SYNTHESIS AND TRANSFORMATIONS OF 3-ARYL-5-DICHLOROMETHYL-...
1701
Thus, we have investigated the reaction of chlorine-
containing 2-aza-1,3-dienes I and II with hydrazine-
hydrate. This reaction results in the formation of
substituted 1,2,4-triazoles with dichloromethyl group,
and we used the latter for further functionalization with
the aim of the synthesis of biologically active substances.
[1,5-a:1',5'-d]pyrazines (XIa–XId). To a suspension
of 0.025 mol of a compound VIIIa–VIIIc in 15 ml of
anhydrous THF was added 0.1 mol of either
morpholine, or piperidine, or pyrrolidine, or diethyl-
amine, and the mixture was stirred at 20–25°C for
24 h. The resulting precipitate was filtered off, washed
with water and compounds XIa–XId were purified by
recrystallization.
EXPERIMENTAL
The IR spectra were recorded on a Vertex 70
spectrometer from tablets with KBr. The H NMR
spectra were taken on a Varian VXR-300 instrument
from solutions in DMSO-d6 with TMS as internal
reference.
1
N-[(3-Aryl-1H-1,2,4-triazol-5-yl)methyliden]benzyl-
amine (XIIa, XIIb). To a suspension of 0.025 mol of
a compound VIIIa or VIIIb in 15 ml of anhydrous
THF was added 0.075 mol of benzylamine, the mixture
was stirred at 20–25°C for 24 h. The resulting
precipitate was filtered off, washed with water, and
obtained compound XIIa or XIIb was purified by
recrystallization.
3-Aryl-5-dichloromethyl-4,5-dihydro-1H-1,2,4-
triazoles (VIIa, VIIb). To a solution of 0.06 mol of
hydrazine-hydrate in 10 ml of anhydrous dioxane over
0.5 h was added dropwise with stirring a solution of
0.01 mol of a compound Ia or Ib in 20 ml of dioxane.
The mixture was stirred for 12 h at 20–25°C, the
hydrazine hydrochloride was filtered off, and dioxane
was removed in a vacuum at 40°C. The residue was
treated with water, the precipitate formed was filtered
off, washed with water, and dried in a vacuum (1 mm
Hg) at 40°C for 1 h. The compounds VIIa and VIIb
obtained were analyzed without further purification.
2-[(3-Aryl-1H-1,2,4-triazol-5-yl)methyl]malonic
nitrile (XIIIa, XIIIb). To a solution of 0.003 mol of a
compound VIIIb or VIIIc in 25 ml of ethanol was
added 0.003 mol of malonodinitrile, 1.4 ml of acetic
acid, and 0.2 ml of piperidine, and the mixture was
refluxed for 24 h. The solvent was removed in a
vacuum, the residue was treated with water, the
precipitate formed was filtered off, washed with water,
and obtained compound XIIIa or XIIIb was purified
by recrystallization.
3-Aryl-5-dichloromethyl-1H-1,2,4-triazoles (VIIIa–
VIIIc). a. To a solution of 0.01 mol of a compound
IIa–IIc in 20 ml of anhydrous THF at 5°C was added
0.033 mol of hydrazine hydrate, the mixture was
stirred at 20–25°C for 12 h, the precipitate was filtered
off, the solvent was removed in a vacuum. To the
residue was added 100 ml of water, the precipitate
formed was filtered off. The obtained compounds
VIIIa–VIIIc were purified by recrystallization.
Methyl and ethyl 3-(3-aryl-1H-1,2,4-triazol-5-
yl)-2-cyanoacrylates (XIVa, XIVb). To a solution of
0.002 mol of a compound VIIIb or VIIIc in 30 ml of
ethanol was added 0.002 mol of methyl or ethyl
cyanoacetate, 1 ml of acetic acid, and 0.1 ml of
piperidine, and the mixture was refluxed for 72 h. The
solvent was removed in a vacuum, the residue was
treated with water, the precipitate formed was filtered
off, washed with water, and obtained compound XIVa
or XIVb was purified by recrystallization.
b. To a solution of 0.005 mol of freshly prepared
sample of compound VIIa or VIIb in 50 ml of dioxane
was added 0.05 mol of manganese dioxide. The
mixture was refluxed for 2 h, the precipitate was
filtered off and washed with hot dioxane. The solvent
was removed in a vacuum, and the residue was treated
with water (100 ml). The precipitate was filtered off,
and the formed compound VIIIa or VIIIb, respect-
tively, was purified by recrystallization from 2-pro-
panol. Yield 59–66%. Mixed samples of compound
VIIIa or VIIIb obtained by the methods a and b
showed no depression of the melting points, the
respective IR and 1H NMR spectra were identical.
3-Alkyl-5-[(3-aryl-1H-1,2,4-triazol-5-yl)methyl]-
2-thioxo-1,3-tiazolidin-4-ones (XVa–XVc). To a
solution of 0.0022 mol of a compound VIIIa–VIIIc in
20 ml of ethanol was added 0.0022 mol of N-
alkylrhodanine in 10 ml of ethanol, 1 ml of acetic acid
and 0.1 ml of piperidine, and the mixture was refluxed
for 72 h. The solvent was removed in a vacuum, the
residue was treated with water, the precipitate formed
was filtered off, washed with water, and obtained
compound XVa–XVc was purified by recrystal-
lization.
2,7-Diaryl-5,10-di(morpholino, piperidino, pyr-
rolidino, diethylamino)-5H,10H-bis[1,2,4]-triazolo-
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 80 No. 8 2010
Sokolyuk
