280
YUTILOV et al.
Raney nickel appeared to be the most effective in
Reduction of IV with hydrazine hydrate in 0.5
6.0% aqueous NaOH solutions at 30 50 C. A 10.0-g
(23.4-mmol) portion of IV was mixed with a solution
of 0.5 6 g of NaOH in 100 ml of water, and 2.0 g
of a catalyst (Raney nickel, 5% Pd/C. 5% Pt/C,
5% Pd/BaSO4, or 5% Pt/BaSO4) was added. Then
40 ml (0.8 mol) of 98 100% hydrazine hydrate was
added in portions with vigorous stirring and heat-
ing to 30 50 C. After heating for 3 4 h under these
conditions, the catalyst was filtered off, and the fil-
trate was acidified with 2% H2SO4 to pH 6. The pre-
cipitate was filtered off, washed with a small amount
of water, and dried.
aqueous NaOH at a 25-fold excess of hydrazine hy-
drate. In this case, the yield of II is the highest, and
its melting point and chromatographic characteristics
are identical to those of an authentic sample [7].
At a smaller (15-fold) excess of hydrazine hydrate,
or with an alkaline alcoholic solution used, the reduc-
tion of IV to II is incomplete.
EXPERIMENTAL
The purity of II was checked by high-velocity
microcolumn liquid chromatography on a Milikhrom
device equipped with a UV detector. A 64 2-mm
stainless steel column ( 3000 TP) was packed with
Separon (particle diameter 4 m). The best system for
elution of II was acetone water hexane, 86 : 12 : 2
(by volume). The chromatographing conditions were
as follows: sensitivity range 1.6, measurement time
CONCLUSIONS
(1) Preparative procedures were suggested for the
reduction of 3-(3"-nitrobenzoylamido)-1-(2 , 4 , 6 -tri-
chlorophenyl)pyrazol-5-one with hydrogen or hy-
drazine hydrate in aqueous NaOH in the presence of
Raney nickel, 5% Pd/C, 5% Pt/C, 5% Pd/BaSO4, or
5% Pt/BaSO4 to obtain 3-(3"-aminobenzoylamido)-1-
(2 , 4 , 6 -trichlorophenyl)pyrazol-5-one.
0.15 s, wavelength
in the STOP mode 280 nm,
1
eluent feed rate 200 l min , and paper feed rate
1
1800 mm h . The retention time of II under these
conditions was 48 s.
(2) A procedure was developed for prompt anal-
ysis of the quality of the amine with a Milikhrom
liquid chromatograph.
Reduction of IV with hydrogen in 0.5 3.0%
aqueous NaOH solutions at 20 C. A 10.0-g (23.4-
mmol) portion of IV was dissolved in 200 ml of
water containing 1 6 g (25 150 mmol) of NaOH and
subjected to catalytic hydrogenation in the presence
of a catalyst (Raney nickel, 5% Pd/C, 5% Pt/C, 5%
Pd/BaSO4, or 5% Pt/BaSO4). To do this, the reaction
vessel was first purged with nitrogen to remove air,
and then nitrogen was replaced with hydrogen. The re-
duction was performed at 25 C and an H2 pressure of
1 atm with continuous stirring until the hydrogen up-
take ceased (200 ml). The catalyst was filtered off, and
the filtrate was acidified with a solution of hydrochlo-
ric or acetic acid to pH 6. The precipitate was filtered
off, washed with a small amount of water, and dried.
REFERENCES
1. Theys, R.D. and Sosnovsky, Y., Chem. Rev., 1997,
vol. 97, no. 1, pp. 83 132.
2. Arient, J. and Dostal, J., Chem. Listy, 1988, vol. 82,
no. 12, pp. 1254 1281.
3. US Patent 3812145.
4. US Patent 2600788.
5. US Patent 3823156.
6. JPN Appl. 58-140075.
7. USSR Inventor’s Certificate, no. 1441734.
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 78 No. 2 2005