Organic Syntheses, Coll. Vol. 2, p.228 (1943); Vol. 13, p.36 (1933).
Thirty-five grams (0.27 mole) of hydrazine sulfate (Org. Syn. Coll. Vol. I, 1941, 309)
is suspended in 125 cc. of hot water in a 400-cc. beaker
and stirred by hand during the addition of 85 g. (0.87 mole) of potassium acetate (Note 1)
. The mixture is boiled five minutes and then cooled to about 70°; 75 cc. of alcohol
is added, and the solid is filtered with suction and washed with 75 cc. of hot alcohol
. The filtered hydrazine solution is saved for the next step.
In a 1-l. flask
fitted with a stirrer
and reflux condenser
, 50.5 g. (0.25 mole) of technical 2,4-dinitrochlorobenzene
is dissolved in 250 cc. of alcohol
; the hydrazine solution is added, and the mixture is refluxed with stirring for an hour. Most of the product separates during the first ten minutes (Note 2)
; it is cooled well, filtered, and washed, once with 50 cc. of warm alcohol
(60°) to remove unchanged halide and then with 50 cc. of hot water. The solid weighs 30 g.
and melts at 190–192°
with evolution of gas (Note 3)
; it is pure enough for most purposes. By distilling half the alcohol from the filtrate a less pure second crop is obtained; this is recrystallized from n-butyl alcohol (30 cc. per g.) (Note 4)
. The total yield is 40–42 g.
per cent of the theoretical amount) (Note 5)
Considerable heat is evolved during the separation.
The melting point is not sharp; in the capillary tube
the sample shrinks about 10° below the melting point.
For recrystallization, n-butyl alcohol
is the best solvent in spite of the large amount required, but tetralin, pyridine, or dioxane (10 cc. per g.)
may be used where large quantities are involved. Fortunately, most of the material as prepared does not need further purification.
Complete evaporation of the filtrate yields a gummy residue; the amount of dinitrochlorobenzene
present is too small to justify recovery.
These directions have been used equally successfully with twice, and with five times, the amounts specified.
Chemical Abstracts Nomenclature (Collective Index Number);
sodium acetate (127-09-3)
sodium hydroxide (1310-73-2)
n-butyl alcohol (71-36-3)
hydrazine hydrate (7803-57-8)
Hydrazine, (2,4-dinitrophenyl)- (119-26-6)
Hydrazine sulfate (10034-93-2)
potassium acetate (127-08-2)
picryl chloride (88-88-0)
hydrazine acetate (7335-65-1)
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