Indenoxadiazine, indenopyrazole and spiro triazole derivatives from (substituted ylidene)-N-phenylhydrazine carbothioamides

Article abstract of DOI:10.3184/030823407X262472

In a multistep reaction, indeno[2,1-e][1,3,4]oxadiazine-9-one, oxoindeno[1,2-c]- pyrazolecarbothioamide, (thioxo-1,2,4-triazaspiro[4.5] decadienylidene)malononitrile and spiro-(fluorine-9,3′-[1,2,4]triazoline)- 5′-thione derivatives have been formed from a series of (substituted ylidene)-N-phenylhydrazinecarbothioamides 1a-e with (1,3-dioxo-2,3-dihydro-1H- inden-2-ylidene)propanedinitrile, 7,7′,8,8′-tetracyanoquinodimethane and (2,4,7-trinitro-9H-fluoren-9-ylidene)propanedinitrile in aerated pyridine. Rationales of these conversions involving the nucleophilic reactions, condensation, dehydrogenation and oxidation are presented.

Full text of DOI:10.3184/030823407X262472

JOURNAL OF CHEMICAL RESEARCH 2007
NOvEMbER, 629–635
RESEARCH PAPER 629
Indenoxadiazine, indenopyrazole and spiro triazole derivatives from
(substituted ylidene)-N-phenylhydrazine carbothioamides
Alaa A. Hassan* and Hamdy S. Shehata
Chemistry Department, Faculty of Science, El-Minia University, 61519-El-Minia, A. R. Egypt
In a multistep reaction, indeno[2,1-e][1,3,4]oxadiazine-9-one, oxoindeno[1,2-c]- pyrazolecarbothioamide, (thioxo-
1,2,4-triazaspiro[4.5]decadienylidene)malononitrile and spiro-(fluorine-9,3'-[1,2,4]triazoline)-5'-thione derivatives
have been formed from a series of (substituted ylidene)-N-phenylhydrazinecarbothioamides 1a–e with (1,3-dioxo-
2,3-dihydro-1H-inden-2-ylidene)propanedinitrile, 7,7',8,8'-tetracyanoquinodimethane and (2,4,7-trinitro-9H-fluoren-
9-ylidene)propanedinitrile in aerated pyridine. Rationales of these conversions involving the nucleophilic reactions,
condensation, dehydrogenation and oxidation are presented.
Keywords: (substituted ylidene)-N-phenylhydrazinecarbothioamides, indenoxadiazine, indeno-pyrazole and spiro triazole
derivatives
Azomethines constitute
a densely populated class of
S
H
N
compounds readily available by condensation of a carbonyl
compound with ammonia derivative.1, 2 Their widespread
application in organic synthesis is based on the sensitivity of
the C=N double bond towards attacks by nucleophiles and
radicals, and an additional various possibilities offered by
substituents on the nitrogen.2-8
H
N
+2
Ph
C
1
N
C
H
R
O
O
CN
Ph
N
+
O
N
N
N
C
S
HO
O
CN
H
N
H
N
S
N
Ph
C
N
C
H
R
R
H
5a–e(58–67%)
CN
6
(24–24%)
1
O
1
5
and
R
C6H5
a
2
b
c
C6H4-p -OCH3
C6H4-p -Cl
2-Furyl
NO2
d
e
2-Thienyl
NC
NC
CN
Scheme 1
O2N
NO2
CN
Results and discussion
NC
CN
3
This paper focuses on the reactions of thiosemicarbazones
1a–e with p-acceptors 2–4 (Fig. 1) to prepare fused and spiro
heterocyclic compounds. We chose thiosemicarbazones 1a–e
having aryl groups with electron donating and withdrawing
substituents on the benzene ring as well as heterocyclic rings,
in order to examine their reactivity. Solutions of 1a–e (1 mmol
each) in dry pyridine were added to solutions of 2 (2 mmol).
The mixtures were gently warmed to 80–100°C for 4 h with
admission of air. Chromatographic separation of the residue
afforded numerous zones, from which products 5 and 6 could
be isolated (Scheme 1).
The structures of 5a–e have been assigned on the basis
of the elemental analyses and spectral data. The IR spectra
showed strong absorption signals between 1725 and 1720 cm-1
for the carbonyl group, and between 3350–3335 cm-1 for
hydroxyl group as well as 1080–1095 cm-1 for (C–O–C).21
1H NMR spectra showed brood exchangeable signals with
(D2O) between 8.44 and 8.62 ppm due to hydroxyl group.
The 13C NMR decoupling showed signals between 94.26
and 94.96 ppm for aliphatic quaternary carbon atom bearing
a hydroxyl group, between 164.12 and 164.76 for (C-3), and
C=N attached to carbony group and adjacent to chiral carbon
atom (C–9a) at 160.12–160.31 ppm, as well as carbonyl
carbon at 193.42–193.74 ppm. The fragmentation patterns
of the mass spectra of 5a–e characterised by the loss of N2
giving intense (M+-28) ions and loss of RCO giving rise to
the ion m/z = 145 common in the spectra of all compounds
represents 1,3-dioxoindanyl fragments.
4
R
1
a
b
c
d
e
C6H5
C6H4-p-OCH3
C6H4-p-Cl
2-Furyl
2-Thienyl
Fig 1
Aldehyde semicarbazones and thiosemicarbazones (1) are
typical substrates that may undergo ring closure processes
included by an oxidising agent to afford the corresponding
1,2,4-triazole and 1,2,4-oxa- or thiadiazole derivatives.9-16
Selective combination of two or more different electron
acceptors into one molecules leads to a series of new
electron acceptors with unique properties. Such a composite
acceptors are compounds 2-4. (1,3-Dioxo-2,3-dihydro-
1H-inden-2-ylidene)propanedinitrile (2), also referred to
as 2-(dicyanomethylene)indane-1,3-dione readily adds N-
nucleophiles such as secondary aliphatic17 and primary
aromatic amines18 at the cyanomethylene carbon atom which
release of hydrogen cyanide. Compound 2 is also able to
generate imminium ions from the tertiary cyclic amines to
generate a-cyanated amines.19,20
* Correspondent. E-mail: alaahasan2001@yahoo.com
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630 JOURNAL OF CHEMICAL RESEARCH 2007
1
2
gently warmed with admission of air. The residue obtained
from the concentration consisted of a complex mixture
containing a deep blue main component 14a–e and numerous
coloured byproducts each in small quantities. From the gross
composition and spectroscopic evidence the main products
from 1a–e were found to be formed from one molecule of
1a–e and one of 3 in the presence of H2O, by loss of 2H and
one molecule of malononitrile.
+
O
O
CN
CN
CN
H
H
N
C
R
CN
N
S
O
O
C
H
N
H
NH
N
C
H
R
Ph
Ph
N
C
S
The IR spectra (in Kbr) of compounds 14a–e show
characteristic absorptions in the ranges of 3340–3325 (NH)
and 1360–1350 as well as 995–1005 cm-1 to strong vibrational
coupling of C=S and C–N entities. The IR spectra showed
conjugated cyano groups at 2220–2225 cm-1 and carbonyl
A
B
O
O
CN
CN
H
CN
H
1
absorptions at 1700–1710 cm-1. The H NMR of 14b clearly
CN
N
H
S
O
Ph
shows one broad signal at 8.10 for triazoline-NH, the expected
signals for quinonoide-CH observed at d = 6.69–6.82 ppm
and singlet signal at 3.83 ppm due to OCH3 signal besides the
aromatic protons. Signals around 118.22 (CN), 172.28 (CO)
and 183.55 ppm (C=S) in 13C NMR spectrum further support
for the structure assigned to 14b. The molecular ions in EI-mass
spectra of 14a–e confirm the molecular masses and the gross
compositions. Furthermore, the following common features
of the fragmentation patterns also supports the assigned
structures: Loss of Ph–N=C=S giving intense (M+–135)
and loss of RCO giving rise to the ion m/z 168 common in the
spectra of all five compounds. The a priori possible isomeric
structures 15a–d (Scheme 4) were ruled out on the basis of
the lowest field signals in the 13C NMR spectra 14b = 183.55,
14c = 183.46, 14d = 183.74 and 14e = 183.34 ppm) which
clearly support a C=S group and not an isothiourea carbon as
in 15. The formation of products 14a–e may be rationalised
by the mechanism shown in Scheme 5.
It has been reported earlier that (2,4,7-trinitro-9H-fluoren-9-
ylidene)propanedinitrile (4) and other 9-(dicyanomethylene)
nitrofluorene derivatives react with secondary amines with
subsequent substitution of cyano by amino groups to afford
trinitrosubstituted-9-(aminomethylene)fluorenes, while we
have reported the complex reaction of N-arylisoindolines
(being tertiary amines) with 4.30 It has been found that the
addition of N2 of amidines to one of the cyano groups of 4
gives spiro[fluorene-9,4'-(1',2',3',4'-tetrahydropyridine)]-5'-
carbonitriles.31 Recently, it has been reported that 4-substituted
thiosemicarbazides reacted with 4 to form spiro[fluorine-
9,3'-[1,2,4]triazole]derivatives and (4-substituted thiosemi-
carbazone)propanedinitriles.32 This fascinating versatility in the
chemistry of 4 is intriguing and justifies further investigations
of reactions of 4 with thiosemicarbazones 1a–e.
O
C
S
N
N
C
H
R
C
N
N
C
H
R
Ph
N
H
C
D
Scheme 2
Compound
6
shows
a
characteristic yellow colour.
The gross formula C18H10N4OS of 6 was confirmed by the
mass spectrum, which exhibited the molecular ion at m/z
330 (19%). The EI mass spectrum of 6 was characterised
by molecular ion of low intensity and loss of 135 a.m.u.
(representing Ph-N=C=S).
The resulting fragment ions undergo loss of 28 a.m.u (most
likely dinitrogen) followed by loss of 27 (HCN). The IR
spectrum of 6 showed strong absorption at 2225 due to cyano
group, 1715 for the carbonyl group and bands characteristic
of vibrational coupling of the C=S and C–N groups at 1360
and 995 cm-1.22 The 1H NMR spectrum showed a broad
signal at 9.91 ppm for NH attached to phenyl group besides
the aromatic protons. Distinctive signals appeared in the 13C
NMR spectrum of 6 at d = 194.16, 182.84 and 122.16, 118.26
corresponding to C=O, C=S, (C-3), and CN groups repectively.
Next we have to accept that the nucleophilic attack at C=C
of 2 theoretically from four positions of 1 (the three nitrogen
atoms and the sulfur), thus giving rise to adducts A–C
(Scheme 2). C and D could be ruled out on the basis of the
structures formed and the spectroscopic data. These results
indicate that thiosemicarbazones 1a–e react with 2 through
a nucleophilic attack of 1a–e to the C=C double bond of 2,
where the four electron-withdrawing groups (two nitrile
and two carbonyl groups) facilitate this reaction to form the
intermediates A and B. The hydrolysis of A followed by
elimination of substituted aldehyde (RCHO) and loss of a
molecule of HCN as well as H2O afforded the indenopyrazole
6. Elimination a molecule of Ph–N=C=S from the adduct
B, followed by another molecule of malononitrile leads to
the formation of 11 which, in turn, undergoes hydrolysis
followed by dehydrogenation to give 13, compound 13 exerts
its nucleophilic character and attacking C-1 and forming
compounds 5a–e (Scheme 3). Many oxidised products
have been isolated as a result of oxidative processes during
the reaction of benzylidine compounds with p-deficient
compounds.23-25
Pyridine solutions, 1.38 mmol each in
4
and
thiosemicarbazones 1a–e, respectively, were kept at 100°C
for 3 hours with admission of air. Chromatographic separation
of the residue obtained after concentration gave numerous
coloured zones, from which the products 21a–e and 25a–e
could be isolated (Scheme 6).
In addition compounds 22–24 were found in small quantities
in all cases. Structure assignments of compounds 21a–e were
based on spectral data from combustion analysis. For 21a
the gross formula C27H18N6O5S was confirmed by the mass
spectrum which exhibited the molecular ion at m/z 538 (26%),
which also shows fragments for loss of RCO and Ph–N=C=S.
The IR spectrum showed absorption at 3420, 3375 (NH2, NH)
and 1360 as well as 1010 cm-1 to vibrational coupling of C=S
and C–N. Two bands around 1530 and 1335 cm-1 have to be
Much effort has been made so far to develop new
electron acceptors whose structures would enhance the
electrical conductivities of their charge transfer complexes.
Such an attempts was made for the synthesis of 7,7',8,8'-
tetracynoquinodimethane (3). The interest of 3 has focused
on its potential applications on molecular rectifiers26, non-
linear optical materials27 and electron accepting properties.28
Mixture of two-fold molar amounts of 3 with one mole
each of the donors 1a–e in dry pyridine. The mixture was
1
assigned to the nitro group. The H NMR spectrum showed
the presence of the two broad signals centred at 8.88 and
6.52 ppm due to triazole-NH and exocyclic NH2, respectively,
in addition to 15 aromatic protons. Also, the 13C NMR
thiocarbonyl and carbonyl resonances (in DMSO-d6) are
formed at 183.84 and 169.36 ppm, respectively.
PAPER: 07/4857

JOURNAL OF CHEMICAL RESEARCH 2007 631
O
O
CN
CN
HOH
- RCHO
CN
A
CN
H
NH
N
R
H
OH
H
O
C
C
H
N
Ph
C
S
NH
Ph
NH
N
O
S
H
8
7
O
O
CN
-H2O
-HCN
CN
N
N
N
C
OH
NH
Ph
S
N
H
C
S
Ph
N
H
6
9
O
O
CN
-H2C(CN)2
-PhN=C=S
H
N
N
C
H
R
B
CN
HN
N
N
C
H
R
O
11
O
O
10
O
H
C
H
N
H
C
HOH
N
R
N
R
O
OH
H
H
O
O
12
O
O
O
+ 2
- 2H
N
N
N
C
N
R
HO
O
HO
R
13
5
Scheme 3
The isolation of reduction products 23 and 24 derived from 4
posed a special problem. The results of combustion analysis
and spectral data suggested that one of the three nitro groups
in both cases had been reduced, but it was difficult decide on
S
NC
NC
CN
CN
H
N
H
N
Ph
C
N
C
R
H
1
1
the basis of IR and H NMR spectra which one of the three
3
nitro groups had been replaced by an amino group. Acetylation
of 23 gave a product showing a Uv/vis spectrum very similar
to that of 2,7-dinitrofluorenone. On this basis it is suggested
that compound 23 is 4-amino-2,7-dinitro-9-fluorenone. When
the latter was treated with malononitrile in methanol in the
presence of piperidine, a product identical in its m.p., IR and
1H NMR spectra with the sample of 24 as isolated before was
obtained.30 The identity of reduction products 23 and 24 as
well as 2,4,7-trinitro-9-fluorenone 22 derived from 4 was also
demonstrated by comparison with authentic samples.30
NC
N
CN
NC
CN
O
C
O
Ph
N
R
S
N
N
C R
NH
14 (71–83%)
S
Ph
N
H
15
The reaction conditions provide an overall dehydrogenating
and oxygenating environment. The most likely introductory
steps have been outlined in scheme 7. Starting materials 1a–e
form, via a CT-complex followed by a radical ion pair and
the radical pair 1.+ 4-H. as intermediates, the (4-amino-2,7-
dinitro-9H-fluoren-9-ylidene)propanedinitrile 24. Compounds
1a–e may attack a molecule of 24 followed by elimination a
molecule of malononitrile and another of hydrogen to give
spiro compounds 21a–e. On the other hand, 1a–e may react
R
1 and 14
a
b
c
d
e
C6H5
C6H4-p-OCH3
C6H4-p-Cl
2-Furyl
2-Thienyl
Scheme 4
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632 JOURNAL OF CHEMICAL RESEARCH 2007
with another molecule of 4 to give the adduct 27 which, in
turn, may break down to malononitrile, thiadiazoles (25) and
compound 28, being a precursor to 2,4,7-trinitro-9-fluorenone
(22). Reduction product 24 may react similarly to generate 23.
NC
CN
S
H
N
H
N
+ H2O
+ 3
Ph
C
N
C
H
R
NC
NC
Conclusion
1a–e
H
C
N
R
Different interesting fused and spiro heterocyclic structures
have been obtained from the interaction of electron rich
thiosemicarbazones 1a–e with the TCNE-analogous acceptors
(1,3-dioxo-2,3-dihydro-1H-inden-2-ylidene)propanedinitrile
(2), 7,7',8,8'-tetracyanoquinodimethane (3) and (2,4,7-trinitro-
9H-fluoren-9-ylidene)propanedinitrile (4). The reactions and
products presented here provide insight into the spontaneous
reactions between electron donors 1a–e and some electron
acceptors 2–4. The results reported also indicate that
thiosemicarbazones 1a–e react like amines with compounds
2–4 that is by nucleophilic addition–elimination mechanism,
through C=C double bond of 2, 3 and 4.
NH
H
N
Ph
C
S
16
CN
NC
NC
CN
H
H
O
NC
NC
H
OH
N
NH
C
H
R
N
C
R
NC
Ph
NC
H
H
Experimental
NH
H
N
C
S
Ph
N
C
The uncorrected melting points were determined on a Gallenkamp
melting point apparatus; IR spectra were recorded using Kbr disks
on Shimadzu 408 instruments. 1H NMR 500 MHz and 125 MHz
13C NMR spectra were recorded on a bruker DRX500 spectrometer.
Chemical shifts are expressed as d [ppm] with reference to the
tetramethylsilane as an internal standard, s = singlet, m = multiplet,
d = doublet, br = broad. The 13C signals were assigned on the basis
of DEPT 135/90 spectra. The mass spectra (70 ev, electron impact
mode) were recorded on a varian MAT 311 instrument. Combustion
analyses were run at the microanalytical centre, Cairo University,
Egypt. Preparative layer chromatography (PLC) was carried out
using air dried 1.0 mm thick layers of slurry of silica gel (Merck
Pf254) applied on 48 cm wide and 20 cm high glass plates using
toluene/ethyl acetate as developing solvent. Zones were detected by
their colour or by quenching of indicator fluorescence upon exposure
to 254 nm light and extracted out with acetone.
17
S
18
- H2C(CN)2
CN
NC
CN
NC
O
H
N
H
N
Ph
C
H
R
N
C
R
NH
20
H
N
NH O
Ph
S
C
S
Starting materials
- 2H
CN
2-(Substituted benzylidene)-N-phenylhydrazinecarbothioamides 1a–e
1
were prepared according to the literatures.34-38 The H NMR spectra
19
NC
of 2-benzylidene-N-phenyhydrazine-carbothioamide (1a),34 2-(4-
methoxy-benzylidene)-N-phenylhydrazinecarbothioamide (1b),35 2-(4-
chlorobenzylidene)-N-phenylhydrazinecarbothioamide(1c),36 N-pheny-
2-(thiophene-2-ylmethylene)-hydrazinecarbothioamide (1d)37 and 2-
(furan-2-ylmethylene)-N-phenylhydrazinecarbothioamide (1e)38 were
in full accord with the published data. 2-(1,3-Dioxo-2,3-dihydro-1H-
inden-2-ylidene)propanedinitrile (dicyanomethyleneindane-1,3-dione)
(2) was prepared according to Chatterjee.39 7,7',8,8'-Tetra-cyano-
quinodimethane (3) (Aldrich). (2,4,7-Trinitro-9H-fluoren-9-ylidene)
propanedinitrile (4) was prepared from 2,4,7-trinitro-9-fluorenone and
malononitrile according to Mukherjee.40
O
C
Ph
N
N
R
NH
S
14
Scheme 5
NO2
S
H
H
+
Ph N C N N CHR
1
O2N
NO2
R1
NC
CN
4
NH2
N
N
Ph
+
NO2
+
N
H
R
S
O2N
O2N
NO2
Ph
N
C
N
C
R
25 (5–7%)
X
NH O
22, X = O, R1 = NO2 (5-8%)
21 and 25
R
S
1
23
, X = O, R = NH2 (7-10%)
a
b
c
d
e
C6H5
21 (53–56%)
24, X = C(CN)2, R1 = NH2 (8-12%)
C6H4-p-OCH3
C6H4-p-Cl
2-Furyl
2-Thienyl
Scheme 6
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JOURNAL OF CHEMICAL RESEARCH 2007 633
.
1.+ 4.-
. + -H
[CT-complex]
+
1a–e
4
1
4
multistep reduction
.
-H
4
24
NH2
NH2
+ H2O
i) - H2C(CN)2
1a–e + 24
ii) - 2H
O2N
NO2
O2N
NO2
H
C
Ph
N
N
C
O
R
N
R
NC
NH
H
NH OH
CN
S
C
Ph
N
H
21
S
26
NO2
i) - H2C(CN)2
ii) - 25
iii) + H2 f rom 1
1a–e + 4
O2N
NO2
NC
NC
N
C
H
R
NH
H
Ph
N
C
S
27
NO2
NO2
+ 4
4-H. +
O2N
O2N
NO2
NO2
.
29
28
+ O2
NO2
NO2
i) + H. from 1
ii) - H2O
O2N
NO2
O2N
NO2
O
H
O
O
.
22
30
Scheme 7
Reactions of (1,3-dioxo-2,3-dihydro-1H-indene-2-ylidene)propane-
dinitrile (2) with 1a–e
(C-9a), 147.66, 143.35, 134.64 (aryl-C), 131.28, 130.12, 128.86,
128.41, 127.83, (aryl-CH), 93.27 (C-4a). IR (Kbr): 3445 (OH), 1720
(CO), 1635 (C=N), 1095 (C–O–C). MS (m/z,%): 278 (M+, 42), 250
(61), 145 (32), 105 (10), 77 (86). C16H10N2O3 (278.26): Calcd; C,
69.06; H, 3.62; N, 10.07. Found C, 68.79; H, 3.81; N, 9.84.
To a solution of 2 (416 mg, 2.0 mmol) in dry pyridine (10 ml) a
solution of 1a–e (1.0 mmol each) in 10 ml of pyridine was added
dropwise over 5 min at room temperature with stirring and admission
of air. The mixture was warmed gently to 80–100°C and kept at this
temperature with stirring and admission of air for 4 h and concentrated
to dryness. The residue was taken up several times with cold ethanol
(15 ml) at the slurry was concentrated again to remove any residue
pyridine. The solid was then taken up in hot methanol, and solution
was filtrated. This operation was repeated four times. Filtrates and
extracts were combined and concentrated to dryness and the residue
was dissolved in acetone (5 ml). The solution in each case was applied
to 5 PLC-plates and developed with toluene/ethyl acetate (3:1) for the
run with 1a–c and toluene/ethyl acetate (4:1) for the run with 1d,e.
Two intense main zones were extracted. The fastest migrating zone
contained 4a-hydroxy-3-aryl indeno[2,1-e][1,3,4]oxadiazine-9(4aH)-
one (5a–e), whereas the second zone contained 3-cyano-4-oxo-N-
substituted[1,2-c]pyrazole-1(4H)-carbothioamide 6. Extraction of
the zones with acetone and recrystallisation from suitable solvents
afforded compounds 5a–e and 6.
4a-Hydroxy-3-(4-methoxypheny)indeno[2,1-e][1,3,4]oxadiazin-
9(4aH)-one (5b): Orange crystals (0.206 g, 67%), m.p. 241–243°C
1
(methanol). H NMR (DMSO-d6): d = 8.51 (br, 1H, OH), 7.10–8.00
(m, 8H, aryl H), 3.86 (s, 3H, OCH3). 13C NMR: d = 193.42 (C-9),
164.37 (C-3), 160.13 (C-9a), 147.53, 142.16, 130.46 (aryl-C), 130.22,
128.19, 127.78, 126.91 (aryl-CH), 94.46 (C-4a), 56.12 (CH3O).
IR (Kbr): 3450 (OH), 1725 (CO), 1630 (C=N), 1080 (C–O–C). MS
(m/z,%): 308 (M+, 24), 277 (29), 249 (26), 145 (46), 135 (76), 104
(82), 77 (100). C17H12N2O4 (308.29): Calcd; C, 66.23; H, 3.92; N,
9.09. Found: C, 66.46; H, 4.11; N, 8.82.
3-(4-Chloropheny)-4a-hydroxyindeno[2,1-e][1,3,4]oxadiazin-
9(4aH)-one (5c): Yellow crystals (0.161 g, 58%), m.p. 253–255°C
(acetonitrile). 1H NMR (DMSO-d6): d = 8.62 (br, 1H, OH), 7.51–7.82
(m, 8H, aryl H). 13C NMR: d = 193.58 (C-9), 164.78 (C-3), 160.21
(C-9a), 147.39, 142.18, 136.86, 132.26 (aryl-C), 129.34, 128.98,
127.74 (aryl-CH), 94.96(C-4a). IR (Kbr): 3440(OH), 1725 (CO),
1640 (C=N), 1085 (C–O–C). MS (m/z,%): 314/312 (M+, 46), 284
(34), 248 (19), 145 (39), 140 (62), 105 (74), 77 (100). C16H9ClN2O3
(312.71): Calcd; C, 61.45; H, 2.90; Cl, 11.34; N, 8.96. Found: C,
61.67; H, 3.06; Cl, 11.19; N, 9.12.
4a-Hydroxy-3-phenylindeno[2,1-e][1,3,4]oxadiazin-9(4aH)-one
(5a): Pale orange crystals (0.175 g, 63%), m.p. 212–214°C
(acetonitrile). 1H NMR (DMSO-d6): d = 8.44 (br, 1H, OH), 7.46–7.98
(m, 9H, aryl H). 13C NMR: d = 193.66 (C-9), 164.28 (C-3), 160.19
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634 JOURNAL OF CHEMICAL RESEARCH 2007
3-(Furan-2-yl)-4a-hydroxyindeno[2,1-e][1,3,4]oxadiazin-9(4aH)-
one (5d): Yellow crystals (0.161 g, 60%), m.p. 192–194°C (ethanol).
1H NMR (DMSO-d6): d = 8.58 (br, 1H, OH), 6.67–7.80 (m, 7H, aryl
and furan-H). 13C NMR: d = 193.52 (C-9), 164.76 (C-3), 160.31
(C-9a), 147.41, 143.33, 142.26, (aryl and furan-C), 140.18 (furan-
CH-5), 128.26, 127.86 (aryl-CH), 112.74, 112.16 (furan-CH-3,4),
94.84 (C-4a). IR (Kbr): 3435 (OH), 1725 (CO), 1635 (C=N), 1075,
1090 (C–O–C). MS (m/z,%): 268(M+, 36), 240 (17), 145 (56), 105
(83), 95 (100), 67 (64). C14H8N2O4 (268.22): Calcd; C, 62.69; H,
3.01; N, 10.44. Found: C, 62.86; H, 2.89; N, 10.65.
4a-Hydroxy-3-(thiophene-2-yl)indeno[2,1-e][1,3,4]oxadiazine-
9(4aH)-one (5e): Yellow crystals (0.185 g, 65%), m.p. 227–229°C
(ethanol). 1H NMR (DMSO-d6): d = 8.62 (br, 1H, OH), 7.21–7.90 (m,
7H, aryl and thiophen-H). 13C NMR: d = 193.74 (C-9), 164.12 (C-3),
160.23 (C-9a), 147.46, 142.33, 130.19 (thiophenyl and aryl-C), 94.26
(C-4a). IR (Kbr): 3445 (OH), 1720 (CO), 1640 C=N), 1090, 1090
(C–O–C). MS (m/z,%): 284 (M+, 46), 256 (18), 145 (61), 139 (92),
105 (100), 77 (65). C14H8N2O3S (284.29): Calcd; C, 59.15; H, 2.84;
N, 9.85; S, 11.28. Found: C, 58.96; H, 2.97; N, 10.07; S, 11.46.
3-Cyano-4-oxo-N-phenylindeno[1,2-c]pyrazole-1(4H)-
carbothioamide (6): Yellow crystals (0.079–0.092 g, 24–28%),
m.p. 276–278°C (methanol). 1H NMR (DMSO-d6): d = 9.91 (br, 1H,
NH), 6.94–7.78 (m, 9H, aryl H). 13C NMR: d = 194.16 (C=O), 182.84
(C=S), 152.23 (C-8b), 140.29, 137.63, 135.18 (aryl-C), 130.14,
129.54, 128.62, 127.43, 126.87 (aryl-CH), xxxx (C-3), 106.14 (C-
3a). IR (Kbr): 3335 and 3280 (NH), 2225 (CN), (OH), 1715 (CO),
1625 (C=N), 1575 (NH def. and C–N str.), 1360, 995 (C=S, C-N).
MS (m/z,%): 330 (M+, 19), 195 (29), 167 (48), 105 (69), 77 (87), 65
(100). C18H10N4OS (330.36): Calcd; C, 65.44; H, 3.05; N, 16.96; S,
9.71.Found: C, 65.21; H, 2.89; N, 17.14; S, 9.54.
169.88(C-d),140.33,136.24,(aryl-C),132.14,130.16,129.52,128.96,
128.44, 127.84 (aryl-CH), 120.74 (cyclohexadiene-CH-7,9), 118.68
(CN), 76.39 (C-5), 72.89 (C-2). IR (Kbr): 3325 (NH), 2225 (CN),
1700 (CO), 1575 (NH def. and C–N str.), 1350, 1005 (C=S, C–N).
MS (m/z,%): 445/443 (M+, 46), 407 (33), 308 (41), 168 (21), 140
(64), 135 (76), 105 (37), 77 (100), 65 (68). C23H14ClN5OS (443.91):
Calcd; C, 62.23; H, 3.18; Cl, 7.9 N, 15.78; S, 7.22. Found: C, 62.46;
H, 3.27; Cl, 8.19; N, 15.51; S, 7.45.
[1-(Furan-2-carbonyl)-4-phenyl-3-thioxo-1,2,4-triazaspiro
[4.5]deca-6,9-dien-ylidene]malononitrile (14d): blue crystals
(0.295 g, 74%), m.p. 271–273°C (acetonitrile). 1H NMR (DMSO-d6):
d = 8.14 (br, 1H, NH), 7.27–7.85 (m, 8H, furan and aryl-H) 6.72–6.84
(dd, dd, 4H, cyclohexadien-H). 13C NMR: d = 183.12 (C=S), 170.34
(C-d), 168.12 (CO), 147.18, 140.46, (aryl-C and furan-C-2), 144.12
(furan-CH-5), 132.31, 129.43, 128.62 (aryl-CH), 120.62, 120.41,
119.74 (furan-CH and cyclohexadiene-CH-7,9), 118.34 (CN), 75.96
(C-5), 73.23 (C-2). IR (Kbr): 3340 (NH), 2225 (CN), 1705 (CO),
1570 (NH def. and C–N str.), 1350, 1000 (C=S, C–N). MS (m/z,%):
399 (57), 264 (38), 168 (41), 135 (82), 95 (44), 77 (100), 65 (59).
C21H13N5O2S (399.43): Calcd; C, 63.15; H, 3.28; N, 17.53; S, 8.03.
Found: C, 62.94; H, 3.41; N, 17.76; S, 7.86.
[4-Phenyl-1-(thiophen-2-carbonyl)-3-thioxo-1,2,4-
triazaspiro[4.5]deca-6,9-dien-8-ylidene)malononitrile (14e): blue
crystals (0.320 g, 77%), m.p. 301–303°C (acetonitrile). 1H NMR
(DMSO-d6): d = 8.19 (br, 1H, NH), 7.23–7.89 (m, 8H, thiophen
and aryl H), 6.74–6.87 (dd, dd, 4H, cyclohexadien-H).13C NMR:
d = 183.34 (C=S), 179.12 (C-d), 166.86 (CO), 140.65, 137.92
(thiophen-C-2 and aryl-C), 132.78, 132.46, 130.56, 129.16, 129.35,
128.46, 127.86 (cyclohexadien 6,10, thiophen and aryl-CH), 120.26
(cyclohexadiene-CH-7,9), 118.16 (CN), 76.18 (C-5), 72.67 (C-2).
IR (Kbr): 3335 (NH), 2220 (CN), 1710 (CO), 1565 (NH def. and
C–N str.), 1360, 995 (C=S, C–N). MS (m/z,%): 415 (M+, 51), 288
(48), 168 (34), 140 (28), 135 (49), 112 (37), 111 (74), 77 (100), 65
(78). C21H13N5OS2 (415.49): Calcd; C, 60.71; H, 3.15; N, 16.86; S,
15.43. Found: C, 60.94; H, 3.24; N, 17.15; S, 15.66.
Reactions of (2,4,7-trinitro-9H-fluoren-9-ylidene)propanedinitrile
(4) with 1a–e. To 1.38 mmol of 4 in dry pyridine (20 ml) equimolar
amounts of 1a–e in 10 ml of dry pyridine were added with stirring.
The mixture was heated gently without increasing the temperature
about 100°C for 5 hours. The solvent was removed by concentration
and the residue was washed several times with ethanol to remove
residual pyridine. The residue was dissolved in acetone and
separated by preparative layer chromatography using toluene/ethyl
acetate (2:1) as eluent into numerous zones, three of which were
extracted. The fastest migrating zone contained 2,4,7-trinitro-9-
fluorenone (22), the second zone which quenched all indicator
fluorescence upon exposure to 254 nm UV-light contained the
thiadiazoles 25a–e the third zone which is always characterised by
reddish orange colour, contained compounds 21a–e. The material
confirmed to the start was rechromatographed using toluene/ethyl
acetate (1:1) to give another two zones, the faster migrating are of
which contained 4-amino-2,7-dinitro-9-fluorenone (23) whereas the
second zone (deep blue colour) contained (4-amino-2,7-dinitro-9H-
fluorene-9-ylidene)propanedinitrile (24). Extraction of the zones with
acetone and recrystallisation from suitable solvents afforded pure
compounds.
4-Amino-1-benzoyl-2,7-dinitro-4'-phenylspiro(fluoren-9,3'-[1,2,4]
triazolidine)-5'-thione (21a): Reddish orange crystals (0.290 g, 54%),
m.p. 323–325°C (methanol). 1H NMR (DMSO-d6): d = 8.88 (m, 15H,
aryl H), 6.52 (br, 2H, NH2). 13C NMR: d = 183.84 (C=S), 169.23
(CO), 148.19, 147.33 (C-7, C-2), 146.23 (C-4), 140.67, 138.12
(aryl-C), 131.44, 129.72, 129.26, 128.89, 128.38, 127.76, 127.45,
127.21, 126.36, 126.24, 125.83 (aryl-CH), and 78.46 (C-9 = C-3').
(Kbr): 3420, 3375 (NH2, NH), 1710 (CO), 1610 (aryl), 1530, 1335
(NO2), 1360, 1010 (C=S, C–N). MS (m/z,%): 538 (M+, 26), 433 (39),
432 (16), 298 (62), 270 (48), 294 (29), 135 (54), 105 (79), 105 (100),
77 (83), 65 (66). C27H18N6O5S (538.53): Calcd; C, 60.22; H, 3.37; N,
15.61; S, 5.95. Found: C, 60.44; H, 3.51; N, 15.39; S, 6.12.
4-Amino-1-(4-methoxybenzoyl)-2,7-dinitro-4'-phenylspiro(fluoren-
9,3'-[1,2,4]triazolidine)-5'-thione (21b): Reddish orange crystals
(0.318 g, 56%), m.p. 339–341°C (acetonitrile). 1H NMR (DMSO-
d6): d = 8.90 (br, 1H, NH), 7.96–7.12 (m, 14H, aryl H), 6.48 (br,
2H, NH2), 3.87 (S, 3H, OCH3). 13C NMR: d = 183.59 (C=S), 170.14
(CO), 162.66 (aryl-C-OCH3), 148.05, 147.12 (C-7, C-2), 146.57
(C-4), 140.46, 130.17 (aryl-C), 129.88, 128.22, 127.69, 127.23,
127.16, 126.84, 126.41, 126.19, 125.93, 125.36 (aryl-CH), 77.93
(C-9 = C-3'), 55.42 (CH3O). IR (Kbr): 3430, 3360 (NH2, NH), 1705
(CO), 1600 (aryl), 1525, 1340 (NO2), 1360, 990 (C=S, C–N). MS
(m/z,%): 568 (M+, 33), 433 (40), 298 (52), 270 (35), 224 (27), 178
Reaction of 7,7',8,8'-tetracyanoquinodimethane (3) with 1a–e.
solution of 2-(substituted ylidene)-N-phenyhydrazine-carbo-
A
thioamides 1a–e (1.0 mmol) in 10 ml of dry pyridine was added
dropwise to a solution of 3 (2.0 mmol) in 15 ml of dry pyridine with
stirring. The mixture was warmed gently to 60–70°C and kept at this
temperature with stirring and admission of air for 3 h, then warmed
to maximum 100°C for few minutes and concentrated to dryness at
60°C. The residue was washed several times with ethanol to remove
residual pyridine. The residue was dissolved in acetone and separated
by preparative layer chromatography using toluene/ethyl acetate (5:3)
as eluent. Intense blue main zones were extracted and the residue
subjected to repeated plc with the same solvents. Crystallisation from
acetonitrile afforded pure samples of 14a–e, all appearing black,
but giving blue solutions in acetonitrile, ethyl acetate or methanol.
Numerous other mostly coloured zones were observed but it always
contained too little materials to allow for isolation and significant
amounts and had to be discarded as well as the tarry materials
remaining at the start line.
(1-Benzoyl-4-phenyl-3-thioxo-1,2,4-triazaspiro[4.5]deca-6,9-
dien-8-ylidene)malononitrile (14a): blue crystals (0.323 g, 79%),
m.p. 285–287°C (acetonitrile). 1H NMR (DMSO-d6): d = 8.10
(br, 1H, NH), 7.60–7.82 (m, 10H, aryl H), 6.72–6.86 (dd, dd, 4H,
cyclohexadiene-H). 13C NMR: d = 183.67 (C=S), 172.44 (CO),
169.84 (C-d), 140.74, 137.96 (aryl-C), 120.64 (cyclohexadiene-CH-
3',5'), 118.34 (CN), 76.33 (C-5), 71.33 (C-2). IR (Kbr): 3340 (NH),
2225 (CN), 1705 (CO), 1570 (NH def. and C–N str.), 1355, 1005
(C=S, C–N). MS (m/z,%): 409 (M+, l29), 274 (49), 169 (51), 141
(26), 135 (64), 106 (47), 105 (100), 77 (69), 65 (53). C23H15N5OS
(409.46): Calcd; C, 67.47; H, 3.69; N, 17.10; S, 7.83. Found: C,
67.24; H, 3.84; N, 16.88; S, 8.06.
1-[(4-Methoxybenzoyl)-4-phenyl-3-thioxo-1,2,4-triazaspiro
[4.5]deca-6,9-dien-8-ylidene]malononitrile (14b): blue crystals
(0.364 g, 83%), m.p. 310–312°C (acetonitrile). 1H NMR (DMSO-
d6): d = 8.10 (br, 1H, NH), 7.54–7.76 (m, 9H, aryl H), 6.69–6.82
(dd, dd, 4H, cyclohexadien-H), 3.83 (S, 3H, OCH3). 13C NMR:
d = 183.55 (C=S), 172.28 (CO), 170.14 (C-d), 162.18, 140.76, 134.23
(aryl-C), 132.48, 129.82, 128.96, 128.22, 127.93, 127.68, 127.56
(cyclohexadiene-CH-6,10 and aryl-CH), 120.53 (cyclohexadiene-
CH-7,9), 118.22 (CN), 76.22 (C-5), 72.11 (C-2), 56.12 (CH3O).
IR (Kbr): 3330 (NH), 2220 (CN), 1710 (CO), 1565 (NH def. and
C–N str.), 1360, 995 (C=S, C–N). MS (m/z,%): 439 (M+, 27), 408
(12), 304 (42), 168 (56), 140 (29), 136 (87), 135 (100), 105 (61), 77
(42), 65 (59). C24H17N5O2S (439.49): Calcd; C, 65.59; H, 3.90; N,
15.94; S, 7.30.Found: C, 65.36; H, 4.02; N, 16.18; S, 7.55.
[1-(4-Chlorobenzoyl)-4-phenyl-3-thioxo-1,2,4-triazaspiro
[4.5]deca-6,9-dien-ylidene]malononitrile (14c): blue crystals
(0.315 g, 71%), m.p. 318–320°C (acetonitrile). 1H NMR (DMSO-d6):
d = 8.16 (br, 1H, NH), 7.76–7.94 (m, 9H, aryl H), 6.75–6.88 (dd, dd,
4H, cyclohexadien-H). 13C NMR: d = 183.46 (C=S), 172.45 (CO),
PAPER: 07/4857

JOURNAL OF CHEMICAL RESEARCH 2007 635
References
(22), 135 (100), 77 (89), 65 (61). C28H20N6O6S (568.56): Calcd; C,
59.15; H, 3.55; N, 14.78; S, 5.64. Found C, 58.92; H, 3.71; N, 15.03;
S, 5.39.
1
D. Klamann and H. Hagemann Organische Stickstoff-Verbindungen
mitviner C, N, Doppol bindung Thieme: Stuttgart 1990, vol. E146.
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1979; pp 385-443.
4-Amino-1-(4-chlorobenzoyl)-2,7-dinitro-4'-phenylspiro(fluoren-
9,3'-[1,2,4]triazolidine)-5'-thione (21c): blue crystals (0.306 g,
2
1
53%), m.p. 347–49°C (acetonitrile). H NMR (DMSO-d6): d = 8.88
3
4
5
6
7
8
9
D. Enders and U. Reinhold, Tetrahedron Asym. 1997, 8, 1895.
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(br, 1H, NH), 7.97–7.26 (m, 14H, aryl H), 6.54 (br, 2H, NH2), 7.26–
7.51. 13C NMR: d = 183.33 (C=S), 170.41 (CO), 148.21, 147.33
(C-7, C-2), 146.76 (C-4), 140.24, 136.14 (aryl-C), 138.22 (aryl-C-
Cl), 130.14, 129.57, 128.88, 128.33, 127.94, 127.87 127.33, 126.96,
126.57, 126.26 (aryl-CH), 77.91 (C-9 = C-3'). IR (Kbr): 3425, 3370
(NH2, NH), 1720 (CO), 1615 (aryl), 1530, 1335 (NO2), 1355, 1005
(C=S, C–N). MS (m/z,%): 574/572 (M+, 37), 536 (22), 432 (44),
298 (54), 270 (36), 178 (23), 140 (31), 135 (64), 77 (100), 65 (46).
C27H17ClN6O5S (577.48): Calcd; C, 56.60; H, 2.99; Cl, 6.19; N,
14.67; S, 5.60. Found: C, 56.81; H, 3.11; Cl, 5.97; N, 14.43; S, 5.81.
4-Amino-1-(furan-2-carbonyl)-2,7-dinitro-4'-phenylspiro(fluoren-
9,3'-[1,2,4]triazolidine)-5'-thione (21d): Orange crystals (0.280 g,
53%), m.p. 316–318°C (acetonitrile). 1H NMR (DMSO-d6): d = 8.91
(br, 1H, NH), 7.16–7.94 (m, 13H, aryl H), d 6.51 (br, 2H, NH2).
13C NMR: d = 183.26 (C=S), 168.72 (CO), 148.25, 147.41 (C-7,
C-2), 147.10 (furan-C-2), 146.61 (C-4), 144.12 (furan-CH-5), 140.37,
(aryl-C), 129.54, 128.77, 128.14, 127.84, 127.53, 127.15, 126.81,
126.66, 125.74, 125.26 (furan-and aryl-CH), 77.84 (C-9 = C-3').
IR (Kbr): 3430, 3375 (NH2, NH), 1705 (CO), 1600 (aryl), 1525,
1340 (NO2), 1360, 1010 (C=S, C–N). MS (m/z,%): 528 (M+, 28),
433 (17), 433 (17), 298 (36), 270 (27), 178 (42), 135 (76), 95 (64), 77
(100), 65 (78). C25H16N6O6S (528.50): Calcd; C, 56.82; H, 3.05; N,
15.90; S, 6.07. Found: C, 56.61; H, 2.94; N, 16.12; S, 5.87.
4-Amino-2,7-dinitro-4'-phenylspiro(fluoren-9,3'-[1,2,4]
triazolidine)-5'-thione-1-(thiophen-2-carbonyl)(21e):Reddishorange
crystals (0.300 g, 55%), m.p. 334–336°C (acetonitrile). 1H NMR
(DMSO-d6): d = 8.90 (br, 1H, NH), 7.22–7.95 (m, 13H, thiophen
and aryl-H), 6.56 (br, 2H, NH2). 13C NMR: d = 183.42 (C=S),
168.84 (CO), 148.17, 147.29 (C-7, C-2), 146.61 (C-4), 140.38,
137.61 (thiophen and aryl-C), 131.16, 130.36, 129.57, 129.20,
128.67, 128.22, 127.91, 127.44, 127.16, 126.74, 126.23 (thiophen-
and aryl-CH), 77.81 (C-9 = C-3'). IR (Kbr): 3420, 3380 (NH2, NH),
1710 (CO), 1595 (aryl), 1535, 1330 (NO2), 1360, 995 (C=S, C–N).
MS (m/z,%): 544 (M+, 46), 433 (31), 298 (19), 270 (37), 224 (18),
135 (100), 77 (94), 65 (36). C25H16N6O5S2 (544.56): Calcd; C, 55.14;
H, 2.96; N, 15.43; S, 11.78. Found: C, 54.91; H, 3.09; N, 15.65; S,
11.55.
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2,4,7-Trinitro-9-fluorenone (22): M.p. 174–176°C (Lit.33, 175°C)
(5–8%).
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4-Amino-2,7-dinitro-9-fluorenone (23): M.p. 311–313°C (Lit.30,
310–312°C) (7–10%).
(4-Amino-2,7-dinitro-9H-fluoren-9-ylidene)propane dinitrile (24):
M.p. 340–342°C (Lit.30, 340–342°C) (8–15%).
Phenyl-(5-phenyl-3H-[1,3,4]thiadiazole-2-ylidene)amine (25a):
M.p. 137–139°C (Lit.41,42139°C) (6%).
33 F. bell. J. Chem. Soc., 1928, 1990.
34 N.M. Koushik and A.K. Mishra, Indian J. Chem., 2003, 42A, 2762.
35 K.M.M.S. Prakash, L.D. Prabhakar and D.v. Reddy, Analyt. Lett., 1987,
20, 959.
36 R. beckert, M.G. Gruner, I. Seidel and R. Kuban, Monatsh Chemie., 1989,
120, 1125.
37 J. El Mostapha, A. Magali, A.K. Mustayeen and M.b. Gilles, J. Mol.
Struct., 2002, 604, 205.
38 G.M. Lima, J.L. Neto, H. benaldo, H.G.L. Siebald and D.J. Duncalf,
J. Mol. Struct., 2002, 604, 287.
Phenyl-(5-(4-methoxyphenyl)-3-H-[1,3,4]thiadiazole-2-ylidene)
amine (25b): M.p. 141–143°C (Lit.42 141°C) (7%).
Phenyl-(5-(4-chlorophenyl)-3-H-[1,3,4]thiadiazole-2-ylidene)
amine (25c): M.p. 174–176°C (Lit.42 175°C) (5%).
5-(Furan-2-yl)-N-phenyl-1,3,4-thiadiazole-2-amine(24d):M.p.174–
176°C (Lit. 43 175°C) (5%).
N-Phenyl-5-(thiophen-2-yl)-1,3,4-thiadiazole-2-amine (25e): M.p. 174–
176°C (Lit.43 175°C) (6%).
39 S. Chatterjee, J. Chem. Soc. (B), 1969, 725.
40 K. Mukherjee and L. Levasseur, J. Org. Chem., 1965, 30, 644.
41 v.R. Srinivasan and G. Ramachander, Indian J Chem., 1963, 1, 234.
42 M. Dobosz, M. Pitucha and M. Wajec, Acta Pol. Phar., 1996, 53, 31.
43 A. Martvon, S. Stankovsky and M. Uher, Chem. Zvesti., 1980, 34, 118.
Received 28 August 2007; accepted 9 November 2007
Paper 07/4857
doi: 10.3184/030823407X262472
PAPER: 07/4857