Diverse reactivity of α-carbanions derived from alkylidenephosphoranes toward 2-(1λ5-diazynylidene)-1H-indene- 1,3-(2H)dione. General approach to conjugated oxadiazines, pyridazines and spiro[3]pyrazoles

Article abstract of DOI:10.1002/jhet.5570450603

(Chemical Equation Presented) Different types of phosphonium carbanions were applied to 2-diazonio-1,3-dioxo-2,3-dihydro-1H-inden-2-ide (1) in order to synthesize a number of condensed and fused N-heterocycles. When 1 was treated with cyanomethyltriphenylphosphonium chloride oxadiazine-, and pyridazine derivatives were obtained whereas bis-indanylidene derivatives resulted from the reaction of 1 with methyl- and ethyltriphenylphosphonium bromides. On the other hand, a series of substituted and unsubstituted spiro[3′]pyrazoles were obtained from the diazo substrate when reacted with vinyl- and allyltriphenylphosphonium bromides.

Full text of DOI:10.1002/jhet.5570450603

Nov-Dec 2008
1571
Diverse Reactivity of ꢀ-Carbanions Derived from
Alkylidenephosphoranes toward 2-(1ꢀ5-Diazynylidene)-1H-
indene-1,3-(2H)dione. General Approach to Conjugated
Oxadiazines, Pyridazines and Spiro[3]pyrazoles
Wafaa M. Abdou,* Maha D. Khidre, and Rizk E. Khidre
Chemical Industries Division, National Research Centre, Dokki, 12622,
Cairo, Egypt; *wabdou@intouch.com
Received January 7, 2008
O
-
+N
N
2
R
O
R3
N
N
N
N
O
H
N
O
O
N
C
O
O
Br
PPh3
O
Different types of phosphonium carbanions were applied to 2-diazonio-1,3-dioxo-2,3-dihydro-1H-inden-
2-ide (1) in order to synthesize a number of condensed and fused N-heterocycles. When 1 was treated with
cyanomethyltriphenylphosphonium chloride oxadiazine-, and pyridazine derivatives were obtained
whereas bis-indanylidene derivatives resulted from the reaction of 1 with methyl– and ethyltriphenyl-
phosphonium bromides. On the other hand, a series of substituted and unsubstituted spiro[3']pyrazoles
were obtained from the diazo substrate when reacted with vinyl– and allyltriphenylphosphonium bromides.
J. Heterocyclic Chem., 45, 1571 (2008).
INTRODUCTION
to form N-alkylated phosphorus ylides when treated with
diazo compounds according to Scheme 1.
Relatively little work has been reported on the reactions
of phosphorus ylides and the relevant phosphonium salts
on diazo compounds. Our continuing interest in the
reactions of alkylidenephosphoranes and phosphonyl
carbanions with carbon-nitrogen systems such as oximes
[1], hydrazones [2], nitriles [3], anils [3] and azides [4] for
the production of synthetically new nitrogen-heterocycles
led us to investigate the application of the phosphonium
salts 2a-e to 2-(1ꢀ5-diazynylidene)-1H-indene-1,3(2H)-
dione (1, also known as 2-diazonio-1,3-dioxo-2,3-
dihydro-1H-inden-2-ide, and 2-diazo-1,3-indanedione)
(Figure 1).
Scheme 1
Ph3P CHR
Y1 Y2
C
N
N
C
R
N
N
CHY1Y2
Ph3P
R = H, alkyl
Y1 , Y2 = alkyl, aryl
Later on, Schweizer et al [6] elaborated a general
scheme for pyrazoline synthesis from the reaction of
diazo compounds with active ylides as outlined in
Scheme 2.
Scheme 2
CR1R2 X
Ph3P
Y2
O
PPh3 Br
Y1
2a, R1 = H2, R2 = CN, X = Cl
2b, R1, R2 = H3, X = Br
2c, R1 = H2, R2 = Me, X = Br
2d, R1 = H, R = (=CH2), X = Br
2e, R1 = H2, R2 = (-CH=CH2), X = Br
Y1Y2CN2
N
PPh3
- HBr
N
N
N
Y1 , Y2 = alkyl, aryl
O
1
A few additional reports on reactions of this class of
compounds with Wittig reagents have been added since
1980 [7,8]. In effect, reactions of phosphorus ylides with
diazo compounds are not, however, as straightforward as
implied by examples described in Schemes 1 and 2. For
example, N2 was lost when diazoacetophenone was
Figure 1
The diazo function is generally less reactive toward
phosphorus ylides than the carbon-carbon double bond. In
their early work [5], alkylidenephosphoranes were known

1572
W. M. Abdou, M. D. Khidre, and R. E. Khidre
Vol 45
treated with benzoylmethylenetriphenylphosphorane,
thereby 2,6-diphenyl-4-benzylidenepyran was the
reported product [8a].
solution was however, proved by a series of nmr-
experiments.
In this paper, we describe different routes leading to
unexpected products that occurred in the reactions of ꢀ-
diazoketones with phosphonium salts 2a-e. In relation to
this work, new condensed oxadiazines, pyridazines, and
Scheme 3
Ph3P CH2CN Cl
2a
O
O
pyrazoles with substitution patterns required for
a
LiH
N
N
- HCl
biological chemistry program could be synthesized in
moderate to high yields.
+
N N
O
O
1
Ph3P CHCN
3
RESULTS AND DISCUSSION
Route-i
Route-ii
- Ph3PO
When a tetrahydrofuran (THF) solution of 2-diazo-1,3-
indandione (1) was treated with two equivalents of
resonance stabilized ylide, cyanomethylenetriphenyl-
phosphorane (3), prepared in situ from the phosphonium
chloride 2a by addition of an excess of LiH, an immediate
reaction occurred. The reaction mixture was further
heated at the reflux temperature for 36 h to give, after
separation by column chromatography, pyridazine 9 (46%
yield) as the major product, along with oxadiazine 4 (21%
yield) (Scheme 3). Compounds 4 and 9 were obtained in
similar ratio, irrespective if one or two equivalents of 2a
were being used. Obviously, the oxadiazine 4 was formed
via (11 + 1) cycloreaction between 1 and ylide 3, under
the elimination of triphenylphosphine (Scheme 3-route i).
The (11 + 1) cycloreaction was previously reported by
Ege and Gilbert for the formation of 3H-[1,2,4]triazolo-
[4,3-b]indazoles from diazo-azoles with ylides [5d,7]. On
the other hand, the formation of the pyridazine 9 can be
explained through the initial Wittig olefination of 1 to
give the intermediate 7. The latter is longer-lived and
Michael addition reaction of a second ylide species 3 to 7
is undertaken on the methide-carbon. Subsequent
triphenylphosphine and HCN elimination 9 would happen
(Scheme 3, route ii).
- Ph3P
O
9
O
O
13
N
1
4
3
+
N
H
N
N
N
N
H
C
O
CN
NC
C
CN
CHCN
H
4
8
7
PPh3
O
9
Z
N
1
O
9
10
N
1
4
N
13
N
- HCN
- PPh3
6
4
7
5
CN
O
12
11
CN
9
4A, Z = H
5, Z = COPh
6, Z = COMe
In the J-modulated spin-echo 13C nmr spectrum of 4 in
DMSO-d6 one set of signals and a negative phase of the
C3-signal at ꢁc = 101.6 ppm indicates that only tautomer 4
is present. In CDCl3-solution, however, two sets of signals
are obtained, one for tautomer 4 with similar chemical
shifts as in DMSO-d6 and another one, in which the C3-
signal has the character of a down field shifted quaternary
carbon atom (ꢁC = 123.4 ppm). The structure of the
second tautomer was proved to be 4A by a series of
heteronuclear 13C{1H}nOe experiments as follows: The
irradiation of the H3-proton (ꢁH = 5.45 ppm) in DMSO-d6
resulted only in the enhancement of the CN-carbon signal
in the 13C nmr spectra. In CDCl3 solution irradiation of the
most deshielded proton at ꢁH = 13.62 ppm, however,
causes a strong signal enhancement of the C10-signal (ꢁC
= 121.3 ppm) indicating the protonation of N1. Treatment
of 4 with either benzoyl chloride or acetic anhydride in
pyridine gave the expected N-benzoylated and N-
acetylated products 5 and 6 in 76 and 71% yields,
respectively.
Structures 4 and 9 were assigned on the basis of their
1
elemental analyses, ir, H-, 13C nmr, and mass spectral
data [9,10]. The ir spectrum of 4 indicated that 4 is in
equilibrium with 4A since a sharp and strong band
appeared at ꢀ1425 assigned to –N=N stretching band (4),
and a frequency at 3362 cm-1 due to free NH group. The
latter moiety (NH) was also recorded at ꢁH = 13.62 ppm in
1
1
its H nmr (CDCl3) spectrum. The H nmr deshielded the
appearance of the oxadiazine–H(3) singlet (4) at 5.45
ppm, which was expected to give a chemical shift value
not higher than 5 ppm. This deshielding could be
attributed to the influence of the substitution on the
methine-carbon atom in compound 4 at 3-position. Thus,
the substituted electron withdrawing hetero-oxygen atom,
and carbonitrile-group result in an increased acidity of the
corresponding methine-proton (ꢁH = 5.45 ppm). Evidence
for the two different tautomeric structures 4 and 4A in
On the other hand, in the 1H NMR spectrum of
compound 9 the (C3-H)-proton is shifted downfield at
8.48 ppm, which was expected to give a chemical shift
value not higher than ~ 8.15 ppm. This deshielding could
be due to the anisotropy of the heteroatomic system being
effective in a nearly coplanar conformation [11].
Next, we found that treatment of the lithiated methyl-
triphenylphosphonium bromide 2b with diazoketone 1

Nov-Dec 2008
General Approach to Conjugated Oxadiazines, Pyridazines and Spiro[3]pyrazoles
1573
proceeded smoothly, in THF solution at room
temperature. The reddish-orange substance, mp 252-255°,
which was isolated in 84% yield, had the formula
C19H10N4O4, and was shown to be the dimeric product
12a. A similar treatment of 1 with ethyltriphenyl-
phosphonium bromide (2c) gave the parallel methyl
analog 12b. The ir spectra of 12a and 12b exhibited
carbonyl stretching bands in the region 1785-1730 and a
broad NH stretching band at ꢀ ~ 3235 cm-1, while the
C=N stretching frequencies concentrated in the region
1615-1558 cm-1. The mass spectrum of 12a indicated the
presence of ion peaks at 186 (36) [358-172 (C9H4N2O2)]+,
Scheme 4
O
O
LiH
Ph3P CH2R2 Br
Ph3P CHR2
N
N
+
- HBr
2b, R2 = H
2c, R2 = Me
10a,b
1
R2
R3
N
N
N
N
N
1
Ph3P
O
C
NH
N
R2
N
O
O
O
O
4
O
4`
O
(i)
O
+
158 (77) [186-28 (N2)] , and 172 (100) [C9H4N2O2],
- Ph3P
+
which can originate via the cleavage of the molecular ion
peak at m/z (%): 359 (8%) [M + 1]+. Structure 12 was
investigated by nuclear Overhauser effect (nOe)
experiments, which were also useful for the assignment of
the 13C nmr signals.
12a, R2 = R3 = H
1
12b, R2 = Me, R3 = H
12c, R3 = H, R1 = Me
11
The irradiation of the NH proton (12a, ꢁH = 9.58 ppm)
in d6-DMSO solution resulted only in the enhancement of
C(1)- (ꢁC = 153.2 ppm) and the C(4)- (ꢁC = 134.7 ppm)
signals. On the other hand, irradiation of C(1)-proton
(6.82 ppm) produced an equal nOe at the C(4) [ꢁC = 134.7
ppm], and the C(4') [ꢁC = 156.4 ppm] signals in the 13C
nmr spectra too. In compound 12b nOes occurred at the
C(1)-CH3-protons upon irradiation of NH-proton
indicating the protonation of N(2). A possible mechanism
for the formation of compounds 12 is given in Scheme 4.
The diazo compound 1 couples with the alkylidene-
phosphorane 10a (or 10b) to give the ylide intermediate
11, which cannot be isolated since it reacts at once with a
second equivalent of the diazo species 1 with extrusion of
triphenylphosphine. Remarkably, similar observation has
previously been reported [5a,12] for reactions of diazo
compounds or diazonium salts with 2b or 2c.
Treatment of 12a with MeI in the presence of EtONa in
EtOH at room temperature afforded N-methylated
derivative 12c (from MeOH). Furthermore, compound
12a decomposed thermally to give the known [13]
dimeric product 2,2'-ethane-1,2-diylidene bis(1H-indene-
1,3(2H)dione) (13, 67%). Compound 13 could be formed
via reductive dimerization of carbine precursor A
(Scheme 4). The carbine dimer 13 had a mass spectrum
consistent with a parent [M+1]+ ion at m/z 315, and a base
fragment at m/z 157 (100). However, only one isomer of
the dimer 13 was isolated.
O
O
(ii)
ꢀ
12a
CH
C:
- N2
H
O
O
2
A
13
substituted (indanedione) moiety. The ir spectrum of 14a
showed a strong broad band at 3120 cm-1 indicating a
strong intramolecular interaction between amine proton
-
and bromine anion (N- H---Br ). This type of interaction
is supported [15] by the observation that the N-H
stretching vibration band shifted into higher frequencies
(3255 cm -1) when the bromine ion was replaced by
tetraphenylborate anion in 14b. The nmr data for 14b is
consistent with the assigned structure.
On heating 14a with ethanolic sodium ethoxide solution
for 1 h, the corresponding ylide 15 (84%) was obtained
whereas the normal Wittig product 16 (78%) was isolated
on treating 14a with sodium ethoxide solution followed
by benzaldehyde (Scheme 5-ii). On the other hand, when
the reaction of 1 with 2d was performed in the presence of
a base (LiH), or treatment of the initial salt 14a with 10%
NaOH spiro-pyrazoledione (17) was isolated in 74% yield
(Scheme 5-iii).
Even though it has been known [8b,14] that pyrazolines
decompose thermally to give cyclopropanes and/or olefins
with varying product distributions, when the phos-
phonium salt 14a was heated to its melting point
temperature for 30 min., spiro-pyrazole bromide (18) was
isolated in a quantitative yield [6b] (Scheme 5-iv).
However, the uniqueness of isolating 18 that retains the
pyrazoline moiety over the expected products (hydro-
carbons) previously reported [11], provides intermediates
of great synthetic utility, which may undergo a number of
interesting conversions.
Vinyltriphenylphosphonium bromide (2d), on reaction
with 1 in THF solution at reflux temperature for 6 h
yielded only the spiro-pyrazolophosphonium bromide
14a, in excellent yield (87%) (Scheme 5-i). None of the
corresponding 4-substituted salts was obtained.
Undoubtedly, steric factors inhibit the formation of 4-
substituted salt, which would require the phosphonium
moiety of the vinyl salt 2d to be adjacent to the

1574
W. M. Abdou, M. D. Khidre, and R. E. Khidre
Vol 45
Scheme 5
group in 2e is a known process [12]. Furthermore, the
ready elimination of triphenylphosphine from 19 in the
second step occurs through a carbanion mechanism,
driven by the resulting gain of aromaticity.
In summary, the reactions described in the present
paper are in line with those that have already been
reported [5-14] on the chemistry of the diazo compounds
with Wittig reagents. Thus, the results confirm, once
again the concreteness of 1,3-dipolar cycloaddition
reactions between unsaturated phosphorus carbanions and
conjugated diazo-compounds (Schemes 5 and 6).
H
N
3`
O
O
O
Br
PPh3
N
C
+
N
N
(i)
X
PPh3
2d
O
1
14a, X = Br
14b, X = Ph4B
EtONa
EtOH
N
3`
N
N
PhCHO
N
Z
Z
14a
(ii)
PPh3
CH2Ph
- HBr
15
16
EXPERMINTAL
H
N
3`
All melting points are measured on an Electrothermal melting
point apparatus. The IR spectra were recorded on a Perkin Elmer
317 Grating IR spectrophotometer, using KBr pellets. The H
N
NaOH (10%)
- Ph3PO
(iii)
14a
14a
Z
1
and 13C NMR spectra were measured on a Jeol E.C.A-500 MHz
instrument using SiMe4 as an internal reference. The 31P NMR
spectra were recorded with the same instrument, relative to
external H3PO4 (85%). The mass spectra were performed on a
Joel JMS-A X 500 spectrometer. Elemental analyses were
carried out at the Microanalysis Laboratory, Cairo University,
Cairo, Egypt. The appropriate precautions in handling moisture-
sensitive compounds were observed. Solvents were dried by
standard techniques. TLC: Merck 0.2 mm silica gel 60 F154
anal aluminum plates. Column chromatography (CC): silica gel
(Kieselgel 60 mesh, particle size 0.2-0.5 mm; E. Merck,
Darmstadt). The substrate 2-diazonio-1,3-dioxo-2,3-dihydro-1H-
inden-2-ide (1) was prepared according to the reported method
[16].
17
H
N
H
N
Br
Z
(iv)
18
15-18, Z = 2-(indane-1,3-dione)
No reaction was observed when a THF solution of
equivalent amount of 1 and allyltriphenylphosphonium
bromide (2e) was stirred at rt for three days, or heated
under reflux for 20 h. Pyrazoline product 20 (78% yield)
was, however obtained when 2e was allowed to react with
1 in the presence of LiH. The mechanism for the
formation of the spiro[2]pyrazole 20 can be rationalized
through the attack of the azo group on the ꢀ-carbon of the
salt 2e, to generate the intermediate 19 with concomitant
elimination of HBr. Extrusion of triphenylphosphine
results in the formation of the final product 20 (Scheme
6). The electrophilic attack at the central atom of the allyl-
Reaction of ꢀ-Diazoketone 1 with Cyanomethylenetri-
phenylphosphonium Chloride (2a). (A) Preparation of
Compounds 4 and 9: General Method. A solution of 1.52 g of
phosphonium chloride 2a (4.5 mmol) in 15 mL dry tetra-
hydrofuran (THF), was added dropwise to 200 mg slurry of LiH
dispersion (60% in paraffin oil) in 10 mL THF. The reaction
mixture was stirred at rt until all hydrogen evolution had ceased,
and 0.6 g diazoketone 1 (~ 3 mmol) was introduced all at once.
The reaction mixture was heated under reflux for 36 h (TLC).
The product mixture was concentrated to 10 mL, diluted with 30
mL dist H2O, acidified with conc. HCl, and then extracted with
two portions (100 mL) of ethyl acetate. The AcOEt extracts
were combined, back-washed with 100 mL H2O, dried, and the
solvents were evaporated to dryness. The residue was
chromatographed on silica gel with n-hexane/AcOEt as the
eluents, whereupon compounds 4 and 9 were isolated.
Scheme 6
CH3
O
CH2
CH
CH
N
N
HC PPh3
+
Br
H2C PPh3
9-Oxo-1,9-dihydroindeno[2,1-e][1,3,4]oxadiazine-3-carbo-
nitrile (4) was obtained (1:1, v/v) as yellow leaflets (155 mg,
21%), mp 143-145° (CH2Cl2); ir: ꢁ NH 3362 (4A), CN 2223,
9-C=O 1732; C=C, C=N 1598, 1610, -N=N- 1425 cm-1; 1H nmr
(CDCl3): ꢂ 5.45 (s, 1H, 3-CH, 4), 7.42, 7.73 (2d, 3H, H-Ar),
8.13 (dd, J = 2.5, 6.8 Hz, H, peri-H), 13.62 ppm (s, 1H, HN,
4A); 1H nmr (DMSO): 13.62 ppm (s, 1H, HN, 4A) did not
appear; ꢂ 13C nmr (CDCl3): ꢂ 101.6 (3-C, 4), 113.6, 114.4 (-CN,
4 & 4A), 121.3, 126.8, 127.2, 129.6, 131.2, 135.1, 139.3 (C-Ar),
123.4 (3-C, 4A), 146.3 (11-C), 185.3 ppm (9-C=O); 13C nmr
(DMSO): among others, only one recorded data for (3-C) at ꢂ
101.6 ppm; ms: m/z (EI) 211 (42) [M+], 220 (66), 194 (100),
O
2e
1
THF / LiH
- HBr
O
O
O
N
N
Me
N
- PPh3
N
CH
PPh3
Me
O
20
19

Nov-Dec 2008
General Approach to Conjugated Oxadiazines, Pyridazines and Spiro[3]pyrazoles
1575
166 (22), 77 (68). Anal. Calcd. for C11H5N3O2: C, 62.56; H,
2.39; N, 19.9. Found: C, 62.64; H, 2.34; N, 19.97.
Anal. Calcd. for C19H10N4O4: C, 63.69; H, 2.81; N, 15.64.
Found: C, 63.77; H, 2.75; N, 15.59.
9-Oxo-9H-indeno[2,1-c]pyridazine-4-carbonitrile (9) was
obtained (2:8, v/v) as yellow crystals (460 mg, 46%), mp 123-
(1Z)-N,N'-Bis(1,3-dioxo-1,3-dihydro-2H-inden-2-ylidene)-
ethanehydrazonohydrazide (12b) was obtained (1:1, v/v) as
reddish-orange crystals (590 mg, 78% yield), mp 224-225°
(CHCl3); ir: ꢀ NH 3341, 5-, 10, 5', 10'-C=O ~1785, ~1733,
1
125° (MeCN); ir: ꢀ CN 2216, C=O 1728 cm-1. H nmr: ꢁ 7.36,
7.73 (2d, 3H, H-Ar), 8.17 (dd, J = 2.5, 6.8 Hz, 1H, peri-H), 8.48
ppm (s, 1H, 3-H) ; 13C nmr: ꢁ 112.6 (4-C), 127.4 (CN), 121.6,
124.6, 126.7, 129.3, 132.4, 137.6 (C-Ar), 135.4 (11-C), 136.7
(13-C), 156.4 (3-C), 190.3 ppm (9-C=O); ms: m/z (EI): 207 (37)
[M+], 179 (100), 151 (23), 123 (57), 77 (42). Anal. Calcd. for
C12H5N3O: C, 69.56; H, 2.43, N, 20.28. Found: C, 69.66; H,
2.36, N 20.36.
Acylation of 4 with Benzoyl Chloride or Acetic Anhydride.
Preparation of 5 and 6. Benzoyl chloride (or acetic anhydride)
(1.1 mmol) was added to a solution of 0.2 g of 4 (1.0 mmol) in 5
mL of dry pyridine. The reaction mixture was allowed to stand
for 2 days at room temperature. The product mixture, with a
small amount of pyridine hydrochloride present, was poured
onto 40 g of crushed ice. Stirring and scratching afforded a
white solid, which was collected by filtration and washed with
20 mL of ice water, air-dried, and recrystallized from a small
amount of CHCl3 to give a pure sample of 5 (or 6).
1
C=Ns ~ 1558, ~ 1610 cm-1; H nmr: ꢁ 1.22 (s, 3H, H3C.C-1),
6.28 (s, 1H, HC-1), 7.45, 7.74 (2d (m), JH-H = 4.4 Hz, 2 ꢂ 4H, H-
Ar), 9.47 ppm (s, 1H, NH, exchangeable with D2O); 13C nmr: ꢁ
16.74 (CH3.C-1), 124.6 (m), 126.1, 1264, 126.8, 131.6 (m),
133.2 (m), 135.4, 136.3, 143.7, 144.8 (C-Ar, and C'-Ar'), 134.7
(4-C), 152.3 (C-1), 155.6 (C-4'), 183.6, 187.5 ppm (5-, 10, and
5', 10'-C=O); ms: m/z (EI) 373 (< 8) [M + 1+], 372 (11), 371
(10), 357 (18), 200 (48), 172 (100, C9H4N2O2), 158 (77). Anal.
Calcd. for C20H12N4O4: C, 64.51; H, 3.25; N, 15.05. Found: C,
64.57; H, 3.22; N, 15.17.
B. Alkylation of Bis-indenylidene 12a: Preparation of 12c.
To a solution of 0.13 g of sodium (0.006 g-atom) dissolved in 50
mL of EtOH was added 0.5 g of 12a (1.34 mmol). The resulting
yellow mixture was allowed to stir with 0.4 g of MeI (0.003
mol) at rt for 18 h. The solution was precipitated by adding to
300 mL of ether and the solid collected by filtration to give 12c.
N,N'-Bis(1,3-dioxo-1,3-dihydro-2H-inden-2-ylidene)-N-
methylhydrazonoformic hydrazide (12c) was obtained (1:1,
1-Benzoyl-9-oxo-1,9-dihydroindeno[2,1-e][1,3,4]oxadiazine-
3-carbonitrile (5) was obtained in 76% yield, mp 176-178°
(CH3Cl); ir: ꢀ CN 2221, 9-C=O 1729, C=O- benzoyl 1682, C=N
v/v) as yellow crystals (285 mg, 55% yield), mp 186-188°
~
(MeCN); ir:
5-, 10, 5', 10'-C=O ~1784, ~1720, C=Ns ~1600,
1
1595 cm-1. H nmr: ꢁ 7.38-7.93 (m, 6H, H-Ar), 8.13, 8.16 (dd, J
ꢀ
~1618 cm-1; H nmr: ꢁ 3.04 (s, 3H, H3CN), 7.28 (s, 1H, HC-1),
7.37, 7.78 ppm (2d (m), JH-H = 4.4 Hz, 2 ꢂ 4H, H-Ar); 13C nmr: ꢁ
37.3 (CH3N), 124.1 (m), 126.6 (m), 131.3 (m), 133.5, 136.2,
139.7, 141.8 (C-Ar, and C'-Ar'), 131.5 (4-C), 148.3 (1-C), 156.4
(4'-C), 186, 188.9 ppm (5-, 10, and 5', 10'-C=O); ms m/z (EI)
1
= 2.3, 6.4 Hz, 2H, peri-H); 13C nmr: ꢁ 110.5 (10-C), 111.6 (CN),
121.4, 124.3, 126.3, 126.9, 130.3, 131.3, 133.7, 136.5, 139.4 (C-
Ar), 166.7 (C=O, benzoyl), 183.3 ppm (9-C=O); ms: m/z (EI)
315 (37) [M+], 194 (100). Anal. Calcd. for C18H9N3O3: C, 68.57;
H, 2.88; N, 13.33. Found: C, 68.64; H, 2.93; N, 13.27.
+
373 (8) [M + 1] , 372 (17), 371 (9), 357 (28), 200 (48), 172
1-Acetyl-9-oxo-1,9-dihydroindeno[2,1-e][1,3,4]oxadiazine-
3-carbonitrile (6) was obtained in 71% yield, mp 164-166°
(acetone/ether, 1:1 v/v); ir: ꢀ CN 2218, 9-C=O 1723, C(O),
acetyl, 1668, C=N 1598 cm-1; 1H nmr: ꢁ 2.35 (s, 3H, CH3), 7.42,
7.81 (2d, 3H, H-Ar), 8.11 ppm (dd, J = 2.5, 6.8 Hz, 1H, peri-H);
13C nmr: ꢁ 21.6 (CH3), 111.6 (CN), 121.4, 126.4, 128.9, 135.4,
139.6, 140.6 (C-Ar), 132.8 (3-C), 166.4 (C=O, acetyl), 182.3
ppm (9-C=O); ms: m/z (EI) 253 (28) [M+], 206 (39), 194 (100),
166 (21), 123 (57), 77 (48). Anal. Calcd. for C13H7N3O3: C,
61.66; H, 2.79; N, 16.6. Found: C, 61.61; H, 2.84; N, 16.54.
Reaction of 1 with Alkyltriphenylphosphonium Bromides
2b and 2c: A. Preparation of Compounds 12a and 12b. A
THF solution of 4.06 mmol of the appropriate salt 2b or 2c and
0.7 g of the diazoketone 1 (4.06 mmol) was treated with LiH
under the experimental conditions described in the general
procedure for the reaction of 1 and 2a. The reaction mixture was
further stirred, at room temperature for 12 h (with 2b) or 18 h
(with 2c), followed by the usual working up and
chromatography to give 12a or 12b, respectively.
(100, C9H4N2O2), 158 (77). Anal. Calcd. for C20H12N4O4: C,
64.51; H, 3.25; N, 15.05. Found: C, 64.44; H, 3.3; N, 15.09.
C. Thermal Decomposition of 12a: Preparation of
Compound 13. A sample of 0.2 g of 12a was heated to its
melting point temperature for 20-30 min in an oil bath
(temperature maintained 10° over melting point). After cooling,
the solidified decomposition product was washed with 10 mL of
CH2Cl2; and further crystallized from MeOH to give (117 mg,
67% yield) of 2,2'-ethane-1,2-diylidenebis(1H-indene-1,3(2H)-
dione) (13), mp 113-115° (from EtOH) (lit. [13]: mp 115°).
Reaction of 1 with Vinyltriphenylphosphonium Bromide
(2d): A. Preparation of 14a, 14b. A stirred mixture of 1.5 g of
the unsaturated salt 2d (4.1 mmol) and 0.7 g of the diazoketone
1 (4.06 mmol) in 30 mL THF was heated under reflux for 6 h.
After removal of the volatile materials under reduced pressure,
the solid product, so obtained, was crystallized from ethanol to
give yellow crystals of 14a.
(1,3-Dioxo-1,2',3,4'-tetrahydrospiro-[indene-2,3'-pyrazol]-
5'-yl)triphenylphosphonium bromide (14a) (1.9 g, 87% yield),
mp 200-202°; ir: ꢀ NH, hydrogen-bromine bonded 3120, 1-, 3-
N,N'-Bis(1,3-dioxo-1,3-dihydro-2H-inden-2-ylidene)-hydra-
zonoformic hydrazide (12a) was obtained (1:1, v/v) as reddish-
orange crystals (610 mg, 84% yield), mp 252-255° (from
CHCl3); ir: ꢀ NH 3433, 5-, 10, 5', 10'-C=O ~1784, ~1736, C=Ns
1
C=O 1782, 1724, N=C 1595, C-P 1115, phenyl 685 cm-1; H
3
nmr: ꢁ 2.03 (d, JP-H = 4.4 Hz, 2H, 4'-CH2), 7.40-8.27 (m, 19H,
2
H-Ph), 9.45 ppm (s, 1H, HN); 13C nmr: ꢁ 28.6 (d, JP-C = 33.5
1
1588, 1608 cm-1; H nmr: ꢁ 6.82 (s, 1H, 1-CH), 7.45, 7.74 (2d
Hz, 4'-CH2), 70.4 (d, 3JP-C = 8.2 Hz, 3'-C), 26.3 (m), 127.4, 128.7
(m), 128.9, 130.6 (m), 132.5, 133,3, 135.8, 143.1 (C-Ar), 144.4
(m), JH-H = 4.4 Hz, 2 ꢂ 4H, H-Ar), 9.58 ppm (s, 1H, NH,
exchangeable with D2O); 13C nmr: ꢁ 124.2, 124.4, 124.6, 124.9,
126.6 (m), 131.2-131.6 (m), 135.4, 136.2, 147.1, 147.8 (C-Ar,
and C'-Ar'), 134.7 (4-C), 153.2 (1-C), 156.4 (4'-C), 178.6, 184.7
ppm (5-, 10, and 5', 10'-C=O); ms: m/z (EI) 359 (8) [M + 1] +,
358 (11), 357 (10), 186 (36), 172 (100, C9H4N2O2), 158 (77).
1
(d, JP-C = 196.4 Hz, 5'-C-P), 178.4, 188.9 ppm (1-, 3-C=O); 13P
nmr: ꢁ 16.3 ppm; ms: m/z (EI) 540 (14) [M - 1]+, 460 (100), 198
(63), 164 (34), 262 (66). Anal. Calcd. for C29H22BrN2O2P: C,
64.34; H, 4.1; Br, 14.76; N, 5.17; P 5.72. Found: C, 64.41; H,
4.17; Br, 14.68; N, 5.11; P 5.61.

1576
W. M. Abdou, M. D. Khidre, and R. E. Khidre
Vol 45
A sample of pyrazolin-5'-yl-triphenylphosphonium bromide
Compound 17 (78% yield, based on 1) could be directly
obtained from the reaction of 1 with 2d, in the presence of LiH,
using the same amounts, and the same procedure applied to the
reaction of 1 with 2a.
E. Thermal Decomposition of 14: Preparation of 18. A
sample of 0.5 g of 14a was heated to its melting point
temperature for 30 min in an oil bath (temperature maintained
10° over melting point). The residue was extracted with boiling
petroleum ether (br 60-80°), which afforded triphenylphosphine
and triphenylphosphine oxide, on cooling. Crystallization of the
insoluble portion from benzene yielded straw yellow needles of
18.
14a was added to a solution of a molar amount of sodium tetra-
phenylborate in CH2Cl2. The solution was boiled for 15 min and
filtered. The filtrate was concentrated while adding AcOEt to
precipitate the borate salt 14b, mp 218-220°; ir: NH 3255, 1-, 3-
C=O 1782, 1724, N=C 1590, C-P 1115, phenyl 675 cm-1.
B. Reaction of 14a with Ethanolic Sodium Ethoxide.
Preparation of 15. A sample of 0.5 g of the salt 14a was added
to a solution of 0.2 g sodium in 50 mL of ethanol. The mixture
was allowed to reflux for 1 h. After cooling, the crude mixture
was concentrated, poured into 100 mL of dist H2O, acidified
with conc HCl and extracted with CHCl3 (2ꢀ100 mL). The
combined organic extracts were washed with 50 mL of dist H2O
and dried. After evaporation of the solvent under reduced
pressure, the residue was crystallized from MeCN to give 15.
5'(Triphenyl-phosphoranylidene)-4',5'-dihydrospiro[indene-
1,3-Dioxo-1,1',2',3-tetrahydrospiro[indene-2,3'-pyrazol[5]-
ylium] bromide (18) (176 mg, 67% yield), mp 175-177°; ir:
1-, 3-C=O 1780, 1723 cm-1; 1H nmr: ꢀ 6.54 (d, JH-H = 2.4 Hz,
~
ꢀ
1H, 4'-HC), 7.46, 7.78 (2d, JHH = 4.8 Hz, 4H, H-Ar), 9.98 ppm
(br, 2H, NHs); ms: m/z (EI): 279 (77) [M – 1] +, 278 (28), 198
(100), 172, (40), 77 (55). Anal. Calcd. for C11H7BrN2O2: C,
47.34; H, 2.53; Br, 28.63; N, 10.04. Found: C, 47.24; H, 2.51;
Br, 28.55; N, 10.12.
Reaction of 1 with Allyltriphenylphosphonium Bromide
(2e): Preparation of Compound 20. A THF solution of 1.57 of
the phosphonium salt 2e (4.1 mmol) and 0.7 g of the diazo-
ketone 1 (4.06 mmol) was treated with LiH under the
experimental conditions described in the general procedure for
the reaction of 1 and 2. The reaction mixture was heated at the
reflux temperature for 10 h, followed by the usual working up,
and chromatography to give compound 20.
5'-Methylspiro[indene-2,3'-pyrazole]-1,3-dione (20) (244
mg, 78% yield), mp 190-192° (benzene); ir: ꢂ 1-, 3-C=O 1786,
1743, N=N 1436 cm-1; 1H nmr: ꢁ 2.15 (s, 3H, -CH3), 6.71 (s, 1H,
4'-CH), 7.75, 7.88 ppm (2d, JHH = 4.4 Hz, 4H, H-Ph); 13C nmr: ꢁ
13.2 (-CH3), 80.6 (3'-C, spiro), 118.7 (4'-C), 124.3, 123.6, 124.7,
128.7, 135.8, 143.1 (C-Ar), 168.4 (5'-C), 190.3, 196.4 ppm (1-,
3-C=O); ms: m/z (EI) 212 (100) [M +], 197 (85), 169 (33), 141
(16), 77 (32). Anal. Calcd. for C12H8N2O2: C, 67.92; H, 3.8; N,
13.2. Found: C, 67.98; H, 3.75; N, 13.27.
2,3'-pyrazole]-1,3-dione (15) (357 mg, 84% yield), mp 200-
~
202°; ir:
1782, 1724 (1-, 3-C=O), 1429 (N=N), 1117 (C-P),
1
ꢀ
3
682 (phenyl) cm-1; H nmr: ꢁ 2.11 (d, JP-H = 6.4 Hz, 2H, 4'-
CH2), 7.39-8.23 ppm (m, 19H, H-Ph); 13C nmr: ꢁ 28.6 (d, 2JP-C
33.5 Hz, 4'-CH2), 103.7 (d, JP-C = 11.2 Hz, 3'-C), 126.3 (m),
127.4, 128.7 (m), 128.9, 130.6 (m), 132.5, 133,3, 135.8, 143.1
=
3
1
(C-Ar), 168.4 (d, JP-C = 149 Hz, 5'-C-P), 186.4, 189.4, (1-, 3-
C=O); 31P nmr: ꢁ 19.6 ppm; ms: m/z (EI): 461 (90) [M + 1] +,
262 (66), 198 (100). Anal. Calcd. for C29H21N2O2P: C, 75.64; H,
4.6; N, 6.08; P, 6.73. Found: C, 75.71; H, 4.67; N, 6.11; P 6.82.
C. Preparation of Compound 16. To a mixture of 0.5 g of
the salt 14a (1.08 mmol) and 0.12 g of benzaldehyde (1.1 mmol)
in 15 mL of ethanol was slowly added 10 mL of an ethanolic
sodium ethoxide solution. The mixture was allowed to reflux
for 3 h (TLC). After the solvent was evaporated to dryness, the
residue was extracted with boiling petroleum ether (br 60-80°) to
separate triphenylphosphine oxide, on cooling. Crystallization of
the insoluble portion from MeCN afforded 16.
5'-Benzylspiro-[indene-2,3'-pyrazole]-1,3-dione (16) (210
mg, 78% yield), mp 172-174°; ir: ꢂ 1-, 3-C=O 1782, 1724, N=N
1
1429 cm-1; H nmr: ꢁ 2.34 (s, 2H, -CH2), 6.36 (s, 1H, 4'-CH),
7.45-8.15 ppm (m, 9H, H-Ph); 13C nmr: ꢁ 39.2 (-CH2), 78.6 (3'-
C, spiro), 110.7 (4'-C), 124.4, 126.3, 127.4, 128.7, 128.9, 130.6,
132.5, 133,3, 135.8, 143.1 (C-Ar), 152 (5'-C), 188.2, 190.4 ppm
(1-, 3-C=O); ms: m/z (EI) 288 (100) [M +], 260 (18), 232 (24),
204 (37), 197 (22). Anal. Calcd. for C18H12N2O2: C, 74.99; H,
4.19; N, 9.72. Found: C, 74.93; H, 4.23; N, 9.81.
D. Aqueous Basic Hydrolysis of 14. Preparation of
Compound 17. A sample (0.5 g) of the salt 14a (or 15) was
allowed to stir with 20 mL of NaOH (aqu. 10%) by warming the
mixture to ~ 80° for 3 h. The product mixture was diluted with
an equal amount of water, and extracted with ethyl acetate,
washed, dried, and the solvent was evaporated to dryness. The
residue was extracted with boiling petroleum ether (br 60-80°) to
give triphenylphosphine oxide, on cooling. Crystallization of the
insoluble portion from CH2Cl2 afforded 17.
No reaction was observed in a parallel experiment when the
above reaction (1 + 2e) proceeded in absence of the base.
REFERENCES
[1] For a recent discussion and literature references, see: [1a]
Abdou, W. M.; Sediek, A. A.; Khidre, M. D. Monatsh. Chem. 2008, 139,
in press; [1b] Abdou, W. M.; Salem, M. A. I.; Barghash, R. F. Arkivoc
2007, 15, 45; [1c] Abdou, W. M.; Barghash, R. F. Trends in Heterocycl.
Chem. 2005, 10, 57; [1d] Abdou, W. M.; Salem, M. A. I.; Sediek, A. A.
Monatsh. Chem. 2003, 134, 1373; [1e] Abdou, W. M.; Salem, M. A. I.;
Sediek, A. A. Bull. Chem. Soc. Jpn. 2002, 75, 2481; [1f] Abdou, W. M.
Phosphorus, Sulfur, Silicon, and Related Elements 2002, 177, 325; [1g]
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[2] Abdou, W. M. Synthetic Commun. 1997, 27, 3599.
2',4'-Dihydrospiro-[indene-2,3'-pyrazole]-1,3-dione (17):
(136 mg, 74% yield, based on 14a), mp 126-128°; ir: ꢂ NH
3325, 1-, 3-C=O 1782, 1724, C=N 1600 cm-1; 1H nmr: ꢁ 2.77 (d,
JH-H = 2.1 Hz, 2H, 4'-CH2), 6.68 (t, JH-H = 2.1 Hz, 1 H, 5'-CH),
7.45, 7.78 (2d, JH-H = 6.6 Hz, 4H, H-Ar), 9.55 ppm (s, 1H, NH
exchangeable with D2O); 13C nmr: ꢁ 34.2 (4'-CH2), 74.6 (3'-C),
124.8, 126.9, 133.8, 142.4 (C-Ar), 141.6 (5'-CH), 194, 200.3
[3a] Abdou, W. M.; Salem, M. A. I.; Barghash, R. F. Phosphorus,
Sulfur, Silicon 2003, 178, 125; [3b] Abdou, W. M.; Salem, M. A. I.;
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ppm (1-, 3-C=O); ms: m/z (EI) 198 (100) [M -2] , 170 (25),
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