posted January 17, 2000 03:14 PM            

Here is what I could find for the moment:
Anhydrous hydrazine may be obtained by refluxing 100% hydrazine hydrate (
or the 95% material which has previously been allowed to stand overnight
over 20% w/w of potassium hydroxide and filtered) with an equal weight of
sodium hydroxide pellets for 2 hours and then distilling in a slow stream
of nitrogen: b.p. 114-116 degrees C. Distallation in air may lead to
explosion.
N.B. Hydrazine is a suspected carcinogen handle with appropriate
precautions. Also extremely corrosive so use gloves & safety spectacles.
hydrazine hydrate is available in 60% w/w and 98-100 % w/w concentrations
commercially.
60% hydrazine hydrate is concentrated as follows
A mixture of 150g(144ml ) of the solution and 230ml of xylene is ditilled
from a 500ml round bottomed flask through a well lagged Hempel(or other
efficient fractionating) column in a nitrogen atmosphere. All the xylene
passes over with about 85 ml of water.
Upon distillation of the residue, about 50g of 90-95 per cent hydrazine
hydrate are obtained.

Oh, and do I need to try out the site ban feature to make an example of newbies?

posted January 18, 2000 03:16 AM            

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"The knowledge that they fear is a weapon to be used against them." www.50megs.com/nbk2000

posted January 20, 2000 04:40 AM            

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posted January 27, 2000 09:01 AM            

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HYDRAZINE SULFATE

2 NH3 + NaOCl--> NH2NH2 + H2O + NaCl

Prepared by ROGER ADAMS and B. K. BROWN. Checked by J. B. CONANT
and W. L. HANAWAY.

1. Procedure

A NORMAL solution of sodium hypochlorite is prepared as follows:
in a 5-l. round-bottom flask are placed 1800 g. of sodium
hydroxide solution (300 g. of sodium hydroxide to 1500 g.
of water) and 1500 g. of ice. Chlorine gas is then passed into
the solution until it has gained in weight approximately 213 g.
During this addition, the solution must be kept thoroughly
cooled with ice, in order that chlorates will not be formed.
After all the chlorine has been passed in, it is necessary to be
certain that the mixture is slightly alkaline, since any excess
of free chlorine in the solution prevents the formation of hydrazine.

In a 14-inch evaporating dish are placed 1500 cc.
of c. p. ammonia water (sp. gr. 0.90), 900 cc. of distilled water,
375 cc. of 10 per cent gelatine solution, and 1200 cc.
of the normal sodium hypochlorite solution prepared as above.
This mixture is heated as rapidly as possible and boiled down
until one-third of the original volume is left. This solution
is then cooled thoroughly with ice and filtered with suction,
first through two layers of toweling and then through one
thickness of ordinary filter paper over cloth, in order to remove
finely divided solid impurities. The solution is then placed
in a precipitating jar, and cooled down thoroughly (0'0) with ice
and salt; 10 cc. of concentrated sulfuric acid for each 100 cc.
of solution are gradually added with constant stirring.
A precipitate of hydrazine sulfate (NH2NH2<.>H2SO4) forms.
The mixture is allowed to stand in the cold for a few hours in order
to complete the precipitation, and is then filtered by suction in the
usual way and washed with cold alcohol. The yield varies from 53 g.
to 58 g. per 1500 cc. of ammonia water (34-37 per cent of the
theoretical amount). The product is perfectly white and crystalline,
and satisfactory for almost any purpose. If an absolutely pure
product is desired, it must be recrystallized from water.
For every 21 g. of crude product, 100 g. of boiling water are used.
If the crude hydrazine is brown, it is advisable to use a little
bone-black. After the mixture has been filtered and cooled to 0'0, 19 g.
of pure white crystals are obtained.

2. Notes

In the preparation of the sodium hypochlorite solution it is quite
necessary that the mixture be kept cold and be alkaline to red
litmus paper at the end of the reaction, if good yields of hydrazine
are to be obtained.

Since iron is an anti-catalyzer, it is necesssary{sic} to use
distilled water throughout the process.

As a viscolizer, a substance such as starch, glycerol, glue or
gelatine may be used; the last, however, gives by far the
most satisfactory results.

In order to obtain a pure white hydrazine sulfate as the
first precipitate, it is necessary to cool the hydrazine solution
thoroughly and filter it twice before the sulfuric acid is added.
Moreover, the sulfuric acid must be added slowly and with stirring.
If these conditions are not followed, material containing
brown particles results.

The mother liquor obtained from the crystallized hydrazine
sulfate contains a small amount of hydrazine. If 200 g.
of copper sulfate are dissolved in water and added to 10 l.
of the filtrates from the above processes, a light-blue crystalline
precipitate of the double salt of copper sulfate and hydrazine
sulfate will be formed after ten hours. This salt, when suspended
in ten times its weight of distilled water and treated with hydrogen
sulfide, decomposes into copper sulfide and hydrazine sulfate.
After the copper salt has been filtered off, the solution
is concentrated until the hydrazine sulfate crystallizes.
The yield of product is small, so that it is hardly advisable
to undertake this recovery in the laboratory.

It is possible for one man, simultaneously evaporating six dishes
of the hydrazine mixture, to turn out from 20 to 25 runs in nine hours.
The time for the evaporation of a solution, such as is mentioned
in the experimental part, with a four-flame Bunsen burner, is two to
three hours; if the evaporation is carried out more slowly than this,
the yield of product is distinctly diminished.

3. Other Methods of Preparation

Hydrazine salts have been prepared by the action of hypochlorites on
ammonia[1] or urea;[2] by the hydrolysis of salts of sulfohydrazimethylene
disulfonic acid;[3] by the hydrolysis of triazoacetic acid;[4] by the
reduction of diazoacetic ester;[5] by the reduction of nitroguanidine
followed by hydrolysis;[6] by the reduction of the nitroso derivatives
of hexamethylene tetramine;[7] by the reduction of nitrates or nitrites
with zinc in neutral solution;[8] by the action of sodium bisulfite
on hyponitrous acid followed by reduction;[1b] by the reduction
of K2SO3N2O2;[2b] by the action of ammonia on dichlorourea;[3b]
by the reduction of nitrosoparaldimin;[4b] by the action of copper
sulfate on ammonia at high temperatures;[5b] by the reduction of
methylene diisonitrosoamine;[6b] by the hydrolysis of the addition
product of diazoacetic ester and fumaric or cinnamic esters.[7b]

[1] D. R. P. 192,783; Chem. Zentr. 1908 (I), 427; Chem. Ztg. 31, 926
(1907); D. R. P. 198,307; Chem. Zentr. 1908 (I), 1957; Eng. Pat.
22,957; C. A. 2, 1999 (1908); U. S. Pat. 910,858; C. A. 3, 1065
(1909); French Pat. 382,357; C. A. 3, 2358 (1909); Ber.
40, 4588 (1907); Laboratory Manual of Inorganic Preparations,
by A. B. Lamb, Harvard University, Cambridge, Mass.

[2] J. Russ. Phys. Chem. Soc. 37, 1 (1905); Chem. Zentr. 1905
(I) 1227; D. R. P. 164,755; Frdl. 8, 53 (1905); French Pat. 329,430;
J. Soc. Chem. Ind. 22, 1063 (1903); Chem. Zentr. 1905 (I) 1227.

[3] D. R. P. 79,885; Frdl. 4, 26 (1895); Ber. 28, 2381 (1895).

[4] Ber. 20, 1632 (1887); Chem. News 55, 288 (1887); D. R. P. 47,600;
Frdl. 2, 554 (1889); J. prakt. Chem. (2) 39, 27 (1889).

[5] Ber. 27, 775 (1894); 28, 1848 (1895); D. R. P. 58,751; Frdl. 3, 16
(1891); D. R. P. 87,131; Frdl. 4, 28 (1896).

[6] Ann. 270, 31 (1892); D. R. P. 59,241; Frdl. 3, 16
(1891); Eng. Pat. 6,786; J. Soc. Chem. Ind. 11, 370 (1892).

[7] D. R. P. 80,466; Frdl. 4, 27 (1895); Ann. 288, 232 (1895).

[8] Eng. Pat. 11, 216; J. Soc. Chem. Ind. 14, 595 (1895). [1b] Ber.
33, 2115 (1900); Ann. 288, 301 (1895).

[2b] Ber. 27, 3498 (1894).

[3b] J. Chem. Soc. 95, 235 (1909); Chem. News 98, 166 (1908).

[4b] Ber. 23, 752 (1890).

[5b] Chem. News 66, 223 (1892).

[6b] Ber. 27, 3292 (1894);

[7b] Ber. 21, 2637 (1888).

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