Uncommon reaction of pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-trione with α-enaminoester

Full text of DOI:10.1134/S1070428008070282

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2008, Vol. 44, No. 7, pp. 1094−1095. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © N.L. Racheva, Z.G. Aliev, A.N. Maslivets, 2008, published in Zhurnal Organicheskoi Khimii, 2008, Vol. 44, No. 7, pp. 1103−
1104.
SHORT
COMMUNICATIONS
Uncommon Reaction of Pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-trione
with α-Enaminoester
N. L. Rachevaa, Z. G. Alievb, and A. N. Maslivetsa
aPerm State University, Perm, 614990 Russia
e-mail: koh2@psu.ru
bInstitute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Russia
Received March 12, 2007
DOI: 10.1134/S1070428008070282
2,9-diazatricyclo[6.2.1.01,5]undec-5-ene-8-carboxylate
(IV) whose structure was proved by XRD analysis.
Reactions with α-enaminoesters of 1H-pyrrole-2,3-
diones, in particular, those fused with azaheterocycles
by the [a] side, were not formerly described.
Evidently in the first stage of the reaction the activated
β-CH group of the enamino fragment of α-enaminoester
II added to the carbon atom in the position 3a of pyrrolo-
benzoxazinetrione I followed by (Z)Q(E) isomerization
and a closure of a pyrrole ring through an intramolecular
attack of the free amino group of the side chain of α-en-
aminoester II on the lactone carbonyl of the benzoxazine
ring of compound I with its opening of C4–O5 bond and
the formation of intermediate substituted pyrrole-2-spiro-
3'-pyrrole III. Formed spiro compound III at attempted
recrystallization suffered an intramolecular cyclization
by addition of an enol OH group of the tautomer
In reaction of 3-benzoyl-1H-pyrrolo[2,1-c][1,4]benz-
oxazine-1,2,4-trione (I) with a potential 1,3-CH,NH-
binucleophile, α-enaminoester methyl (2Ε)-2-anilino-4-
oxo-4-phenyl-2-butenoate (II), at boiling in 1:1 ratio in
anhydrous benzene we obtained in 20–25 min (till
decoloration) in a virtually quantitative yield methyl 4,9-
dibenzoyl-3-hydroxy-1-(2-hydroxyphenyl)-2,6-dioxo-7-
phenyl-1,7-diazaspiro[4.4]nona-3,8-diene-8-carboxylate
(III). Compound III during recrystallization from ethyl
acetate underwent cyclization into methyl 11-benzoyl-
2-(2-hydroxyphenyl)-3,4,10-trioxo-6,9-diphenyl-7-oxa-
O
N
O
COPh
O
N
O
C
COPh
+
Ph CH
O.
COOMe
Ph
NHPh
C
COOMe
N
.
COPh
.
H
O
O
II
I
O
OH
Ph
N
O
Ph
N
Ph
N
OH
OH
OH
O
Heating
[1.5]H
,
COOMe
H
O
COOMe
O
COOMe
COPh
Heating
N
N
N
COPh
COPh
COPh
OH
O
O
O
Ph
O
IV
OH
III
O
Ph
V
1094

UNCOMMON REACTION OF PYRROLO[2,1-c][1,4]BENZOXAZINE-1,2,4-TRIONE
1095
Methyl 11-benzoyl-2-(2-hydroxyphenyl)-3,4,10-
trioxo-6,9-diphenyl-7-oxa-2,9-diazatricyclo-
[6.2.1.01,5]undec-5-ene-8-carboxylate (IV). A solution
of 0.5 mmol of compound III was recrystallized from
10 ml of ethyl acetate, cooled, the separated precipitate
was filtered off. Yield 92%, mp 201–203°C (from ethyl
acetate). IR spectrum, ν, cm–1: 3227 br (OHphenol), 1776
(COOMe), 1751 (C2=O), 1721 (C5=O), 1707 (COPh).
1H NMR spectrum, δ, ppm: 3.22 s (3H, OMe), 5.29 s (1H,
C11H), 6.94–7.98 group of signals (19H, 3Ph + C6H4),
10.01 s (1H, OHphenol). Found, %: C 69.89; H 4.07; N 4.70.
C35H24N2O8. Calculated, %: C 70.00; H 4.03; N 4.66.
hydroxymethylene form V to the carbon atom in the
position 5' in the neighbor pyrrole ring resulting in a com-
pound with a bridging bond IV.
This reaction is the first example of an intramolecular
cyclization of pyrrole-2-spiro-3'-pyrroles with a regio-
selective building of difficultly available functionalized
heterocyclic system of 7-oxa-2,9-diaza-tricyclo-
[6.2.1.01,5]undecane.
Methyl 4,9-dibenzoyl-3-hydroxy-1-(2-hydroxy-
phenyl)2,6-dioxo-7-phenyl-1,7-diazaspiro[4.4]-nona-
3,8-diene-8-carboxylate (III). A solution of 1 mmol of
compound I and 1 mmol of compound II in 10 ml of
anhydrous benzene was boiled for 25 min (till decolora-
tion), the reaction mixture was cooled, the separated
precipitate was filtered off. Yield 87%, mp 200–202°C.
IR spectrum, ν, cm–1: 3152 br (OH), 1770 (COOMe),
1737 (C2'=O), 1724 (C5=O), 1672, 1620 (C3–C=O, C4'–
C=O). 1H NMR spectrum, δ, ppm: 3.20 s (3H, OMe), 7.10–
7.98 group of signals (19H, C6H4 +3Ph), 9.80 s (1H,
OHphenol), 12.60 br.s (1H, OHenol). Found, %: C 70.10; H
4.00; N 4.55. C35H24N2O8. Calculated, %: C 70.00; H 4.03;
N 4.66.
IR spectra of compounds obtained were recorded on
a spectrophotometer FMS-1201 from mulls in mineral
oil. 1H NMR spectra were registered on a spectrometer
Bruker WP-400 from solutions in DMSO-d6, internal
reference TMS. The homogeneity of compounds
synthesized was confirmed by TLC on Silufol plates,
eluent ethyl acetate, development in iodine vapor.
The study was carried out under a financial support
of the Russian Foundation for Basic Research (grant no.
07-03-96036).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 44 No. 5 2008