Decyclization of 5-aryl-4-methyl-2,3-dihydrofuran-2,3-diones by the action of nucleophiles

Article abstract of DOI:10.1023/A:1022508622558

Ring cleavage in 4-methyl-5-phenyl-2,3-dihydrofuran-2,3-dione by the action of methanol and in 5-aryl-4-methyl-2,3-dihydrofuran-2,3-diones by the action of aniline and N-methylaniline results in formation of, respectively, methyl 3-methyl-4-phenyl-2,4-dio

Full text of DOI:10.1023/A:1022508622558

Russian Journal of Organic Chemistry, Vol. 38, No. 10, 2002, pp. 1491 1494. Translated from Zhurnal Organicheskoi Khimii, Vol. 38, No. 10, 2002,
pp. 1544 1547.
Original Russian Text Copyright
2002 by Zalesov, Kozlov.
Decyclization of 5-Aryl-4-methyl-2,3-dihydrofuran-2,3-diones
by the Action of Nucleophiles*
V. V. Zalesov1 and A. P. Kozlov2
1
Perm State University, ul. Bukireva 15, Perm, 614600 Russia
2
Perm State Academy of Agriculture
Received March 18, 2002
Abstract Ring cleavage in 4-methyl-5-phenyl-2,3-dihydrofuran-2,3-dione by the action of methanol and in
5-aryl-4-methyl-2,3-dihydrofuran-2,3-diones by the action of aniline and N-methylaniline results in formation
of, respectively, methyl 3-methyl-4-phenyl-2,4-dioxobutanoate and 4-aryl-3-methyl-2,4-dioxobutananilides.
The reaction mechanism was studied by 1H NMR spectroscopy.
The synthesis and chemical transformations of
5-aryl-4-methyl-2,3-dihydrofuran-2,3-diones Ia Id
were reported in a limited number of publications
[1 10]. Nevertheless, the available data indicate
essentially different chemical behavior of furandiones
Ia Id as compared to their analogs having no substit-
uent in position 4, 5-aryl-2,3-dihydrofuran-2,3-diones,
which were studied in much more detail [11].
We have found that the reaction of 4-methyl-5-
phenyl-2,3-dihydrofurandione (Ia) with methanol
results in opening of the furan ring with formation
of methyl 3-methyl-2,4-dioxo-4-phenylbutanoate (II).
Likewise, aniline and N-methylaniline react with
5-aryl-4-methyl-2,3-dihydrofuran-2,3-diones Ia Id to
give 4-aryl-3-methyl-2,4-dioxobutananilides IIIa IIIe
(Scheme 1). The yields, physical properties, spectral
data, and elemental analyses of compounds II and
IIIa IIIe are given in Tables 1 and 2. On heating
under reduced pressure, ester II undergoes cyclization
to initial furandione Ia with loss of methanol mole-
cule. According to the spectral data, compounds II
and IIIa IIIe in crystal and in solution exist in the
diketone form, in contrast to analogous esters and
amides having no methyl group in the 3-position [11].
Obviously, ester II and amides III are formed
via nucleophilic attack by the alcohol or amine on the
C2 atom of the furan ring, followed by ring opening
in intermediate Int1. In the reaction of furandione Ia
Scheme 1.
I, III, R = H: R = H (a), Me (b), F (c), Cl (d); R = H, R = Me (e).
____________
*
This study was financially supported by the Russian Founda-
tion for Basic Research (project no. 01-03-32641).
Deceased.
1070-4280/02/3810-1491$27.00 2002 MAIK Nauka/Interperiodica

1492
ZALESOV, KOZLOV
Scheme 2.
Table 1. Yields, melting points, and IR and 1H NMR spectra of compounds II and IIIa IIIe
Comp.
no.
Yield,
%
1
mp,
C
IR spectrum, , cm
1H NMR spectrum (CDCl3), , ppm, (J, Hz)
II
51
64
71
Oily liquid 1743 (COOCH3), 1712 (C2 O), 1.41 d (3H, CH3, 8), 3.70 s (3H, COOCH3), 4.91 q
1675 (C4 O)
(1H, CH, 8), 7.48 s (5H, C6H5)
IIIa
IIIb
123 125
3305 (NH), 1696 br (C2 O, 1.40 d (3H, CH3, 6), 5.06 q (1H, CH, 6), 7.45 m
CONH), 1658 (C4 O)
(10H, C6H5), 8.98 s (1H, NH)
150 151
3364 (NH), 1717 (C2 O), 1690 1.38 d (3H, CH3, 7), 2.36 s (3H, CH3C6H4), 5.28 q
(CONH), 1662 (C4=O)
(1H, CH, 7), 7.41 m (9H, Harom), 8.59 s (1H,
NH) [3]
IIIca
IIId
IIIe
43
59
59
147 149
144 145
3309 (NH), 1699 (C2 O), 1.37 d (3H, CH3, 7), 4.69 q (1H, CH, 7), 7.52 m
1649 br (CONH, C4 O)
(9H, Harom), 10,33 s (1H, NH)
3346 (NH), 1731 (C2 O), 1693 1.43 d (3H, CH3, 6.5), 5.22 q (1H, CH, 6.5), 7.37 m
(CONH), 1678 (C4 O)
(9H, Harom), 8.68 s (1H, NH)
Oily liquid 3317 (NH), 1703 (C2 O), 1691 1.21 d (3H, CH3, 7), 3.18 s (3H, CH3N), 5.05 q
(CONH), 1660 (C4 O)
(1H, CH, 7), 7.25 m (10H, C6H5)
a
The 1H NMR spectrum was recorded in DMSO-d6.
Table 2. Elemental analyses of compounds II and IIIa IIIe
Found, %
Comp.
Calculated, %
Formula
no.
C
H
N
Hlg
C
H
N
Hlg
II
65.57
72.39
73.03
68.07
64.90
73.35
5.60
5.30
5.99
4.81
4.28
6.00
C12H12O4
65.45
72.58
73.20
68.22
64.67
73.20
5.49
5.38
5.80
4.72
4.47
5.80
IIIa
IIIb
IIIc
IIId
IIIe
5.05
4.60
4.50
4.61
4.63
C17H15NO3
C18H17NO3
C17H14FNO3
C17H14ClNO3
C18H17NO3
4.98
4.74
4.68
4.44
4.74
6.49
6.35
11.06
11.23
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 10 2002

DECYCLIZATION OF 5-ARYL-4-METHYL-2,3-DIHYDROFURAN-2,3-DIONES
1493
(a)
(b)
(c)
(d)
1H NMR spectra in chloroform-d at 50 C: (a) intermediate Int1, (b) intermediates Int1 Int3 (5 min after the reaction started),
(c) intermediates Int1 Int3 and ester II (10 min after the reaction started), and (d) ester II (30 min after the reaction started).
with methanol, ring opening in Int1 is likely to give
two enol intermediates Int2 and Int3 which are
characterized by similar stabilities. Proton migration
to the C3 atom in Int2 or Int3 leads to the final
product, ester II (Scheme 2).
By H NMR monitoring of the reaction of furandi-
one Ia with methanol we succeeded in detecting inter-
mediates Int1 Int3 (see figure). Immediately after the
reaction started, we observed in the 1H NMR spectrum
signals from the methyl ( 2.05 ppm, s), methoxy
( 3.35 ppm, s), and hydroxy protons ( 2.58 ppm) of
intermediate Int1 (see figure, a). After 5 min, signals
from the methyl and methoxy protons ( 1.98 and
3.85 ppm) of enol intermediates Int2 and Int1
1
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 10 2002

1494
ZALESOV, KOZLOV
appeared (b). Their intensity increased in parallel with
disappearance of the signals belonging to Int1. When
the fraction of Int1 was 27.5%, the spectrum con-
tained a doublet from methyl protons at 1.41 ppm,
REFERENCES
1. Kozlov, A.P., Cand. Sci. (Chem.) Dissertation, Perm,
1979.
2. Andreichikov, Yu.S. and Kozlov, A.P., USSR
Inventor’s Certificate no. 777030; Byull. Izobret.,
1980, no. 41.
3. Brigadnova, E.V., Maslivets, A.N., and Andreichi-
kov, Yu.S., Zh. Org. Khim., 1988, vol. 24, no. 10,
pp. 2235 2238.
4. Zalesov, V.V., Kataev, S.S., and Kozlov, A.P.,
Sbornik nauchnykh trudov Karbonil’nye soedine-
niya v sinteze geterotsiklov (Collection of Scientific
Papers Carbonyl Compounds in the Synthesis of
Heterocycles ), Saratov, 1996, part 1, p. 126.
a singlet from methoxy group at
3.70 ppm, and
a quartet from CH proton at 4.91 ppm, which cor-
respond to the final product, ester II (c). The reaction
was complete in 30 min (d).
An analogous spectral pattern was observed in the
reaction of furandione Ia with N-methylaniline with
the only difference that signals from the resulting
3,N-dimethyl-4-phenyl-2,4-dioxobutananilide (IIIe)
1
and the corresponding enol forms appeared in the H
NMR spectrum immediately after the reaction started.
5. Pimenova, E.V., Zalesov, V.V., Kataev, S.S., and
Nekrasov, D.D., Russ. J. Gen. Chem., 1997, vol. 67,
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Andreichikov, Yu.S., Available from VINITI,
no. 160-V.98, 26.05.1998.
EXPERIMENTAL
The IR spectra were recorded on Specord-80M and
UR-20 instruments from samples dispersed in mineral
oil. The H NMR spectra were obtained on RYa-2310
1
(60 MHz) and Bruker WR-80SY spectrometers in
CDCl3 or DMSO-d6 with HMDS as internal reference.
The progress of reactions was monitored, and the
purity of the products was checked, by TLC on Silufol
UV-254 plates using diethyl ether benzene acetone
(10:9:1) as eluent.
Methyl 3-methyl-2,4-dioxo-4-phenylbutanoate
(II). A solution of 1.74 g (0.01 mol) of furandione Ia
in 20 ml of methanol was heated to the boiling point,
the solvent was evaporated, the residue was refluxed
in 10 ml of methanol with addition of charcoal, the
mixture was filtered, and the filtrate was evaporated
to obtain 1.05 g (51%) of ester II as an oily liquid.
3-Methyl-4-phenyl-2,4-dioxobutananilide (IIIa).
A solution of 1.74 g (0.01 mol) of furandione Ia and
0.93 g (0.01 mol) of aniline in 20 ml of dry chloro-
form was stirred for 1 h at 20 25 C. The solvent was
removed, and the residue was recrystallized from
cyclohexane. Yield 1.72 g (64%), mp 123 125 C.
Anilides IIIc IIIe were synthesized in a similar way.
Compounds IIIa and IIId were recrystallized from
cyclohexane, and IIIb and IIIc, from methanol.
7. Kozlov, A.P. and Sazhnev, S.S. Abstracts of Papers,
Regionalnaya nauchno-prakticheskaya konferentsiya
uchenykh i spetsialistov APK (Regional Scientific
Practical Conf. of Scientists and Specialists of the
Agroindustrial Complex), Perm, 1998, p. 33.
8. Kozlov, A.P. and Sazhnev, S.S., Abstracts of Papers,
Mezhvuzovskaya nauchno-prakticheskaya konferen-
tsiya professorsko-prepodavatel’skogo sostava Perm-
skoi gosudarstvennoi farmatsevticheskoi akademii
(Interinstitutional Scientific Practical Conf. of the
Teaching Staff at the Perm State Pharmaceutical
Academy), Perm, 1998, p. 83.
9. Kozlov, A.P., Sazhnev, S.S., and Andreichi-
kov, Yu.S., Abstracts of Papers, Molodezhnaya
nauchnaya shkola po organicheskoi khimii (Youth
Scientific School on Organic Chemistry), Yekaterin-
burg, 1998, pp. 90 91.
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Nekrasov, D.D., Russ. J. Org. Chem., 1998, vol. 34,
no. 1, pp. 98 103.
11. Andreichikov, Yu.S., Gein, V.L., Zalesov, V.V.,
Kozlov, A.P., Kollenz, G., Maslivets, A.N., Pimeno-
va, E.V., and Shurov, S.N., Khimiya pyatichlennykh
2,3-dioksogeterotsiklov (Chemistry of Five-Mem-
bered 2,3-Dioxo Heterocycles), Andreichikov, Yu.S.,
Ed., Perm: Perm. Univ., 1994, pp. 5 54.
Anilide IIIb was obtained by the procedure
reported in [3].
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 10 2002