TETRAALKYLAMMONIUM SALTS OF NAPHTHIMIDE
413
naphthimides with dibromoalkanes under the condi-
tions of phase-transfer catalysis, observed hydrolysis
of bromoalkylnaphthimide formed in the first step and
a decrease in the yields of the desired bisnaphthimides
stirring on a water bath at 90 C for 18 h. The reaction
product was isolated as described above. Tetrahexyl-
ammonium iodide was obtained as colorless plates;
yield 55.2 g (78%), mp 132 134 C.
[from 66% (1,6-dibromohexane) to 24% (1,3-dibromo-
Tetraoctylammonium salts of naphthimides IIa
IIh (Table 2). Appropriate finely dispersed naphth-
imide (1.5 mmol) was mixed with a 5% NaOH aque-
ous solution (50 ml) and a solution of tetraoctylammo-
nium iodide (1 mmol) in benzene (50 ml). The reac-
tion mixture was vigorously stirred at room tempera-
ture for 2 h and filtered. The organic layer was sepa-
rated, washed with water to neutral reaction, and dried
with sodium sulfate; the solvent was distilled off.
The aqueous solution was acidified, and unchanged
naphthimide was regenerated.
propane)] with decreasing length of the hydrocarbon
chain in the alkylating agent. At the same time, alkyl-
ation of tetraoctylammonium salts of 4-chloro- (IId)
and 4-nitronaphthimide (IIf) in benzene proceeds
without hydrolysis, with nearly quantitative yields
(
90 95%) of 4-chloro- (IVa IVc) and 4-nitrobis-
naphthimides (IVd IVf).
IId, IIf
Br(CH ) Br, PhH, 40 C
R NBr
4
2
n
O
N
O
N
O
Tetrahexyl- and tetrabutylammonium salts of
naphthimides IIi IIr. Procedure A. Appropriate
finely dispersed naphthimide (1.5 mmol) was mixed
with 5% NaOH aqueous solution (50 ml) and a solu-
tion of tetrahexyl- or tetrabutylammonium iodide
(
4)
Y,
(CH2)n
Y
O
VIa VIf
(
1 mmol) in benzene (50 ml). The reaction mixture
IV, Y = Cl, n (a) 3, (b) 4, (c) 6; Y = NO , n (d) 3,
e) 4, and (f) 6.
2
was vigorously stirred at room temperature for 2 h,
filtered, and the organic layer was separated. Then the
treatment of the organic phase with aqueous alkaline
solution of naphthimide of the same concentration was
repeated under similar conditions two times (tetra-
hexylammonium salts IIi IIo) and five times (tetra-
butylammonium salts IIp IIr). Further treatment of
the organic and aqueous layers was performed as
described above.
(
EXPERIMENTAL
1
The H NMR spectra were recorded on a Bruker
WM-400 device (DMSO-d , TMS internal reference).
The reaction progress and purity of the resulting com-
pounds were monitored by thin-layer chromatography
TLC) using Silicagel 60 F254 plates (Merck), with
subsequent UV development.
6
(
Procedure B. After the first extraction of approp-
The starting naphthimides Ia Ih were obtained by
riate naphthimide anion (procedure A), the reaction
the procedure presented elsewhere [16]; the required
(
mixture was mixed with AgNO (0.34 g) or Pb(NO )
3
3 2
0.1 M) solution of perchloric acid in glacial acetic
(0.66 g), and the precipitate was filtered off. Further
acid was prepared; the actual content of perchloric
acid was determined by titration with sodium biphtha-
late [17].
treatment of the organic and aqueous layers was per-
formed as in procedure A.
To determine the molecular weights of salts IIa
IIr, a portion of salt IIa IIr (0.2 g) was dissolved in
acetic acid (25 ml), two drops of Crystalline Violet
solution were added, and the resulting solution was
Tetraoctylammonium iodide. Octylamine (26 g),
octyl iodide (168 g), and potassium carbonate (55 g)
were heated with stirring on a water bath at 90 C for
20 h. After cooling, water was added to the reaction
titrated with a 0.1 M HClO solution up to change
4
mixture to dissolve inorganic salts, and the product
was extracted with chloroform. The organic layer was
separated, washed several times with a 10% aqueous
ammonia solution and with water, and then dried with
sodium sulfate. The solvent was distilled off, and after
recrystallization from ethanol tetraoctylammonium
iodide was obtained as colorless plates; yield 84 g
of the solution color from violet to blue-green. The
molecular weight of compounds IIa IIr was evaluated
from the following expression:
M = m 1000/Vacm,
where m is the weighed portion of salt IIa IIr (g),
(70%), mp 121 122 C.
c
is the concentration of HClO solution (M), and
m
a
4
Tetrahexylammonium iodide. Trihexylamine
32.4 g) and hexyl iodide (38.2 g) were heated with
V is the volume of perchloric acid consumed in titra-
tion (ml).
(
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 79 No. 3 2006