumarinꢀ3ꢀone
(1) are of interest, being analogs of a series of natural
compounds, for example, fercoprolone and pterophylꢀ
lines.1,2 At the same time, coumarin derivatives found
wide use as optically bleaching agents, for the creation of
active media of frequencyꢀcontrolled lasers and lumineꢀ
scent labels. Photosensitive coumarins are promising for
use in electronic photography as photosensitizers and in
the construction of new devices of information recording
and storage.
We have earlier3 studied the reactions of coumarinone
1 with aromatic aldehydes and amines. Compound 1 reꢀ
acts actively to the both methylene and carbonyl group of
the dihydrofuran cycle. It is interesting that the reaction
with substituted anilines at the carbonyl group is accomꢀ
panied by the corresponding tautomeric transformations
with aromatization of the dihydrofuran cycle. Continuing
the systematic investigation of the reactions of coumaꢀ
rinone 1 and its acyclic analog 3ꢀacetylꢀ4ꢀhydroxyꢀ
coumarin4—7 having the purpose to obtain compounds
with valuable spectral properties, we carried out the reacꢀ
tions of compound 1 with arylhydrazines. Arylhydrazines
were used as both hydrochlorides and free bases. These
experiments gave different results.
2a—h (hydrazone)
2a—h (enhydrazine)
2a: R1 = R2 = R3 = R4 = R5 = H
2b: R1 = R2 = R4 = R5 = H, R3 = F
2c: R1 = R5 = Cl, R2 = R3 = R4 = H
2d: R1 = R4 = Cl, R2 = R3 = R5 = H
2e: R1 = R3 = Cl, R2 = R4 = R5 = H
2f: R1 = R2 = R4 = R5 = H, R3 = Me
2g: R1 = R2 = R4 = R5 = H, R3 = NO2
2h: R2 = R4 = R5 = H, R1 = R3 = NO2
Results and Discussion
The results of the reactions of coumarinone 1 (see
Ref. 8) with substituted phenylhydrazine hydrochlorides
and nitrophenylhydrazines taken as free bases are shown
in Scheme 1.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1571—1578, August, 2010.
1066ꢀ5285/10/5908ꢀ1612 © 2010 Springer Science+Business Media, Inc.

Dihydrofuran ring opening in furocoumarinone
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 8, August, 2010
1613
Table 1. Chemical shifts of protons (δ) of the NH and
CH2 groups in the Н NMR spectra (DMSOꢀd6) of
compounds 2
structures of the condensation products of coumarinone 1
with aromatic amines.3
1
As shown in Scheme 2, hydrazones 2 can exist as
Zꢀ and Eꢀisomers, and in the Eꢀisomer the NHꢀproton
and the oxygen atom of the coumarin moiety can be
linked by a hydrogen bond, and should result in
the downfield shift of the NHꢀproton. According to the
1H NMR spectra data, hydrazones 2d, 2a, and 2b are
formed as a mixture of Eꢀ and Zꢀisomers in a ratio of
1 : 2.3, 1 : 1, and 1 : 1, respectively, whereas in compound
2f the content of the Eꢀisomer does not exceed 5%. As
Hydrazone Yield (%)
δ
2
(ratio of
isomers)
NH
CH2
2a (E,Z)
2b (E,Z)
2c (E)
2d (E,Z)
2e (E)
2f (E,Z)
2g (E)
2h
45 (50 : 50)
25 (50 : 50)
41.4
64.1 (30 : 70)
68
50 (5 : 95)
94
46
11.00/9.14 5.50/5.51
10.97/9.13 5.52/5.49
10.60
11.39/8.53 5.58/5.74
11.06 5.54
10.91/9.03 5.51/5.49
5.48
1
already mentioned, in the Н NMR spectra of arylꢀ
hydrazones 2c,e,g, no doubling of the signals from the
CH2 and NH groups is observed, indicating that these
hydrazones exist as a single, most likely, Eꢀisomer.
10.15
—
5.6
—
Scheme 2
Hydrazones 2a—e were synthesized by the reactions
with arylhydrazine hydrochlorides in ethanol with the
addition of sodium acetate. Hydrazone 2f was obtained
under similar conditions, but with triethylamine instead
of sodium acetate. The reactions of coumarinone 1 with
nitrophenylhydrazines taken as bases are accompanied by
the formation of the corresponding hydrazones. The reꢀ
actions of pꢀnitrophenylhydrazine and 2,4ꢀdinitrophenylꢀ
hydrazine with coumarinone 1 afford hydrazones 2g,h.
All hydrazones are formed in good yields, except for comꢀ
pound 2b, which was isolated in 25% yield (Table 1).
As shown in Scheme 1, hydrazones 2a—h can exist in
two tautomeric forms: hydrazone and enhydrazine. For
compounds 2g,c,e,* the presence of the hydrazone form
1
is proved by the Н NMR spectral data: a broadened
single singlet in a weak field at δ 10.15—11.06 indicates
the presence of one NH group and a narrow singlet with
an intensity of two proton units at δ 5.5 corresponds to the
CH2 group. These signals are doubled in the spectra
of compounds 2a,b,d,f: two signals of the NHꢀprotons
with a total integral of one proton unit are detected at
δ 8.53—11.40, whereas two singlets of the CH2 groups
with a total integral value of two proton units are observed
at δ 5.48—5.74. The enhydrazine form of compounds 2
should be observed in the 1H NMR spectra as two broadꢀ
ened downfield signals attributed to the NH group with
an integral of one proton unit each and the singlet of the
methine proton at δ 7—8, while a signal from the CH2
group should be absent. No signals of the enhydrazine
form were observed in the spectral of all compounds 2.
Thus, compounds 2a—h exist as hydrazones. No fiveꢀ
membered ring aromatization resulting in the formation
of the enhydrazine structure is observed. This fact is worth
mentioning, the more so the possibility of this aromatizaꢀ
tion has been observed by us earlier when studying the
The ratio of the Eꢀ and Zꢀisomers in compounds 2a,b
changes after recrystallization from ethanol. For instance,
in compound 2a the content of the Zꢀisomer increases to
90%, whereas in compound 2b it reaches 100%.
The Overhauser nuclear effect was studied to confirm
the assignment of signals of the СН2 and NH groups of
1
the Eꢀ and Zꢀisomers in the Н NMR spectra for comꢀ
pound 2d. This effect was found for the signals with δ 5.74
(СН2) and 8.53 (NH), indicating that these groups in the
Zꢀisomer are spatially close.
The results of PM3 quantum chemical calculations
1
are in agreement with the Н NMR spectral data on the
structure of compounds 2 (Table 2): the Eꢀisomer with
the lowest energy of formation is thermodynamically preꢀ
ferential of two hydrazone forms in compounds 2. The
formation of compounds 2 in the enhydrazine form should
be considered less probable for thermodynamic reasons.
The ratio of Eꢀ and Zꢀisomers in hydrazones 2 deꢀ
pends on the solvent. The 1H NMR spectra of compound
2d in deuterated chloroform and DMSO were detected
1
* We failed to detect the Н NMR spectrum of compound 2h
because of its low solubility (see Experimental).

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Russ.Chem.Bull., Int.Ed., Vol. 59, No. 8, August, 2010
Kondratova et al.
1
for comparison. The character of the H NMR spectrum
in DMSOꢀd6 remains unchanged with time, while a difꢀ
ferent situation is observed in CDCl3. Two signals of the
СН2 groups in CDCl3 are overlapped and have the form
of a single broadened intense singlet at δ 5.44, and the
signals of the NH group as two broadened singlets at
δ 11.36 and 7.02 correspond to the Eꢀ and Zꢀisomers,
respectively. The doubletꢀdoublet signal corresponding
to the 4´ꢀmetaꢀproton of the dichloroꢀsubstituted benꢀ
zene ring is doubled and have the corresponding spinꢀ
in 1 h, the predominant form becomes almost the single:
the content of the Eꢀhydrazone form reaches 99%. It is
most likely that the Eꢀisomer stabilized by the hydrogen
bond prevails in chloroform, while in DMSO two forms exist
due to the distortion of the intramolecular hydrogen bond.
An unexpected reaction route was observed for the
reactions of coumarinone 1 with phenyl and pꢀtolylꢀ
hydrazines taken as bases. For example, when the reacꢀ
tion of compound 1 with phenylhydrazine is carried out
in acetic acid or in toluene, a compound different from
hydrazone 2a was isolated as product. This compound
is the single product, regardless of the fact whether
phenylhydrazone is used in excess or in an equimolar
3
´
spin coupling (SSC) constants JH(3 ),H(4 ) = 8 Hz and
´
´
4´JH(4 ),H(6 ) = 2 Hz at δ 6.83 (E) and 6.7 (Z) with intensiꢀ
´
´
ties of 0.3 and 0.7 proton units. In the spectrum recorded
1
ratio with 1. The study of the Н and 13С NMR spectra
and the mass spectra suggests the structure of the formed
product 3. The 1H NMR spectrum contains four downfield
singlet signals, whereas no upfield signals are observed.
The integral intensity of signals in the spectrum correꢀ
sponds to the presence of 13 protons in the compound
(Fig. 1). The 13С NMR spectrum (Fig. 2) exhibits a signal
at δ 179.99 corresponding to the carbonyl carbon atom in
position 4 of coumarin9 and signals of the carbon atoms of
the phenyl ring. We have previously9 proved the structures
of the Zꢀ and Eꢀketoenamines 4 on the basis of analysis of
Table 2. Enthalpies of formation of Eꢀ
and Zꢀhydrazones 2 and enhydrazines 2
(according to the data of PM3 calculations)
2
H0 /kcal mol–1
f
Enhydrazine 2
Hydrazone 2
E
Z
a
b
c
d
e
f
0.514
–42.56
–10.70
–11.72
–12.10
–8.94
–3.53
–0.624
–47.24 –44.10
–12.90 –11.19
–14.97 –13.50
–15.04 –13.65
–12.97 –10.08
–14.36 –10.36
–18.62 –16.67
1
the Н NMR spectra, quantum chemical calculations,
and Xꢀray diffraction study. As can be seen from Fig. 2,
the chemical shifts of the carbon atoms in the 13С NMR
spectrum of the new compound designated as 3a are rather
close to the signals of the corresponding carbon atoms in
the isomers of ketoenamines 4 shown below.
g
h
–8.91
–14.20
a
7.31
8.88
7.35
7.27
7.26
11.80
7.95
7.65
6.97
7.99
7.62
11.52
11.5
9.47
7.69
12.0
11.0
10.5
10.0
9.5
9.0
8.5
8.85
8.0
7.5
7.0
7.25
6.5 δ
7.15
7.11
7.29
b
11.76
7.34
7.65
7.95
7.98
7.61
7.68
7.69
9.43
11.49
11.5
12.0
11.0
10.5
10.0
9.5
9.0
8.5
8.0
7.5
7.0
6.5
δ
Fig. 1. 1H NMR spectra of compounds 3a (a) and 3b (b).

Dihydrofuran ring opening in furocoumarinone
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 8, August, 2010
1615
128.49(22)
128.97(19.17)
113.86(16.20)
125.60(9)
123.49(10)
121.67(18)
120.43(5)
116.09(7)
133.82(8)
95.32(3)
143.09(15)
165.56(2)
162.23(12)
152.99(6)
179.99(4)
δ
Fig. 2. 13С NMR spectrum of compound 3a.
The 2D COSY spectrum (Fig. 3) demonstrates the
longꢀrange spinꢀspin coupling along the СН(8.88 ppm)—
NH(11.80 ppm) bonds. The spatial closeness of these
groups is also indicated by the experiment on the Overhauser
effect: the intensity of the signal of the NH—Ph group
(δ 11.80) increased upon the suppression of the CH signal
(δ 8.88), and vice versa, the suppression of the signal with
δ 11.80 increases the intensity of the signal with δ 8.88.
Along with the molecular ion peak, the mass spectra
of compound 3а show peaks corresponding to the
[M – CH=NH] and [M – NHNHPh] fragments, which
also confirms the structure proposed.
1
Thus, it can be suggested by the data of H and
13С NMR spectroscopy and mass spectrometry that the
reaction of coumarinone 1 with phenylhydrazine affords
a compound with structure 3a.
8.88
11.8
9.47
δ
11.52
7.0
7.5
8.0
8.5
8.88
9.47
9.0
9.5
10.0
10.5
11.0
11.5
12.0
11.52
11.8
12.0
11.0
10.0
9.0
8.0
7.0 δ
Fig. 3. 1Н—1Н COSY 2D spectrum of compound 3a.

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Kondratova et al.
a
8.88
7.35
7.31
7.27
7.26
11.80
7.95
7.99
7.65
6.97
11.52
9.47
7.62
7.69
12.0
11.5
11.0
10.5
10.0
9.5
9.0
8.5
8.0
7.5
7.0
6.5
δ
1
7.32
7.26
7.35
15
J
J
N—H = 93.4 Гц
b
1
1
6.97
15
J
N—H = 89.7 Гц
15
N—H ≈ 4 Гц
11.81
1
8.87
15
J
N—H ≈ 4 Гц
7.95
7.99
7.65
11.27
11.72
11.74
9.26
9.71
9.73
7.61
7.5
9.25
7.69
11.29
12.0
11.5
11.0
10.5
10.0
9.5
9.0
8.5
8.0
7.0
6.5
δ
Fig. 4. 1H NMR spectra of compounds 3a (a) and 3aꢀ15N (b).
To confirm structure 3a, we carried out the reaction of
compound 1 with labeled phenylhydrazine C6H5NH15NH2,
which was prepared by the diazotization of aniline using
sodium 15Nꢀnitrite. If proposed structure 3a is valid, two
labeled nitrogen atoms should appear in the molecule,
The formation of iminohydrazine 3a is not a single
case of such a route of interaction of compound 1
with arylhydrazines. The reaction of compound 1
with pꢀmethylphenylhydrazine taken as a base in
1
toluene affords compound 3b, whose H NMR spectrum
1
which would reflect the character of the H NMR specꢀ
resembles that of 3a (see Fig. 1).
trum. The spectrum of compound 3aꢀ15N is shown in Fig. 4.
As can be seen from the spectrum (see Fig. 4), upon
the introduction of labeled 15N atoms, the signals with
δ 11.52 and 9.47 are transformed from singlets into two
We believe that the formation of compounds 3 follows
Scheme 3.
It is most probable that the reaction proceeds through
the formation of hydrazone 2. In a control experiment,
hydrazone 2a was dissolved in toluene, and phenylhydrꢀ
azine (1 mol) was added during reflux. Compound 3a was
isolated after reflux for 20 min followed by cooling.
Evidently, hydrazone 2 can react with the second
phenylhydrazine molecule as a nucleophile with fiveꢀ
membered ring opening and the formation of betaine А.
Form А of betaine is in equilibrium with neutral form В
and hydroxy form С. However, it is most likely that
betaine form A undergoes subsequent elimination under
the action of another phenylhydrazine molecule. Easiness
of opening of just the dihydrofuran cycle is determined,
most likely, by the stability of the oxide coumarin moiety
in betaine A. It is known that 4ꢀhydroxycoumarin is
considerably acidic. Its рКа value was experimentally estiꢀ
doublets of doublets with the corresponding firstꢀorder
1
SSC constants J15
= 89.7 Hz and the subsplitting of
N—H
each component of the doublet due to the longꢀrange
interaction 44J15N—H ≈ 4.6 Hz.
When 15N atoms are introduced, the signals of the
CH (δ 8.88) and NH—Ph (δ 11.80) groups in the specꢀ
trum of compound 3aꢀ15N exhibit signal splitting with
3JCH,15NH ≈ 1 Hz and 2JNH,15NH ≈ 1.8 Hz. The longꢀrange
SSC constants were estimated by the double resonance
experiment with compound 3aꢀ15N. The longꢀrange conꢀ
stant 5JCH,NH ≈ 1.8 Hz was established for the signal of CH
5
at δ 8.88, while the constant JNH,CH ≈ 1.8 Hz was found
for the signal of NH—Ph at δ 11.80. The suppression of
one of the signals results in a change, namely, simplificaꢀ
tion of multiplicity of another signal, i.e., the effect simiꢀ
lar to that detected in the 2D COSY spectrum is observed.
The data of mass spectrometry also confirm the forꢀ
mation of compounds 3а and 3aꢀ15N.
1
mated10 as 5.89. We also found aniline by the Н NMR
study of the reaction mixture.
There are literature data for examples of dihydroꢀ
furanone ring opening under the action of arylhydrazine.

Dihydrofuran ring opening in furocoumarinone
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 8, August, 2010
1617
Scheme 3
2 (hydrazone)
The action of pꢀnitrophenylhydrazine on 3ꢀcoumaranone
5 with the intermediate formation of hydrazone 6 and
hydrazinohydrazone 7 affords11,12 ozazone 8 (Scheme 4).
Note that we observed no dihydrofuran ring opening
in the reactions of compound 1 with nitrophenylhydrazines.
The electronic absorption spectra of compounds 2
were recorded in various solvents (Table 3). As can be
seen from Table 3, the absorption maxima differ insignifiꢀ
cantly. The bathochromic shift of the longꢀwavelength
absorption of compounds 2 on going from a polar solvent
(alcohol or DMF) to nonpolar carbon tetrachloride is
due, most likely, to Е/Zꢀisomerization with a possibility
of formation of the intramolecular hydrogen bond of the
NH group with the carbonyl oxygen atom of the lacton
moiety in the Zꢀisomer in the nonpolar solvent and its
cleavage in polar solvents. The isomerization transition is
confirmed by the isosbestic point on going from the polar
Table 3. Longꢀwavelength absorption maxima
(λmax) in the electronic absorption spectra of
compounds 2a—h and 3a,b in various solvents
Comꢀ
pound
λ
max/nm (log ε)
EtOH DMF
CCl4
2a
2b
2c
2d
2e
2f
2g
2h
3a
3b
413 (4.21) 407 (4.13) 407 (4.20)
410 (4.82) 405 (4.83) 404 (4.84)
407 (4.20) 390 (4.23) 395 (4.21)
406 (4.27) 392 (4.39) 393 (4.35)
435 (4.11) 412 (4.10) 418 (4.11)
419 (4.00) 413 (3.92) 413 (3.86)
438 (4.20) 442 (4.07) 438 (4.58)
415 (4.72) 412 (4.64) 416 (4.30)
423 (4.86)
429 (4.62)
—
—
418 (4.86)
427 (4.59)

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Kondratova et al.
Scheme 4
i. EtOH, in cold.
Experimental
1H NMR spectra were recorded on a Bruker WPꢀ200ꢀSY
spectrometer with the working frequency 200 MHz in deuterated
solvents (DMSOꢀd6 and CDCl3) using Me4Si as the internal
standard.
Mass spectra were obtained on a Finnigan MAT SSQꢀ710
mass spectrometer with ionizing radiation energy 70 eV. The
GC—MS spectrum of compound 3a was detected on a
PE SCIEX API165 (ELSD UV254 spectrometer (EI, 70 eV)),
Synergi 2u HydroꢀRP Mercury column 20Ѕ2.0 mm.
Electronic absorption spectra were measured on an APEL
PDꢀ303UV spectrometer. A cell filled with the solvent was used
as a reference cell.
A
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
2
3
4
5
1
The reaction course and individual character of the comꢀ
pounds synthesized were monitored by TLC on Silufol UVꢀ254
plates in the following systems of solvents: (A) chloroform—
acetone (16 : 1); (B) chloroform—acetone (5 : 1); (C) hexane—
acetone (2 : 1).
330
380
430
480
530 λ/nm
Fig. 5. Electronic absorption spectra of compound 2е recorded
at different ratios of CCl4 and DMF: 100 : 0 (1), 75 : 25 (2),
50 : 50 (3), 25 : 75 (4), and 0 : 100 (5).
Quantum chemical calculations were performed using the
HyperChem 6.0 program. Preliminary geometry optimization
was carried out using the molecular mechanics method in the
MM+ variant.
Reactions with arylhydrazine hydrochlorides 2a—e. Coumaꢀ
rinone 1 (0.3 g, 1.5 mmol) was dissolved in ethanol. A solution
of hydrochloride of the corresponding arylhydrazine (2 mmol)
and anhydrous sodium acetate (1.5 g, 2 mmol) in ethanol
(3 mL) was prepared separately. Then a mixture of phenylꢀ
to nonpolar solvent (Fig. 5). As can be seen from the
spectra, the Eꢀ and Zꢀforms only insignificantly differ by
the position of the longꢀwavelength absorption maxima.
No isosbestic points were detected in the absorption
spectra of compounds 3a,b. Therefore, we may conclude
that these compounds exist in one stable form and
undergo no transitions in solution.

Dihydrofuran ring opening in furocoumarinone
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 8, August, 2010
1619
hydrazine with sodium acetate was added dropwise to a boiling
solution of dihydrofurocoumarinone. The reaction mixture was
continued to reflux until a precipitate stopped to form. After the
reaction mixture cooled, hydrazone was filtered off and recrystalꢀ
lized from acetic acid, ethanol, or dioxane.
hydrochloride (2.2 mmol) and triethylamine (0.15 g, 2.2 mmol)
in ethanol (3 mL) was prepared separately. Then a mixture of
pꢀmethylphenylhydrazine with triethylamine was added dropwise
to the boiling solution of dihydrofurocoumarinone. The reaction
mixture was refluxed until a precipitate stopped to form. After
the reaction mixture was cooled down, hydrazone was filtered
off and recrystallized from EtOH. The yield was 0.3 g (50%),
(3E)ꢀ and (3Z)ꢀ4HꢀFuro[3,2ꢀc]chromeneꢀ3,4(2H)ꢀdiones
(2a) 3ꢀ(phenylhydrazones). The yield was 0.11 g (45%),
1
1
m.p. 200ꢀ202 °С (from acetic acid). H NMR (DMSOꢀd6) δ:
m.p. 185—187 °С (from EtOH). H NMR (DMSOꢀd6), δ: 2.22
5.50 (s, 0.5 H, CH2(3E)); 5.51 (s, 0.5 H, CH2(3Z)); 6.74—6.75
(m, 1 H, H(4´)); 6.90—6.94 (m, 1 H, H(2´(3E)), H(6´(3Z)));
7.05—7.30 (m, 3 H, H(6), H(8), H(2´(3Z)), H(6´(3Z)); 7.35—7.65
(m, 2 H, H(3´), H(5´)); 7.65—7.95 (m, 2 H, H(5), H(7)); 9.14
(s, 0.5 H, NH(3Z)); 11.00 (s, 0.5 H, NH(3E)). MS, m/z
(Irel (%)): 292 [M]+ (50), 92 [NHPh]+ (100), 186 [M – NNHPh]+
(42). Found (%): C, 69.79; H, 4.30; N, 9.50. C17H12N2O3.
Calculated (%): C, 69.86; H, 4.14; N, 9.58.
(s, 3 Н, Me); 5.49 (s, 2 H, CH2); 7.03 (s, 4 H, H(2´), H(3´),
H(5´), H(6´)); 7.40—7.53 (m, 2 H, H(6), H(8)); 7.71—7.85
(m, 2 H, H(5), H(7)); 9.03 (s, 1 H, NH). MS, m/z (Irel (%)):
306 [M]+ (43), 201 [M – NHC6H4Me + 1]+ (10), 187
[M – NNHC6H4Me + 1]+ (40), 121 [NNHC6H4Me + 1]+ (50),
106 [NHC6H4Me]+ (100), 91 [C6H4Me]+ (95). Found (%):
C, 71.01; H, 4.62; N, 9.35. C18H14N2O3. Calculated (%):
C, 70.58; H, 4.61; N, 9.15.
(3E)ꢀ and (3Z)ꢀ4HꢀFuro[3,2ꢀc]chromeneꢀ3,4(2H)ꢀdiones
(2b) 3ꢀ[(4´ꢀfluorophenyl)hydrazones]. The yield was 0.17 g (25%),
m.p. 217—219 °С (from acetic acid). H NMR (DMSOꢀd6), δ:
5.49 (s, 1 Н, CH2(3Z)); 5.52 (s, 1 Н, CH2(3E)); 6.98—7.06 (m,
4 H, H(2´), H(3´), H(5´), H(6´)); 7.30—7.65 (m, 2 H, H(6),
H(8)); 7.65—8.00 (m, 2 H, H(5), H(7)); 9.13 (s, 0.5 Н, NH(3Z));
10.97 (s, 0.5 Н, NH(3E)). MS, m/z (Irel (%)): 310 [M]+ (30).
Found (%): C, 65.92; H, 3.60; N, 9.13. C17H11FN2O3. Calculꢀ
ated (%): C, 65.81; H, 3.57; N, 9.03.
Reaction of 2,3ꢀdihydrofuro[3,2ꢀc]coumarinꢀ3ꢀone with
nitrophenylhydrazines. A solution of nitrophenylhydrazine
(2 mmol) in 3 mL of acetic acid (or in 5 mL of toluene). The
precipitate that formed was filtered off. Recrystallization was
carried out from acetic acid or dioxide.
1
(3E)ꢀ4HꢀFuro[3,2ꢀc]chromeneꢀ3,4(2H)ꢀdione 3ꢀ[(4´ꢀnitroꢀ
phenyl)hydrazone] (2g). The yield was 0.48 g (94.5%),
1
m.p. 281—283 °С (from acetic acid). H NMR (DMSOꢀd6), δ:
5.58 (s, 2 Н, CH2); 7.23 (d, 2 H, H(2´), H(6´), J = 8.80 Hz);
7.4—7.6 (m, 2 H, H(6), H(8)); 7.75—7.95 (m, 2 H, H(5), H(7));
8.14 (d, 2 H, H(3´), H(5´)); 10.15 (s, 1 Н, NH). MS, m/z
(Irel (%)): 337 [М + 1]+ (90), 336 [М – 1]+ (20). Found (%):
C, 60.03; H, 3.32; N, 12.50. C17H11N3O5. Calculated (%):
C, 60.54; H, 3.29; N, 12.46.
(3E)ꢀ4HꢀFuro[3,2ꢀc]chromeneꢀ3,4(2H)ꢀdione 3ꢀ[(2´,6´ꢀdiꢀ
chlorophenyl)hydrazone] (2c). The yield was 0.22 g (41.4%),
1
m.p. 176—178 °С (from acetic acid). H NMR (DMSOꢀd6), δ:
5.48 (s, 2 Н, CH2); 6.98—7.06 (m, 1 H, H(4´)); 7.40—7.60 (m,
4 H, H(6), H(8), H(3´), H(5´)); 7.85—7.91 (m, 2 H, H(5),
H(7)); 10.6 (s, 1 Н, NH). MS, m/z (Irel (%)): 360 [M]+ (22).
Found (%): C, 56.57; H, 2.82; N, 7.80. C17H10Cl2N2O3.
Calculated (%): C, 56.53; H, 2.79; N, 7.76.
(3E)ꢀ and (3Z)ꢀ4HꢀFuro[3,2ꢀc]chromeneꢀ3,4(2H)ꢀdiones
(2d) 3ꢀ[(2´,5´ꢀdichlorophenyl)hydrazones]. The yield was 0.35 g
(64.1%), m.p. 254—256 °С (from acetic acid). 1H NMR
(DMSOꢀd6), δ: 5.58 (s, 0.8 H, CH2(3E)); 5.74 (s, 1.2 H, CH2(3Z));
4HꢀFuro[3,2ꢀc]chromeneꢀ3,4(2H)ꢀdione 3ꢀ[(2,4ꢀdinitroꢀ
phenyl)hydrazone] (2h). The yield was 0.26
g (46%),
m.p. 284—286 °С (from DMF). The 1H NMR spectrum was not
detected because of the very low solubility of the substance. MS,
m/z (Irel (%)): 383 [М + 1]+ (100), 384 [М + 2]+ (20). Found (%):
C, 52.99; H, 2.60; N, 14.71. C17H10N4O7. Calculated (%):
C, 53.41; H, 2.64; N, 14.66.
6.78 (dd, 0.38 Н, H(4´(3E)), 3 J4 ,3´ = 8.3 Hz, 4 J4 ,6´ = 1.8 Hz);
Reaction of coumarinone 1 with phenylhydrazine and
pꢀmethylphenylhydrazine. A solution of the corresponding
phenylhydrazine (7.5 mmol) in toluene (3 mL) was added
dropwise to a boiling solution of coumarinone 1 (0.5 g, 2.5 mmol)
in toluene (30 mL). The reaction mixture was refluxed for 15 min.
After cooling of the reaction mixture, the precipitate was filtered
off and recrystallized from acetic acid or toluene.
´
´
´
´
6.88 (dd, 0.62 Н, H(4´(3Z)); 3 J4 ,3´ = 8.3 Hz, 4 J4 ,6´ = 1.8 Hz);
´
´
´
7.20—7.70 (m, 4 H, H(6), H(7), H(8), H(5´)); 7´.70—8.00 (m,
2 H, H(5), H(3´)); 8.53 (s, 0.62 H, NH(3Z)); 11.39 (s, 0.38 H,
NH(3E)). 1H NMR (CDCl3), δ: 5.44 (s, 2 H, CH2); 6.70
(dd, 0.7 Н, H(4´(3E)); 3 J4 ,3´ = 8 Hz, 4 J4 ,6´ = 2 Hz); 6.81 (dd,
´
´
´
´
0.3 Н, H(4´(3Z)); 3 J4 ,3´ = 8 Hz, 4 J4 ,5´ = 2 Hz); 7.02 (s, 0.3 H,
´
´
´
´
NH(3Z)); 7.16—7.46 (m, 4 H, H(6), H(7), H(8), H(5´));
7.66—7.84 (m, 2 H, H(5), H(3´)); 11.36 (s, 0.7 H, NH(3E)).
MS, m/z (Irel (%)): 360 [M]+ (80). Found (%): C, 56.50;
H, 2.83; N, 7.80. C17H10Cl2N2O3. Calculated (%): C, 56.53;
H, 2.79; N, 7.76.
(Z)ꢀ3ꢀ[2ꢀIminoꢀ1ꢀ(2ꢀphenylhydrazinyl)ethylidene]chromaneꢀ
2,4ꢀdione (3a). The yield was 0.38 g (50%), m.p. 299—301 °С
(from acetic acid). 1H NMR (DMSOꢀd6), δ: 6.95—6.99 (m,
1 Н, H(4´)); 7.26—7.35 (m, 6 H, H(6), H(8), H(2´), H(3´),
H(5´), H(6´)); 7.62—7.69 (m, 1 H, H(7)); 7.97 (d, 1 H, H(5)
J5,6 = 8 Hz); 8.88 (s, 1 Н, СН); 9.47 (s, 1 Н, =NН); 11.52 (s,
1 Н, —NН); 11.80 (s, 1 Н, NH—Ph). MS, m/z (Irel (%)): 308
[М + 1]+ (100), 307 [М]+ (90), 279 [M – CH=NH]+ (20), 216
[M – Ph—NH]+ (22). Found (%): C, 66.50; H, 4.35; N, 13.70.
C17H13N3O3. Calculated (%): C, 66.40; H, 4.26; N, 13.67.
(Z)ꢀ3ꢀ[2ꢀIminoꢀ1ꢀ(2ꢀphenylhydrazinyl)ethylidene]chromaneꢀ
2,4ꢀdione (3aꢀ15N). 1H NMR (DMSOꢀd6), δ: 6.95—6.99
(m, 1 Н, H(4´)); 7.26—7.35 (m, 6 H, H(6), H(8), H(2´),
H(3´), H(5´), H(6´)); 7.62—7.69 (m, 1 H, H(7)); 7.97 (d, 1 H,
H(5), J5,6 = 8 Hz); 8.87 (s, 1 Н, СН); 9.47 (dd, 1 Н, =NН,
(3E)ꢀ4HꢀFuro[3,2ꢀc]chromeneꢀ3,4(2H)ꢀdione 3ꢀ[(2´,4´ꢀdiꢀ
chlorophenyl)hydrazone] (2e). The yield was 0.37 g (68%),
1
m.p. 246—248 °С (from acetic acid). H NMR (DMSOꢀd6), δ:
5.54 (s, 2 Н, CH2); 6.96 (dd, 1 H, H(5´), J5 ,6 = 8.6 Hz,
´
´
J5 ,3 = 2.5 Hz); 7.05—7.40 (m, 2 H, H(6), H(8)); 7.40—7.65
´
(m, ´2 H, H(7), H(9)); 7.75—8.00 (m, 2 H, H(5), H(6´)); 11.06
(s, 1 H, NH). MS, m/z (Irel (%)): 360 [M]+ (68). Found (%):
C, 56.51; H, 2.89; N, 7.70. C17H10Cl2N2O3. Calculated (%):
C, 56.53; H, 2.79; N, 7.76.
(3E)ꢀ4HꢀFuro[3,2ꢀc]chromeneꢀ3,4(2H)ꢀdione 3ꢀ[(4´ꢀmethylꢀ
phenyl)hydrazone] (2f). Coumarinone 1 (0.4 g, 2 mol) was
dissolved in ethanol. A solution of pꢀmethylphenylhydrazine
1
1
4
15
15
J
= 89.7 Hz, J
≈ 4.6 Hz); 11.52 (dd, 1 Н, —NН,
N—H
N—H
4
15
15
J
N—H = 93.4 Hz, J
≈ 4.6 Hz); 11.81 (s, 1 Н, NH—Ph).
N—H

1620
Russ.Chem.Bull., Int.Ed., Vol. 59, No. 8, August, 2010
Kondratova et al.
MS, m/z (Irel (%)): 309 [M]+ (15), 201 [M – 15NHNHPh]+
(90), 92 [NHPh]+ (100).
4. V. F. Traven, T. A. Chibisova, A. V. Manaev, Dyes Pigm.,
2003, 58, 41.
(Z)ꢀ3ꢀ[2ꢀIminoꢀ1ꢀ(2ꢀpꢀtolylhydrazinyl)ethylidene]chromaneꢀ
2,4ꢀdione (3b). The yield was 0.12 g (25%), m.p. 260—261 °С
(from acetic acid). 1H NMR (DMSOꢀd6), δ: 2.25 (s, 1 H, Me);
6.95—6.99 (m, 1 Н, H(4´)); 7.26—7.35 (m, 6 H, H(6), H(8),
H(2´), H(3´), H(5´), H(6´)); 7.62—7.69 (m, 1 H, H(7)); 7.97
(д, 1 H, H(5), J5,6 = 8 Hz); 8.85 (s, 1 Н, СН); 9.43 (s, 1 Н,
=NН); 11.49 (s, 1 Н, —NН); 11.76 (s, 1 Н, NH—Ph).
MS, m/z (Irel (%)): 321 [M]+ (5), 320 [M – 1]+ (15), 201
[M – NHNHPhMe – 1]+ (67), 121 [NHNHPhMe]+ (50), 107
[NHPhMe – 1]+ (67), 91 [PhMe]+ (100). Found (%): C, 67.25;
H, 4.80; N, 13.18. C18H15N3O3. Calculated (%): C, 67.28;
H, 4.71; N, 13.08.
5. A. V. Manaev, T. A. Chibisova, V. F. Traven, Izv. Akad.
Nauk, Ser. Khim., 2006, 2144 [Russ. Chem. Bull., Int. Ed.,
2006, 55, 2226].
6. A. V. Manaev, T. A. Chibisova, V. F. Traven, Izv. Akad.
Nauk, Ser. Khim., 2006, 2012 [Russ. Chem. Bull., Int. Ed.,
2006, 55, 2091].
7. V. F. Traven, I. V. Voevodina, A. V. Manaev, N. Ya.
Podkhalyuzina, Khim. Geterotsikl. Soedin., 2007, 513 [Chem.
Heterocycl. Compd. (Engl. Transl.), 2007, 416].
8. M. Trkovnik, N. Zivkovic, M. Kules, R. Djudjic, Org. Prep.
Procedures Int., 1978, 10, 215.
9. V. F. Traven, I. V. Ivanov, V. S. Lebedev, B. G. Milevskii,
T. A. Chibisova, N. P. Solov´eva, V. I. Polshakov, O. N.
Kazheva, G. G. Alexandrov, O. A. Dyachenko, Mendeleev
Commun., 2009, 19, 214.
This work was financially supported by the Russian Foundꢀ
ation for Basic Research (Project No. 08ꢀ03ꢀ90016ꢀBel_a).
10. M. E. Perel´son, Yu. I. Sheinker, Teor. Eksp. Khim., 1966, 4,
185 [Theor. Exp. Chem. (Engl. Transl.), 1966, 4].
11. K. V. Auwers, E. Auffenberg, Ber. Deutsch. Chem. Ges., 1919,
52, 92.
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dron, 1998, 54, 10819.
12. K. V. Auwers, Ber. Deutsch. Chem. Ges., 1917, 50, 1585.
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1908].
Received December 21, 2009;
in revised form April 28, 2010