Russian Journal of Organic Chemistry, Vol. 40, No. 10, 2004, p. 1543. Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, p. 1590.
Original Russian Text Copyright © 2004 by Ilyushkin, Semichenko, Suboch.
SHORT
COMMUNICATIONS
Transformation of Hydroxyiminoacetoacetanilides
in Sulfuric Acid
D. I. Ilyushkin, E. S. Semichenko, and G. A. Suboch
Siberian State Technological University, pr. Mira 82, Krasnoyarsk, 660049 Russia
e-mail: organic@scn.ru
Received February 27, 2004
Cyclization of acetoacetanilides on heating in sul-
furic acid underlies the general procedure for synthesis
of quinolines according to Knorr [1]. However, there
are no published data on the behavior of α-hydroxy-
imino-β-oxocarboxanilides under similar conditions.
We have found that heating of hydroxyiminoaceto-
acetanilides Ia–Ic in sulfuric acid, instead of the
expected nitrosoquinolines IIa–IIc, leads to formation
of isatins IIIa–IIIc in 14 to 44% yield. Presumably,
Beckmann fragmentation of Ia–Ic gives cyanoform-
anilides IVa–IVc which are converted into the corre-
sponding isatins. The low yields of IIIa–IIIc may be
due to concurrent processes, e.g., transformation into
phenyl isocyanate.
concentrated sulfuric acid heated to 75°C, maintaining
the temperature below 85°C. The mixture was stirred
for 20 min at 80–85°C, cooled, and poured onto 200 g
of ice. The precipitate of isatin IIIb or IIIc was filtered
off, while compound IIIa was isolated by extraction
into chloroform (5×200 ml). The products were
purified as follows. Crude isatin IIIa–IIIc was
dissolved in an appropriate amount of 2 N aqueous
sodium hydroxide, 0.1 g of charcoal was added, the
mixture was stirred for 30 min at 80°C, a 1.5-fold
amount of glacial acetic acid was added, and the
mixture was filtered. Concentrated hydrochloric acid
was added to the filtrate to precipitate compound IIIa–
IIIc. Isatin (IIIa): yield 14%, yellow–red crystals,
mp 203.5°C (from EtOH) [2]. 7-Methylisatin (IIIb):
yield 44%, yellow–red crystals, mp 270°C (from
EtOH); published data [3]: mp 268–270°C. 5,7-Di-
methylisatin (IIIc): yield 14.4%, yellowish–red
crystals, mp 247°C (from EtOH); published data [3]:
mp 247–249°C.
Anilide Ia–Ic, 0.0485 mol, was added over a period
of 15 min under stirring to 20 ml (0.349 mol) of
OH
N
O
O
N
C
C
R'
R'
Me
H2SO4
N
H
N
O
The progress of reactions and the purity of products
were monitored by TLC on Silufol UV-254 plates
using ethyl acetate–chloroform (1:3) as eluent; detec-
tion under UV light. The melting points of compounds
IIIa–IIIc coincided with published data.
H
R
R
Ia–Ic
IVa–IVc
(1) H2SO4
(2) H2O
–H2O
Me
REFERENCES
O
R'
NO
O
R'
1. Knorr, L., Justus Liebigs Ann. Chem., 1886, vol. 236,
p. 69; Knorr, L., Justus Liebigs Ann. Chem., 1888,
vol. 245, p. 357.
O
N
N
H
H
R
R
2. Hantzsch, Ber., 1921, vol. 54, p. 1242.
3. Hudson, C.B. and Robertson, A.H., Aust. J. Chem., 1967,
vol. 20, p. 1521.
IIa–IIc
IIIa–IIIc
I–IV, R = R' = H (a), R = Me, R' = H (b); R = R' = Me (c).
1070-4280/04/4010-1543 © 2004 MAIK “Nauka/Interperiodica”