Reactions of cyclic oxalyl compounds, 43 [1]: Synthesis and thermolysis of fused 1-arylaminopyrrolones

Article abstract of DOI:10.1002/jhet.5570380508

Fused N-(di)arylamino-pyrrol-2,3-diones 1 are reacted with diphenylketene, thiosemicarbazide or 1,2-diaminobenzene to afford the 3-diphenylmethylene pyrrolones 2, the thiosemicarbazones 4 or the quinoxaline derivatives 5 as well as 6, respectively. Thermolysis of 2b,c,e,f,6b and the pyrrolo-quinoxaline 8 afford the corresponding N-deaminated products 3, 7 and 9. Rearrangements into diazapropellanes following a thermally initiated Fischer - indolization as originally expected do not occur.

Full text of DOI:10.1002/jhet.5570380508

Reactions of Cyclic Oxalyl Compounds, 43 [1]:
Synthesis and Thermolysis of Fused 1-Arylaminopyrrolones
Gert Kollenz* and Ralph Theuer
1055
Sep-Oct 2001
Institut fuer Chemie, Organic Chemistry Division,
Karl-Franzens Universitaet Graz, Heinrichstrasse 29, A-8010 Graz/Austria
Karl Peters and Eva-Maria Peters
Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70506 Stuttgart, Germany
Received December 4, 2000
Fused N-(di)arylamino-pyrrol-2,3-diones 1 are reacted with diphenylketene, thiosemicarbazide or
1,2-diaminobenzene to afford the 3-diphenylmethylene pyrrolones 2, the thiosemicarbazones 4 or the
quinoxaline derivatives 5 as well as 6, respectively. Thermolysis of 2b,c,e,f,6b and the pyrrolo-quinoxaline
8 afford the corresponding N-deaminated products 3, 7 and 9. Rearrangements into diazapropellanes
following a thermally initiated Fischer – indolization as originally expected do not occur.
J. Heterocyclic Chem., 38, 1055 (2001).
1-(Di)arylaminopyrrol-2,3-diones were found to
reactions of the corresponding hydrazones and
oxalylchloride [7], with diphenylketene [10,11] converted
rearrange into the corresponding pyrrolo[2,3-b]indoles via a
Fischer-indolization process by simple heating in the solid
state or in inert solvents [2,3,4,5]. The rearrangement is
nicely indicated by a change of colour from deep red into
bright yellow. Consequently, applying 4,5-bridged pyrrol-
2,3-diones a simple and versatile approach to diaza-
[n.3.3]propellanes became feasible [6,7] (see Chart). The
reaction mechanism of those conversions has been thor-
oughly investigated with aid of isotopic labeling, a) making
evident an intramolecular course of these rearrangements
[8], and b), from KIE-measurements a sigmatropic [3.3]
shift as required for a true Fischer-indole synthesis could be
established as the rate determining step [9].
In order to prove the scope and limitations of these
indolization reactions we now wanted to investigate the
influence of changes within the 2,3-dioxo moiety of the
educts 1 on the overall outcome of the thermolysis reactions,
in particular, if the ability to undergo the indolization
process towards diazapropellanes was still alive.
the carbonyl on C-3 into a (Ph) C=C - moiety thus
2
affording the 3-diphenylmethylene- pyrrol-2-ones 2
(Scheme 1). b) Reaction of pyrroldiones 1 and thio-
semicarbazide resulted in the introduction of a C=N-group
at C-3 with formation of the thiosemicarbazones 4
(Scheme 2). c) 1,2-Diaminobenzene and 1 combined to
give the 2-quinoxalinone derivatives 5 as well as the
pyrrolo[2,3-b]quinoxalines 6 (Scheme 3). d) Attempts to
convert the C=O groups of 1 into one or even two C=S
moieties by treating with Lawesson reagent [12] did not
follow the expected route, but from these novel
experiments, deeply coloured dyes of the isoindigoide type
were recently obtained [13].
Preparation of Functionalized Fused Pyrrol-2,3-diones 2,
4, 5 and 6.
a) The fused 3-diphenylmethylene-pyrrol-2-ones 2 are
obtained in 54-90% yield from heating diphenylketene
and the corresponding pyrrol-2,3-diones 1 [7] to
60 - 110 °C without any solvent until the evolution of
carbon dioxide is complete. The reaction proceeds via a
This should be achieved by converting one or both of the
carbonyl groups into different functionalities: a) reacting the
pyrroldiones 1, easily prepared from cyclocondensation

1056
G. Kollenz, R. Theuer, K. Peters and E.-M. Peters
Vol. 38
[2 + 2] cycloaddition/cycloreversion process as usually
observed and expected from ketene-carbonyl
interactions in general [14,15,16] and also found from
the reaction of isatin and dichloroketene [17]. In
particular, similar to 1, monocyclic furan- as well as
pyrrol-2,3-diones and diphenylketene also afford the
corresponding 3-diphenylmethylene products, under
both photochemical and thermal conditions [18].
Therefore, besides correct elemental analyses (see
Experimental), structural confirmation of the fused
pyrrolones 2 was easily obtained by comparison of their
system represents the basic skeleton for several
molecules with cytotoxic, antitumor and antiinflamma-
tory [19-21] as well as antibiotic and antifungal
activities [22,23].
b) The orange-red coloured thiosemicarbazone deriva-
+
tives 4 are obtained in 52-81% yields from the H
(ether/hydrochloric acid) catalyzed reaction of the corre-
sponding fused diones 1 and thiosemicarbazide in boiling
ethanol as the result of a simple condensation of a carbonyl
group and the NH -functionality.
2
Structural analogues of 4 [4], in particular thiosemi-
carbazones of several isatins have found strong interest due
to their distinct biological (antiviral, bacteriostatic) activities
[24-29]. Comparison of the IR-data of 4 (C=O absorptions at
13
ir - as well as C- nmr data (selected example 2d) with
those of very close related derivatives reported in
reference [18]. Characteristic ir-absorptions at
-1
-1
1705-1715 (lactam carbonyls) and 1585-1590 cm
1695-1715 cm ) among themselves and with those of
-1
(C=C) and loss of absorptions at 1765 cm (for educts 1
several analogues reported in [4,24,29], together with correct
results of their elemental analyses (see Experimental),
evidence their molecular skeleton. Further confirmation also
[7]) indicate a chemical transformation at C-3. The
13
C-nmr signals of 2d appear at 168.5 (C-2) 117.5 (C-4)
1
13
148.0, 145.5 (C-5, C-6, interchangeable), the signal for
C-3 in the educt 1d (expected within 172-175 ppm, see
[7,18]) is missing as with further compounds 2 (details
see Experimental). The 3-methylene-pyrrol-2-one ring
came from H - and C nmr data (see Experimental).
c) Reaction of 1 and 1,2-diaminobenzene in general was
expected to afford fused pyrrolo[2,3-b]quinoxaline deriva-
tives as found with isatines [30] and analogues [31] as well

Sep-Oct 2001
Reactions of Cyclic Oxalyl Compounds
1057
as monocyclic pyrrol-2,3-diones [32,33]. Actually, as
examples, from 1b,f the corresponding target molecules
6b,f could be obtained in rather divergent yields of 60%
(6b) and 21% (6f) by acid catalyzed heating of the
reactants in boiling aequous ethanol.
Molecule I
However, formation of 6 could also be achieved via
quinoxalinone derivatives 5 following a similar procedure
observed with non-fused pyrrol-2,3-diones [31]
(see Scheme 3). The reactants 1 and 1,2-diaminobenzene
(molar ratio 1:2) were dissolved in a suitable amount of
dichloromethane, a few drops of etheral hydrochloric acid
were added and the reaction mixture stirred at room
temperature for up to 48 hours. Evaporation and triturating
with ether afforded 5a,b,c,f in yields from 16-75%,
depending on the specific nature of 1. Quinoxalinones 5b,f
(5b via the tautomeric form 5I) then were converted into the
desired fused compounds 6b,f by treating with oxalyl chlo-
ride and subsequent refluxing in aequous ethanol. In case of
5b, formation of an additional rather unstable intermediate
was observed, that analytical and ir-spectroscopic data (see
Experimental) indicate, should be the tautomeric form 5I. It
decomposes in solution, but by immediate heating in
aequous ethanol (80%) it is also converted into 6b.
Molecule II
Elucidation of the molecular skeletons of the quinoxa-
linone derivatives 5 was based upon the X-ray crystal
structure determination of 5b (Figure 1):
-
5b crystallizes triclinic within the space group Pi (Nr.2)
and with a = 1526.7(6), b = 1548.2(6), c = 1027.7(4) pm,
α = 91.71(4)°, ß = 100.70(4)° and γ = 87.36(4)°. The unit cell
contains Z = 4 molecules with Z = 2 asymmetric units (see
Table 1). Table 2 shows bond lengths and angles, the
numbering of atoms can be found from Figure 1. The cyclo-
hexene ring represents the boat conformation while the
Figure 1

1058
G. Kollenz, R. Theuer, K. Peters and E.-M. Peters
Vol. 38

Sep-Oct 2001
Reactions of Cyclic Oxalyl Compounds
1059
Table 2
Distances (pm)
I
II
I
II
I
II
N(1)-C(2)
N(1)-N(200)
C(2)-C(3)
C(2)-C(11)
C(3)-C(4)
C(3)-C(8)
C(4)-C(5)
C(5)-C(6)
C(6)-C(7)
C(7)-C(8)
C(8)-C(9)
C(9)-C(10)
C(10)-C(11)
C(11)-C(12)
128.5(5)
145.7(4)
146.7(5)
152.6(5)
140.5(6)
139.1(6)
137.9(7)
137.1(7)
137.0(7)
139.3(6)
150.8(6)
152.0(6)
153.6(5)
151.5(4)
128.4(4)
145.6(4)
147.7(5)
152.1(5)
139.8(5)
139.9(5)
138.4(6)
136.9(6)
137.3(6)
139.4(6)
150.4(6)
151.7(6)
154.2(5)
151.3(5)
C(12)-N(13)
C(12)-C(21)
N(13)-C(14)
C(14)-C(15)
C(14)-C(19)
C(16)-(17)
C(16)-C(17)
C(17)-C(18)
C(18)-C(19)
C(19)-N(20)
N(20)-C(21)
N(20)-H
129.0(4)
147.7(5)
140.0(5)
139.1(5)
139.4(5)
137.7(6)
138.1(6)
136.6(5)
139.4(5)
138.1(4)
135.5(5)
102(3)
129.6(4)
148.4(5)
139.8(5)
140.0(5)
139.1(6)
137.2(6)
137.7(8)
137.6(6)
139.5(5)
138.4(4)
135.6(4)
102(4)
N(200)-C(201)
N(200)-C(207)
C(201)-C(202)
C(201)-C(206)
C(202-C(203))
C(203)-C(204)
C(204)-C(205)
C(205)-C(206)
C(207)-C(208)
C(208)-C(209)
C(209)-C(210)
C(210)-C(211)
C(211)-C(212)
144.9(5)
143.4(5)
137.6(6)
138.0(6)
139.3(6)
137.1(7)
137.5(6)
138.1(6)
137.8(6)
138.7(6)
136.2(7)
136.6(7)
138.7(6)
141.6(4)
145.0(4)
139.1(5)
139.2(5)
139.0(5)
137.7(6)
138.2(6)
139.2(5)
138.0(5)
138.3(6)
136.8(6)
137.6(6)
139.2(6)
C(21)-O(21)
124.4(4)
124.0(4)
Angles (°)
I
II
I
II
I
II
C(2)-N(1)-N(200)
N(1)-C(2)-C(3)
N(1)-C(2)-C(11)
C(3)-C(2)-C(11)
C(2)-C(3)-C(4)
C(2)-C(3)-C(8)
C(4)-C(3)C(8)
C(3)-C(4)-C(5)
C(4)-C(5)-C(6)
C(5)-C(6)-C(7)
C(6)-C(7)-C(8)
C(3)-C(7)-C(7)
C(3)-C(8)-C(9)
C(7)-C(8)-C(9)
C(8)-C(9)-C(10)
C(9)-C(10)-C(11)
C(2)-C(11)-C(10)
C(2)-C(11)-C(12)
113.7(3)
116.1(3)
124.6(3)
119.3(3)
120.3(4)
120.4(3)
119.2(4)
120.1(4)
120.6(4)
119.7(4)
121.4(4)
118.9(4)
119.9(4)
121.2(4)
109.5(3)
110.3(3)
112.4(3)
112.1(2)
113.3(3)
116.8(3)
123.9(3)
119.3(3)
119.6(3)
120.8(3)
119.6(3)
120.1(4)
120.3(4)
120.0(4)
120.0(4)
118.5(4)
119.9(3)
121.6(4)
110.3(3)
111.8(3)
112.1(3)
110.2(3)
110.0(3)
C(11)-C(12)-N(13)
C(11)-C(12)-C(21)
N(13)-C(12)-C(21)
C(12)-N(13)-C(14)
N(13)-C(14)-C(15)
N(13)-C(14)-C(19)
C(15)-C(14)-C(19)
C(14)-C(15)-C(16)
C(15)-C(16)C(17)
C(16)-C(17)-C(18)
C(17)-C(18)-C(19)
C(14)-C(19)-C(18)
C(14)-C(19)-N(20)
C(18)-C(19)-N(20)
C(19)-N(20)-C(21)
C(21)-N(20)-H
120.5(3)
115.4(3)
124.0(3)
118.1(3)
119.5(4)
121.6(3)
118.9(3)
120.4(4)
119.7(4)
121.6(4)
118.8(4)
120.7(3)
118.0(3)
121.3(3)
123.0(3)
119(2)
120.5(3)
N(1)-N(200)-C(201)
N(1)-N(200)-C(207)
C(201)-N(200)C(207)
N(200)-C(201)-C(202)
N(200)-C(201)-C(206)
C(202)-C(201)-C(206)
C(201)-C(202)-C(203)
C(202)-C(203)-C(204)
C(203)-C(204)-C(205)
C(204)-C(205)-C(206)
C(201)-C(206)-C(205)
N(200)-C(207)-C(208)
N(200)-C(207)-C(212)
C(208)-C(207)-C(212)
C(207)-C(208)-C(209)
C(208)-C(209)-C(210)
C(209)-C(210)-C(211)
C(210)-C(211)-C(212)
C(207)-C(212)-C(211)
110.2(3)
112.6(2)
109.3(2)
116.7(3)
118.9(3)
122.1(3)
118.9(3)
119.9(3)
121.3(4)
118.9(3)
120.7(4)
120.3(3)
119.2(3)
120.2(3)
120.2(3)
120.2(3)
120.0(4)
120.2(4)
120.6(4)
118.9(3)
116.1(3)
123.3(3)
118.7(3)
119.1(3)
121.3(3)
119.6(3)
119.3(4)
120.8(4)
121.0(4)
118.4(4)
120.4(3)
118.6(3)
121.0(3)
122.7(3)
116(2)
109.7(3)
116.5(3)
122.5(4)
119.6(3)
120.5(4)
119.0(4)
120.7(4)
119.7(4)
120.3(4)
119.8(4)
123.5(3)
118.7(4)
117.8(4)
120.9(4)
120.7(5)
119.6(4)
120.5(4)
120.5(4)
C(21)-N(20)-H
118(2)
121(2)
C(12)-C(21)-N(20)
C(12)-C(21)-O(21)
N(20)-C(21)-O(21)
114.9(3)
123.2(3)
121.9(4)
115.3(3)
122.5(3)
122.2(3)
C(10)-C(11)-C(12) 110.8(3)
quinoxalinone ring is planar within standard deviations.
From the packing plot of 5b (Figure 2) "stacking" of two
quinoxalinones with one phenyl group of the diphenyl-
hydrazone unit each becomes evident, as well as the
association of two molecules of 5b via hydrogen bridges
N(20) - H(1) .....O(21).
From the ir spectra of 5 lactam carbonyl absorptions are
-1
observed in the 1650-1665 cm region as expected [31],
1
while from the H nmr spectra of 5a,b,f characteristic
signals for the C-H`s are found at δ 4.2, 4.8, and 5.1 ppm,
13
respectively. The C nmr data also agree well with the
established molecular skeleton of 5b. The assignment was
achieved from coupling as well as comparison with
structural analogues, e.g., 3-methylquinoxalin-2-one [34]
and 2-(3-oxo-quinoxalinyl)-acetophenon-N,N-diphenyl-
3
hydrazone [32]. The signals of the C=O at 155.3 (q, J =
3
3
2 Hz), 155.5 (5b, d, J = 2 Hz) and 155.4 (t, J= 3.5 Hz), of

1060
G. Kollenz, R. Theuer, K. Peters and E.-M. Peters
Vol. 38
Table 3
X-Ray Structure Analysis of 5b - Experimental Details
compounds exhibit λ
420 nm (ε = 10770) for 6b, and 352 (ε = 12100), 370 nm
(ε = 10500) for 6f, respectively.
values at 370 (ε = 19100),
max
Yellow crystal
Empirical formula
Crystal size
Crystal system
Space group
Unit cell dimensions
(standard deviations)
C H N O
30 24 4
Thermolysis of Compounds 2, 4 and 6.
0.2 x 0.8 x 0.05
triclinic
Heating of fused pyrrolones 2b,c,e,f in boiling xylene
did not afford the corresponding rearranged diazapro-
pellanes as expected and outlined in the Chart, but instead
the N-unsubstituted pyrrolones 3 were obtained as a result
of loss of diphenylamine or methylphenylamine,
respectively (see Scheme 1). From thermolysis of
thiosemicarbazone derivatives 4 no distinct reaction
product could be isolated out of the complex reaction
mixture. Finally, pyrrolo[2,3-b]quinoxaline 6b, when
refluxed in xylene for 4 hours, again gave the deaminated
derivative 7 as the only isolable reaction product, similarly
to the formation of compounds 3 starting with 2. In
addition, the pyrrolo-quinoxaline 8, related to 6b and
obtained according to a known procedure [32], revealed a
quite similar behaviour during thermolysis leading to
compound 9.
-
Pi (2)
a = 1526.7(6) pm α = 91.71 (4)°
b = 1548.2(6) pm ß = 100.70 (4)°
c = 1027.7(4) pm γ = 87.36 (4)°
4
Z
-3
d
[g.cm ]
1.272
calc
Syntex-P3 four circle diffractometer
Measurement of intensities
ω -scan, MoKα - radiation
scan width 1°, 2θ
3146
= 55°
max
Reflections collected
Reflections observed
(F>3σ)
3111
2
Refinement method
Full-matrix least-squares on F
0.034
R
aniso
the C=N at 161.8 (m) and 166.8 (5b, m) as well as of the
C-3 of the quinoxalinone moiety at 159.7 (q, J = 7.5 Hz),
158.8 (5b, m) and 161.8 (m) correspond well among each
other.
The molecular scaffold of the pyrrolo[2,3-b]quin-
oxaline derivatives 6b,f was characterized by their
molecular formula deduced from the results of
elemental anlysis, as well as the lack of any carbonyl
and NH absorption bands in the IR-spectrum. The uv
spectra of the yellow coloured and fluorescent
2
EXPERIMENTAL
Melting points were acquired on a Tottoli Apparatus and are
uncorrected. Ir-spectra (potassium bromide pellets) were
1
13
recorded on a Perkin Elmer Model 298. The H and C nmr
spectra were obtained with a Varian XL 200 operating at
200 MHz and 50 MHz respectively, a Bruker AMX 360
operating at 360 MHz and 90 MHz, respectively, a Bruker DMX
Avance operating at 500 and 125 MHz, respectively, and TMS as
internal standard. The ms measurements were performed on a
Varian MAT 111 spectrometer and elemental analyses were
obtained using a Carlo Erba Elemental Analyzer 1106.
Synthesis of 3-Diphenylmethylene-pyrrol-2-ones 2.
General Procedure.
The respective pyrrol-2-one derivative 1 (1 mmole) [7] as a
solid was mixed with an slight excess (1.5 mmoles) of
diphenylketene [11] and heated to 60 °C (1a-c) or 110 °C (1d-f)
under dry nitrogen until the evolution of carbon dioxide ceased.
Cooling to room termperature and triturating of the crude
residue with dry ether afforded the compounds 2 as red/orange
products which were recrystallized from ethanol (2a-c) or
n-butanol (2d-f).
1-Diphenylamino-3-diphenylmethylene-3,4-dihydro-indeno-
[1,2-b]pyrrol-2(1H)-one 2a.
This compound was obtained by the general procedure as red
crystals, mp 167 °C, yield 88%; ir (potassium bromide): 1710
-1
1
(C=O), 1585 cm (C=C); H nmr (CDCl ): δ 3.06 (s, 2H),
3
13
7.16-7.47 (m, 24H) ppm; C nmr (CDCl ): δ 169.2 (C=O), 149.5,
3
148.5, 145.8, 145.2, 141.7, 138.8, 133.5, 118.5 (quarternary
carbons), 131.0-119.2 (aromatic carbons), 34.5 (CH ) ppm.
2
Anal. Calcd. for C
H N O: C, 86.02; H, 5.22; N, 5.58.
36 26 2
Found: C, 86.05; H, 5.35; N, 5.57.
Figure 2

Sep-Oct 2001
Reactions of Cyclic Oxalyl Compounds
1061
1-Diphenylamino-3-diphenylmethylene-3H-4,5-dihydrobenz-
[g]indol-2(1H)-one (2b).
3-Diphenylmethylene-3H-4,5-dihydrobenz[g]indole-2(1H)-one
(3a).
a) Diphenylketene 0.5 ml (2.85 mmoles) and 0.75 g
(2 mmoles) of 1b were heated to 115 °C under dry nitrogen until
the evolution of carbon dioxide is over. After cooling to room
temperature and treating with dry ether, the crude product was
recrystallized from n-butanol affording orange crystals (0.42 g,
60%), mp 287-290 °C.
This compound was obtained by the general procedure as red
crystals, mp 163 °C, yield 90%; ir (potassium bromide): 1715
-1
1
(C=O), 1585 cm (C=C); H nmr (CDCl ): δ 1.85 (t, J = 7.5 Hz,
3
13
2H), 2.70 (t, J = 7.5 Hz, 2H), 7.01-7.4 (m, 24 H) ppm; C nmr
(CDCl ): δ 168.0 (C=O), 151.9, 145.2, 141.9, 139.6, 137.5,
3
129.9, 126.3, 113.2 (quarternary carbons), 131.6-119.5 (aromatic
b) Dry xylene (10 ml) and 0.3 g (0.58 mmole) of 2b were
heated at 140 °C for 1 hour. Then the solvent was evaporated and
the crude residue recrystallized from n-butanol to give 0.1 g
(46%) of 3a.
carbons), 29.9 (t, J = 142.5 Hz, CH ), 21.85 (t, J = 142.5 Hz,
2
+
+
CH ) ppm; ms: m/z 516 (M ), 347 (M - (Ph) N), 270, 215.
2
2
Anal. Calcd for C
H N O: C, 86.01; H, 5.46; N, 5.42.
37 28 2
Found: C, 86.08; H, 5.44; N, 5.37.
c) During reflux of 0.3 g (0.66 mmole) of 2e in dry xylene
(10 ml) for 20 min the orange coloured product started to
precipitate. After removing most of the solvent and cooling to
room temperature, 3a (0.13 g, 56%) was obtained, mp 291°C; ir
1-Diphenylamino-3-diphenylmethylene-3,4-dihydro-1-benzo-
thiopyrano[4,3-b]pyrrol-2(1H)-one (2c).
This compound was obtained by the general procedure as red
crystals, mp 150 °C, yield 76%; ir (potassium bromide): 1715
-1
1
(potassium bromide) : 1685 (C=O), 1610 cm (C=C); H nmr
(d -DMSO): δ 1.66 (t, J = 7.9 Hz, 2H), 2.63 (t, J = 7.9 Hz, 2H),
-1
1
6
(C=O), 1585 cm (C=C); H nmr (CDCl ): δ 2.89 (s, 2H),
3
13
7.11- 7.52 (m, 14H), 10.33 (s, 1H) ppm; C nmr (d -DMSO): δ
6
6.15-7.6 (m, 24H) ppm.
169.3 (C=O), 148.4, 142.0, 141.0, 139.0, 137.0, 133.8, 111.0
Anal. Calcd for C
H N OS: C, 80.87; H, 4.91; N, 5.24; S,
36 26 2
(quarternary carbons), 28.7 (CH2), 21.6 (CH ) ppm; ms (70 eV):
2
6.00. Found: C, 80.75; H, 5.02; N, 5.14; S, 6.04.
+
+
m/z 349 (M ), 180 (M - (Ph) C).
2
3-Diphenylmethylene-1-(N-methyl-N-phenylamino)-3,4-dihydro-
indeno[1,2-b]pyrrol-2(1H)-one (2d).
Anal. Calcd for C
C, 85.72; H, 5.39; N, 3.93.
H NO: C, 85.92; H, 5.49; N, 4.01. Found:
25 19
This compound was obtained by the general procedure as
orange crystals, mp 110 °C, yield 60%; ir (potassium bromide):
3-Diphenylmethylene-3,4-dihydro-1-benzothiopyrano[4,3-b]-
pyrrole-2(1H)-one (3b).
-1
1
1715 (C=O), 1595 cm (C=C); H nmr (CDCl ): δ 3.06, 3.08
3
a) A mixture of 0.4 g (1.5 mmoles) of 1c and 0.4 ml
(2.3 mmoles) of diphenylketene was heated to 115 °C until the
evolution of carbon dioxide ceased. Dark red crystals of 3b
(0.1 g, 26%) were obtained after cooling the reaction mixture to
room temperature, triturating with ether and recrystallization
from n-butanol; mp 220 °C.
b) A suspension of 0.2 g (0.37 mmole) of 2c in dry xylene
(10 ml) was refluxed for 1 hour. Then the solvent was removed in
vacuo and the crude residue treated with ether and recrystallized
from n-butanol to afford 0.025 g (18%) of dark red 3b.
(AB-system, J = 14.2 Hz, 2H), 3.45 (s, 3H), 6.88-7.48 (m, 19H)
13
ppm; C nmr (CDCl ): δ 168.5 (C=O) 149.1, 148.0, 141.5,
3
138.0, 133.2, 117.8 (quarternary carbons), 132-119.0 (aromat),
39.1 (CH ), 34.0 (CH ) ppm.
3
2
Anal. Calcd for C
H N O: C, 84.51; H, 5.49; N, 6.36.
31 24 2
Found: C, 84.66; H, 5.69; N, 6.18.
3-Diphenylmethylene-1-(N-methyl-N-phenylamino)-3H-4,5-
dihydrobenz[g]indol-2(1H)-one (2e).
This compound was obtained by the general procedure as
orange crystals, mp 162 °C, yield 54%; ir (potassium bromide):
c) Compound 2f 0.3 g (0.64 mmole) were treated under
identical reaction conditions and work-up as described with b) to
give 0.05 g (22%) of 3b mp. 221 °C; ir (potassium bromide):
-1
1
1705 (C=O), 1595 cm (C=C); H nmr (CDCl ): δ 1.80 (m, 1H),
3
1.91 (m, 1H), 2.74 (t, J = 7.2 Hz, 2H), 3.37 (s, 3H), 6.85-7.64
-1
1
1685 (C=O), 1610 cm (C=C); H nmr (CDCl ): δ 2.97 (s, 2H),
3
13
(m, 19H) ppm; C nmr (CDCl ): δ 167.9 (C=O), 151.5, 149.2,
3
7.07-7.48 (m, 14H), 8.5 (br s, 1H).
141.8, 139.8, 138.2, 137.5, 127.0, 126.6, 112.4 (quarternary
Anal. Calcd for C
H NOS: C, 78.44; H, 4.67; N, 3.81; S,
24 17
carbons), 131.4-112.7 (aromatic carbons), 38.9 (CH ), 29.8
8.72. Found: C, 78.32; H, 4.84; N, 3.64; S, 8.61.
Synthesis of Pyrrole-2,3-dione-3-thiosemicarbazones 4.
General Procedure.
3
(CH ), 21.9 (CH ) ppm.
2
2
Anal. Calcd for C
H N O: C, 84.54; H, 5.77; N, 6.16.
32 26 2
Found: C, 84.67; H, 5.83; N, 5.98.
3-Diphenylmethylene-1-(N-methyl-N-phenylamino)-3,4-dihydro-
1-benzothiopyrano[4,3-b]pyrrole-2(1H)-one (2f).
The pyrrole-2,3-dione derivatives 1a,b,f,g, together with a
slight excess of thiosemicarbazide and catalytic amounts of
etheral hydrogen chloride, were refluxed in ethanol for 1 hour.
During cooling to room temperature an orange product
precipitated which could be recrystallized from ethyl acetate.
This compound was obtained by the general procedure as
orange crystals, mp 165 °C, yield 67%; ir (potassium bromide):
-1
1
1705 (C=O), 1590 cm (C=C); H nmr (CDCl ): δ 2.73, 3.145
3
1-Diphenylamino-3-thiosemicarbazono-3,4,-dihydro-
indeno[1,2-b]pyrrol-2-one (4a).
(AB-system, J = 15.1 Hz, 2H), 3.29 (s, 3H), 6.84-7.43 (m, 19H)
13
ppm; C nmr (CDCl ): δ 166.85 (C=O), 152.9, 148.9, 141.7,
3
139.3, 138.7, 133.9, 126.1, 108.6 (quarternary carbons), 38.9
(CH ), 24.1(CH ) ppm.
This compound was obtained by the general procedure as
orange crystals, mp 190 °C, yield 66%; ir (potassium bromide):
3
2
-1
1
Anal. Calcd for C
H N OS: C, 78.78; H, 5.13; N, 5.93; S,
3400, 3200, 3120 (NH, NH ), 1715 (C=O), 1590 cm (C=C); H
31 24 2
2
6.78. Found: C, 78.93; H, 5.15; N, 5.61; S, 6.90.
nmr (d -DMSO): δ 3.74 (s, 2H), 7.07-7.63 (m, 14H), 8.57
6

1062
G. Kollenz, R. Theuer, K. Peters and E.-M. Peters
Vol. 38
13
3-(1-Diphenylhydrazono-1,2,3,4-tetrahydronaphthalin-2-yl)-
(s, 1H), 9.03 (s, 1H), 12.15 (s, 1H) ppm; C nmr (d -DMSO): δ
6
quinoxalin-2(1H)-one (5b).
178.6 (C=S), 163.3 (C=O), 152.5, 146.9, 144.0, 132.8, 130.7,
115.3 (quarternary carbons), 31.5 (CH ) ppm.
2
In slightly changing the general procedure, this reaction was
performed in ethanol adding catalytic amounts of p-toluene
sulfonic acid and stirring for 120 hours at room temperature. The
product was obtained as yellow crystals, mp 194 °C, yield 48%
Anal. Calcd for C
H N OS: C, 67.74; H, 4.51; N, 16.47; S,
24 19 5
7.53. Found: C, 67.94; H, 4.62; N, 16.42; S, 7.25.
1-Diphenylamino-3-thiosemicarbazono-3,4-dihydrobenz-
[g]indol-2-one (4b).
(from ethanol); ir (potassium bromide): 3450 (b, NH), 1665
-1
(C=O), 1590, 1490 cm ; UV-VIS (methanol): λ
345 nm
max
This compound was obtained by the general procedure as
orange crystals, mp 167 °C, yield 86%; ir (potassium bromide):
1
(ε 10380); H nmr (CDCl ): δ 2.2 (b, CH ), 2.7 (b, CH ), 4.8
(s, CH), 6.6-8.7 (m, aromat), 12.2 (s, NH) ppm; C nmr
(CDCl ): δ 166.8 (m, C=N-N), 158.8 (m, C=N), 155.5 (d, J =
2Hz, C=O), 148.0 (t, J = 8.5Hz, N-C(phenyl)), 140.2, 133.5,
130.8, 129.9 (quarternary aryl-C), 41.7 (d, J = 140 Hz, CH),
3
2
2
13
1
3480, 3360, 3215 (NH, NH ), 1695 (C=O), 1575 (C=C); H nmr
3
2
3
(CDCl ): δ 2.66 (t, J = 8.2 Hz, 2H), 3.01 (t, J = 8.2 Hz, 2H), 6.48
3
3
13
(s, 1H), 7.44 (s, 1H), 7.1-7.77 (m, 14H), 12.5 (s, 1H) ppm; C nmr
CH
(CDCl ): δ 179.7 (C=S), 162.0 (C=O), 144.7, 142.9, 138.3, 132.4,
3
27.1, 26.7 (t, J = 130 Hz, 2 CH ) ppm.
CH
2
125.5, 109.8 (quarternary carbons), 28.6 (CH ), 17.6 (CH ) ppm.
Anal. Calcd for C
H
N O: C, 78.91; H, 5.31; N, 12.27.
2
2
30 24
4
Anal. Calcd for C
H N OS: C, 68.31; H, 4.83; N, 15.94,
Found: C, 79.15; H, 5.30; N, 12.22.
25 21 5
S, 7.29. Found: C, 68.34; H, 4.78; N, 15.95; S, 7.11.
3-(1-Diphenylhydrazonothiochroman-2-yl)-quinoxalin-2(1H)-
one (5c).
1-(N-Methyl-N-phenylamino)-3-thiosemicarbazono-4H-1-benzo-
thiopyrano[4,3-b]pyrrol-2-one (4f).
This compound was obtained by the general procedure as pale
yellow solid, mp 260 °C, yield 30% (from n-butanol); ir (potas-
sium bromide): 3400-3100 (b, NH), 1655 (C=O), 1595, 1480
This compound was obtained by the general procedure as
orange crystals, mp 196 °C, yield 52%; ir (potassium bromide):
-1
1
-1
1
3400, 3230, 3140 (NH, NH ), 1705 (C=O), 1600 cm (C=C); H
cm ; UV-VIS (methanol): λ
340 nm (ε 10260). H nmr
2
max
nmr (CDCl ): δ 3.32 (s, 3H), 3.735, 3.855 (AB-system, J = 14.5
(d -DMSO): δ 3.42 (m, CH ), 5.1 (m, CH), 6.3-8.7 (m, aromat),
3
6
2
Hz, 2H), 6.43 (s, 1H), 7.38 (s, 1H), 6.84-7.73 (m, 9H), 12.49
(s, 1H) ppm.
12.20 (br s, NH) ppm.
Anal. Calcd for C
H N OS: C, 73.39; H, 4.68; N, 11.81; S,
29 22 4
Anal. Calcd for C
H N OS : C, 57.69; H, 4.34; N, 17.71; S,
6.76. Found: C, 73.57; H, 4.40; N, 11.70; S, 6.74.
19 17 5 2
16.21. Found: C, 57.85; H, 4.20; N, 17.51; S, 15.78.
3-(1-N-Methyl-N-phenylhydrazonothiochroman-2-yl)quinox-
alin-2(1H)-one (5f).
1-(N-Methyl-N-phenylamino)-3-thiosemicarbazono-3,4,5,6-
tetrahydrobenzo[6,7]cyclohepta[1,2-b]pyrrol-2-one (4g).
This compound was obtained by the general procedure as yellow
solid, mp 195 °C, yield 78% (from ethanol); ir (potassium bromide):
This compound was obtained by the general procedure as
orange crystals, mp 183 °C, yield 81%; ir (potassium bromide):
-1
3400-3000 (b, NH), 1660 (C=O), 1595, 1480 cm ; UV-VIS
1
-1
1
(methanol): λ
350 nm (ε 12010); H nmr (d -DMSO): δ 2.84 (s,
3400, 3230, 3140 (NH, NH ), 1700 (C=O), 1595 cm (C=C); H
max
6
2
CH ), 3.38, 3.45 (m, CH ), 5.1 (m, CH), 6.5-8.5 (m, aromat), 12.17
nmr (CDCl ): δ 2.17 (m, 1H ), 2.255 (m, 1H ), 2.41 (m, 1H ),
3
2
3
ax
eq
ax
13
(br s, NH); C nmr (d -DMSO): δ 167.3 (C=O), 158.4, 153.8,
2.55 (m, 1H ), 2.80 (m, 2H), 3.22 (s, 3H), 6.48 (s, 1H), 7.45
6
eq
149.7, 136.7, 131.7, 131.4, 129.4 (quarternary carbons), 42.2 (d,
(s, 1H), 6.79-7.32 (m, 9H) ppm.
J
= 139 Hz, CH) 29.7 (t, J = 131 Hz, CH ) ppm.
Anal. Calcd for C
H N OS: C, 64.45; H, 5.37; N, 17.90.
CH
CH 2
21 21 5
Anal. Calcd for C
H N OS: C, 69.87; H, 4.90; N, 13.58; S,
24 20 4
Found: C, 64.12; H, 5.36; N, 17.51.
Synthesis of the Quinoxaline-2-ones 5.
General Procedure.
7.76. Found: C, 70.11; H, 5.01; N, 13.56; S, 7.90.
3-[1-(N,N-Diphenylhydrazino)-3,4-dihydro-2-naphthyl]-quinox-
aline-2(1H)-one (5I).
The fused pyrrolediones 1a,b,c,e,f,g and 1,2-diamino-
benzene (molar ratio 1:2) were dissolved in dichloromethane
and catalytic amounts of etheral HCl were added. Then the
solution was stirred for 48 hours at room temperature and the
corresponding reaction products 5 either precipitated or were
obtained after evaporation of the solvent and triturating with
ether and recrystallized from the proper solvent (ethanol,
n-butanol or toluene).
Compound 5b (0.25 g) were reacted with 5 ml of oxalic acid
dichloride at 25 °C for 3 hours. The reaction mixture is diluted by
adding 5 ml of anhydrous ether. After suction filtration the crude
product is carefully washed with anhydrous ether and dried to
afford 0.2 g (80%) of colourless 5I, mp 180 °C; ir (potassium
-1
bromide): 3450-3300 (b, NH), 1640 (w,C=O), 1590, 1490 cm .
Anal. Calcd for C
H N O: C, 78.91; H, 5.31; N, 12.27.
30 24 4
Found: 78.71; H, 4.97; N, 12.06.
3-(1-Diphenylhydrazonoindan-2-yl)-quinoxalin-2(1H)-one (5a).
13-Diphenylamino-5,6-dihydronaphtho[2,1:4,5]pyrrolo[2,3-b]-
quinoxaline (6b).
This compound was obtained by the general procedure as
orange-yellow solid, mp 175-177 °C, yield 53% (from toluene);
ir (potassium bromide): 3450 (b, NH), 1665 (C=O), 1595, 1490
a) Compound 5I 0.2 g (0.44 mmoles) were heated under reflux
in 20 ml of aequous ethanol (80%) for 30 minutes to afford bright
yellow fluorescent needles, mp 178 °C (from n-butanol), yield
0.1 g (52%).
-1
1
cm ; UV-VIS (methanol): λ
467 nm (ε 7984); H nmr
max
(d -DMSO): δ 2.35 (s, CH ), 4.2 (s, CH), 6.7-8.2 (aromat), 12.3
6
2
b) Compound 1b 0.35 g (0.96 mmole), 0.2 g (1.85 mmoles) of
1,2-diaminobenzene and 0.01 ml of concentrated hydrochloric
acid were refluxed in 20 ml of ethanol for 48 hours. Evaporation
(NH) ppm.
Anal. Calcd for C
Found: C, 78.53; H, 4.97; N, 12.86.
H N O: C, 78.70; H, 5.02; N, 12.66.
29 22 4

Sep-Oct 2001
Reactions of Cyclic Oxalyl Compounds
1063
of the solvent and triturating with ether afforded yellow
3-Benzyl-2-phenylpyrrolo[2,3-b]quinoxaline (9).
fluorescent crystals, mp 177 °C (from n-butanol), yield 0.25 g
(60%); ir (potassium chloride): 1590, 1490 cm , no carbonyl
Compound 8 0.15 g (0.30 mmoles) [32] was suspended in 10 ml
of dry xylene and refluxed for 4 hours. The solvent was evaporated
and the oily residue crystallized upon triturating with ether (10 ml)
to afford 0.055 g (55%) of yellow needles, mp 210 °C; ir
-1
absorption; uv-vis (methanol): λ
370 (ε 19100), 420 nm
max
(ε 10770); fluorescence spectrum (methanol): λ
420 nm, λ
excit
1
518 nm; H nmr (CDCl ): δ 3.16, 3.27 (A B -system, J ≈ 8
emiss
3
2 2
-1
(potassium bromide): 3200-3000 (b, NH), 1460(w), 1410(w) cm ;
13
Hz, 4H), 7.01-8.17 (m, 18H) ppm; C nmr (CDCl ): δ 145.3,
3
uv-vis (methanol): λ
352 nm (ε 9200); fluorescence spectrum
max
143.9, 143.4, 141.6, 139.8, 139.2, 126.8, 110.5 (quarternary- C),
129.5, 129.3, 129.02, 128.8, 127.5, 127.1, 124.3, 123.5, 119.77
1
(methanol): λ
352 nm, λ
505 nm; H nmr (CDCl ): δ 4.47
excit
emiss
3
(s, 2H), 7.17-8.24 (m, 14H), 10.48 (s, 1H) ppm.
Anal. Calcd for C N : C, 82.35; H, 5.12; N, 12.53. Found:
(aryl-CH), 29.6, 18.4 (CH ) ppm.
2
H
23 17
3
Anal. Calcd for C
H N : C, 82.15; H, 5.07; N, 12.78. Found:
30 22 4
C, 82.16; H, 5.11; N, 12.34.
C, 82.31; H, 5.00; N, 12.54.
13-N-Methyl-N-phenylamino-6H-thiochromeno[3,4:4,5]pyrrolo-
[2,3-b]quinoxaline (6f).
REFERENCES AND NOTES
a) Compound 1f 0.25 g (0.78 mmoles), 0.27 g (2.5 mmoles) of
1,2-diaminobenzene together with 0.1 ml of concentrated
hydrochloric acid were dissolved in 20 ml of ethanol and refluxed
for 72 hours. After cooling and evaporation of the solvent an oily
residue by triturating with ether afforded yellow fluorescent
crystals, mp 175 °C (from n-butanol), yield 0.05 g (16%).
[1] Part 42: A. Stadler, K. Zangger, F. Belaj and G. Kollenz,
Tetrahedron, 57, 6757 (2001).
[2] G. Kollenz, E. Ziegler, M. Eder and E. Prewedourakis,
Monatsh. Chem., 101, 1597 (1970).
[3] G. Kollenz, Monatsh. Chem., 102, 108 (1971).
[4] G. Kollenz, Monatsh. Chem., 103, 947 (1972).
[5] G. Kollenz and Ch. Labes, Liebigs Ann. Chem., 1979 (1975).
[6] G. Kollenz, Monatsh. Chem., 109, 249 (1978).
[7] G. Kollenz, R. Theuer, W. Ott, K. Peters, E. M.Peters and H.
G. von Schnering, Heterocycles, 27, 479 (1988).
[8] G. Kollenz and Ch. Labes, Liebigs Ann. Chem., 174 (1976).
[9] Preliminary Communication: G. Hutter, H. J. Shine,
G. Kollenz and W. Subotkowski, Synthesis and Applications of
Isotopically Labelled Compounds 1991, E. Buncel and G. W. Kabalka,
eds, Elsevier Science Publishers, Amsterdam 1991, p. 652.
[10] H. Staudinger, Liebigs Ann. Chem., 356, 51 (1907).
[11] L. I. Smith and H. H. Hoehn, Org. Synth. Coll. Vol. III, 356
(1955).
[12] S. Scheibye, R. Shabana, S. O. Lawesson and C. Romming,
Tetrahedron, 38, 993 (1982).
[13] G. Kollenz, G. Penn, R. Theuer, W. M. F. Fabian, H. A.
Abd-ElNabi, Xiong Zhang, K. Peters, E. M. Peters and H. G. von
Schnering, Tetrahedron, 52, 5427 (1996).
[14] T. T. Tidwell, Ketenes, J.Wiley & Sons, New York, 1995, p.
564 ff.
[15] L. A. Singer, G. A. Davis and R. L. Knudsen, J. Am. Chem.
Soc., 94, 1188 (1972).
b) Oxalic acid dichloride (5 ml) were added to 0.5 g
(1.05 mmoles) of 5f at room temperature thus forming a pulp.
After 30 minutes 5 ml of anhydrous ether were added and the
solid residue was refluxed in aequous ethanol (80%) for
additional 30 minutes. After cooling to room temperature 0.09 g
(21%) of yellow fluorescent crystals separated, mp. 177 °C; ir
-1
(potassium bromide): 1590, 1490, 1440 cm , no carbonyl
absorption; uv-vis (methanol): λ
352 (ε 12100), 370 nm
max
(ε 10500); fluorescence spectrum (methanol): λ
430 nm, λ
excit
1
535 nm; H nmr (CDCl ): complete assignment by
emiss
3
HMBC/HMQC: δ 3.579 (s, 3H), 4.420 (s, 2H), 6.738 (d, J = 8
Hz, 2H), 6.911 (t, J = 4.5 Hz, 1H), 7.142 (t, J = 4.5 Hz, H-2),
7.249 (t, J = 4.5 Hz, H-3), 7.263 (t, J = 4.5 Hz, 2H), 7.493 (d, J =
7.5 Hz, H-4), 7.630 (t, J = 6.5 Hz, H-9), 7.645 (t, J = 6.5 Hz,
H-10), 7.953 (d, J = 8 Hz, H-1), 7.990 (d, J = 7.5 Hz, H-8), 8.171
13
(d, J = 8 Hz, H-11); C nmr (CDCl ): δ 148.9 (N-Ph), 143.2
3
(C-4a), 139.6 (C-7a, C-11a), 137.6 (C-6b), 136.0 (C-13a), 129.4
(C-3), 129.3 (N-Ph,m), 128.8 (C-8), 128.5 (C-11), 128.1 (C-4),
127.8 (C-9), 127.3 (C-10), 126.5 (C-2), 125.8 (C-1), 125.4
(C-13b), 119.9 (N-Ph,p), 112.6 (N-Ph,o), 105.1 (C-6a), 40.1
(CH ), 21.3 (CH ) ppm.
3
2
[16] R. G. Visser, J. B. P. Baaij, A. C. Bower and H. J. T. Bos,
Tetrahedron Lett., 4343 (1977).
Anal. Calcd for C
H N S: C, 73.06; H, 4.61; N, 14.21.
24 18 4
Found: C, 73.15; H, 4.75; N, 13.99.
[17] D. Borrmann and R. Wegler, Chem. Ber., 102, 64 (1969).
[18] E. Terpetschnig, G. Penn, G. Kollenz, K. Peters, E. M. Peters
and H. G. von Schnering, Tetrahedron, 47, 3045 (1991).
[19] Ch. Belaud, R. Roussakis, Y. Letourneux, N. ElAlami and
J. Villieras, Synth. Commun., 15, 1233 (1985).
[20] H. Ikuta, H. Shirota, S. Kobayashi, Y. Yamagishi, K. Yamada,
I. Yamatsu and K. Katayama, J. Med. Chem., 30, 1995 (1987).
[21] M. J. Kornet, J.Pharm.Sci., 350 (1979).
[22] F. Lovren, I. D. Gaon and B. Bobarevic, Pharmazie, 47, 773
(1992).
[23] F. Lovren, I. D. Gaon and B. Bobarevic, Arch. Pharm., 323,
901 (1990).
5,6-Dihydronaphtho[2,1:4,5]pyrrolo[2,3-b]quinoxaline (7).
Compound 6b 0.3 g (0.68 mmoles) were heated in 10 ml of dry
xylene under reflux for 2 hours. After cooling to room
temperature fine yellow needles precipitate, mp 350 °C <, yield
0.12 g (55%); ir (potassium bromide): 3250-3050 (b, NH),
-1
1625(w), 1590(w), 1490 cm ; uv-vis (methanol): λ
368
423
max
(ε 67250), 418 nm (ε 9770); fluorescence spectrum: λ
513 nm; H nmr (d -DMSO): δ 3.08, 3.11 (A B -
system, J ≈ 6 Hz, 4H), 7.38-8.69 (m, 8H), 13.03 (s, 1H); C nmr
excit
1
nm, λ
emiss
6
2 2
13
(d -DMSO): δ 145.7 (C-12a), 142.35 (C-6b), 140.10 (C-7a),
6
139.89 (C-13a), 139.58 (C-11a), 134.9 (C-4a), 129.95 (C-13b),
129.41, 128.95, 128.66, 127.67, 126.24, 123.82, 120.96, 118.84
(aryl-CH), 114.01 (C-6a), 28.50 (CH ), 18.54 (CH ) ppm.
[24] D. J. Bauer and P. W. Sadler, Brit. J. Pharmacolog.
Chemotherapy, 15, 101 (1960).
[25] D. J. Bauer and P. W. Sadler, Nature, 190, 1167 (1961).
[26] G. D. Pearson and E. F. Zimmermann, Virology, 38, 641
(1969).
2
2
Anal. Calcd for C
H N : C, 79.67; H, 4.83; N, 15.49. Found:
18 13 3
C, 79.43; H, 4.65; N, 15.31.

1064
G. Kollenz, R. Theuer, K. Peters and E.-M. Peters
Vol. 38
[27] L. Heinisch and K. Kramarczyk, J. Prakt. Chem., 314, 682
(1972).
[28] P. W. Sadler, J. Chem. Soc. [London], 957 (1961).
[31] J. L. Bernier and J. P. Henichart, J. Heterocyclic Chem., 16,
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