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Author: Subject: Hydrazine
Rosco Bodine
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[*] posted on 21-5-2007 at 10:35


@ garage chemist

About the urea method , I was wondering if you tried using the urea as a slurry like the patent described , instead of as a 50% solution .....thinking that perhaps the water content for a 50% solution might be what is causing the stability problem due to the competing reaction of the chlorine with water .

Also I have been thinking more about the possibility of using TCCA plus CaCl2 in an analogous manner as the salt plus TCCA reaction for producing chlorine , still thinking that perhaps simply adding NaOH solution dropwise to a stirred mixture of TCCA suspended in CaCl2 , may result in a strong solution of bleach over precipitated calcium cyanurate .

What I was thinking was a solubility driven reaction
summarized here :

[ 2 TCCA + 3 CaCl2 ----> 6 Cl2 + Ca3(OCN)6 ]

[ 12 NaOH + 6 Cl2 -----> 6 NaOCl + 6 NaCl + 6 HOH ]

2TCCA + 3CaCl2 + 12NaOH ----> 6NaOCl + 6NaCl + Ca3(OCN)6 + 6 HOH

I was looking at the possibility of using sodium dichloroisocyanurate in a similar way but realized the
equation doesn't quite balance .....so I will have to give that one some more thought .


[Edited on 21-5-2007 by Rosco Bodine]
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[*] posted on 21-5-2007 at 12:58


Having recently acquired 5kg of 70% Ca(OCl)2 from ebay, and with TCCA being significantly more expensive than it, I will use the calcium hypochlorite as the chlorine source in my hydrazine experiments.

TCCA only liberates hypochlorite when reacted with strong NaOH solution. I dont know if Ca(OH)2 solution is alkaline enough for it.
Also, if you have rather concentrated solutions of calcium salts, you cant simply precipitate it by adding an anion that forms an insoluble calcium salt. It will turn into goop instead, probably making the kneading process I described for getting NaOCl from Ca(OCl)2 necessary as well.

Maybe someone else has the time to do experiments on how to obtain strong NaOCl solution from TCCA, as I dont have it.
It would definately be interesting.




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Rosco Bodine
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[*] posted on 21-5-2007 at 13:37


I think the TCCA reaction would work , but very slowly
due to low solubility of the TCCA and especially because
heat could not be used to drive the reaction .

And yeah the voluminous precipitate of calcium salts is usually a headache , requiring a filter press or a
"twisting the chesecloth" manipulation to squeeze the
solution from the mush .

The alternative is generating free chlorine and chlorinating a cold NaOH solution . So it is going to be something of a nuisance in one way or the other ,
by either approach .

I think if the calcium cyanurate as a byproduct was a goal it would probably be easier just to go with a chlorine generation scheme for the NaOH , and then neutralize
the HCl and cyanuric acid residue in the chlorine generator with washing soda or bicarbonate , and then
add CaCl2 solution to precipitate the calcium cyanurate .

Anyway it was just an idea , but I suppose the manipulation difficulties and temperature limitations
would make it impractical , even though on first thought it seems like a good idea .
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biggrin.gif posted on 4-6-2007 at 19:52
Hydrazine Amalgam


Just when you thought you knew a few things about hydrazine ....hmmm ,
then you learn it thinks it is a metal ,
and sooooo of course it forms amalgams :D

This is really pretty neat , totally wierd ,
and possibly also very useful .

[Edited on 4-6-2007 by Rosco Bodine]

Attachment: US3301773 Hydrazine from Hydrazine Amalgams via Electrolysis.pdf (271kB)
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[*] posted on 4-6-2007 at 20:17


Like ammonium amalgam, except more stable it appears.
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[*] posted on 2-7-2007 at 03:16


Does anyone here know anything on how to make alminium hydrazine?
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[*] posted on 23-7-2007 at 13:11
More on Hydrazine


From Ye old rhodium apothecary
http://designer-drug.com/pte/12.162.180.114/dcd/chemistry/hy...

Of course you can always just buy the Sulfate, just don't pay more than 15 cents per gram ;) ( extra with shipping )
http://www.advance-scientific.net/Properties.asp?code=H1019+...

P.S.
@ tito-o-mac
aluminum hydrazine is not a componud , it is a suspension of aluminum dust and anhydrous hydrazine.
Hydrazine hydrate will slowly combine the aluminum with the water into aluminum hydroxide releasing
hydrogen gas until all that remains is anhydrous hydrazine over the aluminum hydroxide precipitate.
Not good if this happens in a closed container having hydrogen under pressure over anhydrous hydrazine.
VERY - B I G - B O O M , house falls back to earth as blizzard of sawdust.

_______________________________________________________________

U P D A T E

Note that my assertion above may be unfounded. Draw your own conclusions.
Quoted from page 392 of Corrosion of Aluminium
posted here _
http://www.sciencemadness.org/talk/viewthread.php?tid=8706&a...

Pure hydrazine and its derivatives monomethylhydrazine (MMH) CH3NHNH2 and
dimethylhydrazine (DMH) (CH3)2NNH2 have no action on aluminium in a wide
range of temperatures between -196 and +27 ºC [14].
Hydrazine solutions have no action on aluminium; the annual decrease in thickness
in solutions at 5 and 10% is below 1 mm.
Hydrazine and its derivatives are not decomposed or altered in contact with aluminium
alloys [15].
This makes it possible to manufacture the tanks of rockets in aluminium alloys
such as 6061. Tests have shown that this alloy is not prone to stress corrosion in
hydrazine [16].

[15] Van der Wall E.M., Suder J.K., Beegle R.L., Cabeal J.A., Propellant/Material compatibility
study, AFRPL, report TR-71-741.
http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=0736464&Locat...
[16] Gilbreath P., Adamson M.J., The stress-corrosion susceptibility of several alloys in hydrazine
fuels, NASA, report TN D-7604, February 1974.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/1974000...

Edited on 25-12-2007
- - - - - - - - - - - - - - - - - - - -

More Curious observations from various sources _

Investigations on the reaction between aluminum and hydrazine have produced
discordant results. However, at least under some conditions, hydrazine has
caused corrosion of aluminum. This corrosion is dependent on the aluminum alloy,
the hydrazine purity and the temperature.

In normal environments aluminum is covered by a protective oxide layer. The
solubility of this oxide in water is very low but is increased in acidic or alkaline
solutions. The oxide is very hard to reduce. For example,the free energy change,
for the reaction 3 N2H4 + 2 Al203 = 3N2 + 6H20 + 4Al, is +321 Kcal. With such a
high positive free energy change, the reduction by hydrazlne is not found.

The solubility of aluminum or aluminum oxide in hydrazine appears to be very slight.
However, when hydrazine was stored in 2014 aluminum, a precipitate was
observed containing aluminum and copper. This dissolution and precipitation
appears to be similar to corrosive reactions in water where there is local solubility
followed by precipitation of the dissolved product.


A commonality exists between solutions of water and carbon dioxide in hydrazine
in that both are sources of protons _

H20 + N2H4 = N2H5(+) + OH(-)

CO2 + N2H4 = H2N2HCOO(-) H(+)

The latter product, carbazic acid, is probably more correctly characterized in
excess hydrazine as the hydrazinium salt, H2N2HCOO(-)N2H5(+). The hydrazinium
ion, N2H5(+), in hydrazine is the analog in properties of the hydronium ion, H30 +,
in water. Simplistically. a measure of the hydrazinium ion concentration may be
calculated for systems containing the two impurities by using the equilibrium
constant for reaction (1), K298 = 8.5X10-7, s and assuming for reaction (2) that
carbazic acid is a strong acid and the CO2 reaction with N2 H4 is complete. Thus,
for small amounts of water, the hydrazinium ion will be proportional to the
half-power of the water concentration and at a 1 percent impurity level would be
7×10 -4 M. Assuming complete ionization, the hydrazinium ion concentration in
reaction (2) is directly proportional to the carbon dioxide impurity

It is expected that the hydrazine salt of carbazic acid will ionize in hydrazine as
N2H5(+) and N2H3C00(-). If the N2H5(+) ion is the reactive or catalytic species
in the carbazic acid catalyzed decomposition of hydrazine, this would be in
agreement with the previous observation that, of the other additives tested, only
water increased the decomposition rate.


[Edited on 3-1-2008 by franklyn]
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[*] posted on 23-7-2007 at 14:32


Hydrazine is basic, eh? That would corrode aluminum quite nicely in the presence of water, yes!

Tim




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[*] posted on 24-7-2007 at 07:57


@tito-o-ma, mess around w/anhydrous hydrazine at age 14 and you won't make it out or four teens.

CARCINOGEN.
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[*] posted on 25-7-2007 at 02:45
Much more on Hydrazine


The original 1906 Raschig process combining aqueous ammonia and hypochlorite
in gelatin remains the most amenable to the small scale production of Hydrazine.
A detailed outline on how to do this yourself is here below.
In 1907 Olin modfied this process for industrial scale to be done in two steps to
eliminate the need for gelatin. Other different Industrial processes that have
also seen use are , Hoffman (Urea) process , Bayer (Ketazine) process, Atofina
(Peroxide) process , brief descriiptions are in the attached *.zip file
as well as physical data on ammonia and hydrazine.
More references are below here.

__________________________


1. Preparation of NaClO
A NORMAL solution of sodium hypochlorite is prepared as follows: in a 5-liter
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.


Preparation of Hydrazine Sulfate or the hydrate


2. Procedure
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 precipitate 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.


3. 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.

_______________________________________________________________


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).

__________________________________________________________


A microwave process
http://www.rsc.org/publishing/journals/article.asp?doi=f1972...

J. Chem. Soc., Faraday Trans. 1, 1972, 68, 315 - 322, DOI: 10.1039/F19726800315

Decomposition of ammonia in a microwave discharge
by R. Barker

Abstract
Ammonia is decomposed in a microwave discharge to give hydrazine, nitrogen and hydrogen. Product yields have been measured as a function of ammonia flow-rate, pressure, power input, temperature and added allyl alcohol and propylene. Hydrazine yields are increased with these additives, although the effect falls off at high powers, whereas gas yields (which approximate to the overall ammonia decomposition) are not appreciably affected. Kinetic and analytical evidence shows that the effect of allyl alcohol in increasing the hydrazine yield is by scavenging H atoms and that few NH2 radicals are scavenged. The remaining hydrazine destruction mechanism (particularly at high power) is probably electron-induced.


__________________________________________________________

.

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Rosco Bodine
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[*] posted on 25-7-2007 at 04:16


Quote:
Originally posted by franklyn
The original 1906 Raschig process combining aqueous ammonia and hypochlorite
in gelatin remains the most amenable to the small scale production of Hydrazine.


On which planet ? Not on this earth , that's for damn sure .

Unbelievable , *absolute* crap ( without *any* qualification ) . PERIOD .
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[*] posted on 25-7-2007 at 16:43
Urea


Roscoe, I'll agree with you on one point. The Raschig process will not be as
efficient as urea/gelatine/calcium hypochlorite process. Besides, I don't care
for the smell of ammonia !




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[*] posted on 25-7-2007 at 21:29


Yeah , the literature really needs to be updated with regards to what are convenient lab methods based on urea . That old ammonia process keeps coming up like a bad penny even though it is way less productive and
way more cumbersome . It gives the impression that the
powers that be simply don't want it well known just how easy it is to make hydrazine ....so they misdirect and misinform ....answering inquiries with directions to
the long and winding road rather than the quick and easy path .
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[*] posted on 25-7-2007 at 22:09


Quote:
Originally posted by Rosco Bodine
Yeah , the literature really needs to be updated with regards to what are convenient lab methods based on urea . That old ammonia process keeps coming up like a bad penny even though it is way less productive and
way more cumbersome . It gives the impression that the
powers that be simply don't want it well known just how easy it is to make hydrazine ....so they misdirect and misinform ....answering inquiries with directions to
the long and winding road rather than the quick and easy path .

More likely the "powers that be" just don't care about better small-scale procedures because institutionally affiliated chemists buy hydrazine that was made on an industrial scale. A lot of Inorganic Syntheses and Organic Syntheses, particularly earlier volumes, describes materials that usually enter the laboratory via delivery service today.




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[*] posted on 26-7-2007 at 03:12


Org.Syn. came into existance when there was no US manufacturing chemical industry and researchers were dependent on German suppliers. This supply line was disrupted by WWI. This resulted in the creation of Eastman's organic-chemical manufacturing operations in Rochester and also in the decision by Roger Adams and the other founders of Org.Syn. that a need existed for reliable and checked preparative procedures to be collected and regularly published so that researchers could prepare their own reagents.

The first annual volume appeared in 1921.

Over the years and decades that followed the emphasis of Org.Syn.'s editorial policy shifted. American researchers were no longer forced to prepare their own reagents. The careful preparative detail and the checking procedures remained, but the target compounds became more a matter of current trends in synthesis rather than basic building blocks. You can see the scale of the preparations roll back over time as well.

No one at Org.Syn. (or Wiley) is suppressing anything about hydrazine, it's simply that the procedure has not been updated since the 1920s and perhaps no one has submitted a hydrazine prep using the urea route. Org.Syn. does publish novel preparations of previously covered reagents from time to time.
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[*] posted on 26-7-2007 at 07:14


Maybe they just weren't paying attention ,
or else the publications rely entirely on voluntary
contributors .....and nobody gave :D

Somehow the "newer" (of that time) practical lab method fell through the cracks and didn't make it into the more prominent general references , though there is a sprinkling of references in chemical abstracts over the years to the urea
method .

The urea and hypochlorite method was published 1921 in German , and patents issued in Britain and the US , France and Germany soon after . Attached is a US patent from 1931 .

In 75 years since then , it seems to be glaring omission that
the "newer" content wouldn't have appeared in the texts and lab manuals which were still describing the older method
even after the newer method was available . Maybe it was just a lapse in keeping current on what is state of the art ,
which somehow escaped correction in newer publications ,
so the older process became enshrined as standard when it
ought not to have remained standard but updated long ago .

It still seems strange that a material like hydrazine would enjoy that sort of obscurity for so long .....but I have some
"period texts" from that era which fail to place emphasis on the updated method m so there is a sort of institutionalized
ignorance in play , whether it was deliberate , or not .

Attachment: US1959503 Hydrazine via Urea and Hypochlorite , Merck , circa 1931.pdf (108kB)
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[*] posted on 26-7-2007 at 09:42


Then Polverone's explanation comes into play. Academic and industrial labs judt buy he stuff. Here hydrazine hydrate gets sold in 25 L pails.
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[*] posted on 26-7-2007 at 09:46


I think academic sloppiness gets the prize .

They just dropped the ball on this one .

[Edited on 26-7-2007 by Rosco Bodine]
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[*] posted on 26-7-2007 at 20:20
and the band played on


:D Alright men , so who is planning to re-instate the Titan II missile ?
Sure , for industrial scale there are more streamlined methods.
I believe that most if not all are mentioned in those references I listed.
http://www.sciencemadness.org/talk/viewthread.php?tid=1128&a...
For the do it yourself amateur 1/2 a liter of stuff is surely sufficient and
a working recipe is invaluable. Granted that Brauer is dated , but Raschig
is , if somewhat abreviated , the method of preparation it outlines.
90 % of the items online refer to Raschig also , the remainder invoke the
Hoffman urea approach. You need to search graduate chemistry texts to
even see any mention of others. Thats been my experience.

To a casual viewer this nine page long thread of tweaks is reminiscent of
that " phorone " debacle with hardly anything identifiable as a process ,
something is dignified as such only when it is reproducible by others and
verifiably peer reviewed. If the newer means developed here are so much
better , in terms of yield perhaps , how could anyone tell , and how would
they know it ? I offer the example of the preceding half page of banter and
water cooler small talk ( isn't there a whimsy section for that ) Not a wit of
on topic information and a single citation hardly more than an abstract
exhumed from the attic of the Patent and Trademark Office , not exactly a
peer reviewed validation. Not surprising my opening remark was interpreted
as a dismisal by the " Hydrazine conspiracy " of whatever meaningful work
preceded in this thread .

Grumbled expletives are not informative , nor can I fathom such umbrage.
I'm reminded of the scene from the motion picture " Dr. Strangelove "
when the president ( Peter Sellers ) is on the red phone to the premier of
U.S.S.R., and exclaims " keep your feet on the ground when you're talking
Demitre , keep your feet on the ground Demitre , of course this is a friendly
call Demitre , ". In between invective tirades , Roscoe Bodine communicates
to me the following _
" I *already* have given references , along with details and experimental
results based on a small scale adaptation of the Merck patent process
involving sodium hypochlorite and urea. " ( in other words , can you spot
Waldo ? or is it Mr. Anonymous ) Amazingly this still hasn't been cited.
It would have better served everyone to just point this out in the first place
with a reprove that I am out of date and uninformed. As it is , anyone just
tuning in is left wondering what in the world is this soap opera all about.
Does this sound at all familiar to anyone ?

N E W - B E S T . H Y D R A Z I N E . P R E P A R A T I O N . ( so I am told )

http://sciencemadness.org/talk/viewthread.php?tid=757#pid653...
http://sciencemadness.org/talk/viewthread.php?tid=757#pid656...

______________________________________________________

P.S.
If anyone is interested I'll post my patent ( pending ) method
for hydrazine by electrolysis of sodium amide in liquid ammonia :D

.
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[*] posted on 26-7-2007 at 22:18


It's such an irony isn't it , when the state of the art is
right in front of you while you are looking everywhere else for it ! We are talking about an 86 year old technology as compared with a 101 year old technology .
If you are just wanting to be primitive , stick with the genuine antique ....crank the engine using the hand crank instead of trusting in the newfangled electric starter:D

Try this . If you need a few hundred grams of hydrazine sulfate for experimentation , and you are going to synthesize it instead of ordering it from a supply house ,
then your easiest route will be the improved hydrazine synthesis , by waldo , mr. anonymous , or rosco :D

Take it to the peer review court of your choice and
dispute the validity of my detailed description of a valid *lab scale* synthesis for which a dozen personally done experimental confirmations is sufficient for me . And a few others here have confirmed the synthesis . It's just tough to beat what's best ...like it's hard to be humble when you know you are great :D

There is nothing about this thread that compares with the phorone peroxide fraud thread , except for people who jump in to solve problems they seem to be the last to know are already solved .....for not having read the thread .

I completely stand by what I have already said .
If you have a problem with Merck and their reputation ,
then go to Darmstadt and take it up with them ,
because when you have successfully impeached their
75 year old patented synthetic process for hydrazine ,
then you will have discredited mine as well . Until then ,
what I have reported and the "tweaks" as you call them
are still state of the art for a lab method , and in effect were already "peer reviewed" 86 years ago ( by the peers who matter anyway :P ) What I can't fathom is why you can't seem to understand that , or why it would seem surprising to you that it would be pointed out / published here . It wasn't just a piece of chemistry trivia dredged up for no particular reason . The forum owner expressed an interest in the information and so I elaborated on it .

The hydrazine sulfate is a precursor of particular interest in connection with azides and tetrazoles , therefore an
efficient synthesis for it is useful , essential actually , for anyone having an interest in total synthesis of such materials .
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[*] posted on 26-7-2007 at 23:47


Quote:
[quote[
Over the years and decades that followed the emphasis of Org.Syn.'s editorial policy shifted. American researchers were no longer forced to prepare their own reagents...


Quite true. In O.S. and I.S., and a number of practical or laboratory technique books as well, you can see this happening of several decades. Newer versions of a book would often have notes at the start of a preparation stating that "compound XYZ is now commercial available ", and that preparation would be absent from the next edition.
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[*] posted on 27-7-2007 at 00:16


I have never seen a prep deleted from Org.Syn. Almost every compound described in Org.Syn. since 1921 is and has been for 50-60-70 years or more, commercially available. Org.Syn. is organized in annual volumes and every decade, Collective Volumes. I have seen safety warning appended to previously published preps, I have seen newer preps of previously covered compounds, but I do not recall ANY compound, once its prep has been published in Org.Syn., every having been cut from subsequent editions (reprints) of the Collective Volumes (annual volumes do noit get reprinted.)

For example, t-butyl azidoformate was described in at least two seperate preparations, at a time when it seemed to be the N-Boc reagent of choice for peptide chemistry. Subsequently it went out of fashion because it was explosive, and because better N-Boc reagents appeared such as Boc-ON. However the preparations of t-Bu azidoformate are still presented in the online Wiley free edition of CV 1 through 10 and I am sure they are also in the hard copy.

I don't question that in some text, somewhere, what you are saying may be happening. But I challenge you to show me an example from Org.Syn.

Org.Syn. was never intended to be a manual for kitchen chemistry any more than Vogel was/is. The rationale of its inception and the evolution of its editorial policies over time have been described in various introductory sections and biographies or memorials to late editors. It was intended to assist working professional chemists in industry and academia. You won't find a word in there about garage chemistry, and in fact since they have been touting ACS "Prudent Practices" in every preparation for a long time now, they would seem to have slammed the door on amateurs formally.

None of that prevents these books from being useful to amateurs. It is just unrealistic to expect them to be comprehensive, or to update every prep they visited since 1921. It might be more apropos to criticize someone like Vogel who cribbed so much straight from Org.Syn., for omitting a better procedure that came up in the decade after one was published in Org.Syn., but was still in time for his bppk. However IIRC Vogel did not describe the prepration of hydrazine at all.
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[*] posted on 27-7-2007 at 03:15


But was the use of urea ever published as an experimental in an article? The literature sources mentioned above take their cue from previously published work, and patents don't count. Not a whole lot of journal (other than IEC, for instance) or lab manual authors read, cite, or experiment from patent literature, so it is hardly a surprise. The only article where urea is used that I know of is in Safybi, which pretty much defines obscure. It is not completely absent from the available lab manuals, it appears in Vorobyova, which is of course translated from Russian.



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[*] posted on 28-7-2007 at 07:28


Similar omission scenarios exist where gaps in the literature , for whatever reason lead to what I call
"lost art" . This leaves many contemporary chemists
unknowledgeable about even the existence of the prior art since it can't easily be found by a search ...may never have even been indexed . The body of literature is so vast that this is not a rare occurence even for well known compounds . Patents are something I spend a fair amount of time reading because the data is easily searchable and extensive , generally reliable , and often references related material , and by law requires a search of related art by the examiners who then add their own
notes to the applicants . I see a few people making disparaging remarks about patents reliability , and yet a journal article can't be defended in court as a legal claim ,
while a patent most definitely can ....so which has the greater validity legally and technically ? The academic basis certainly has reason to be there for a paid publication which costs the submitter several thousand dollars to register as a legal document ....claiming the disclosed technology as being their intellectual property ,
that is their *invention* and more than any published reasearch finding .....although it is usually that also .
Often there are patents directly associated with the author of a journal article parallel to the patent and a search for author as inventor will turn up hits . But often it is also the case that the patent alone exists as the means of publication , and chemical abstracts lists these
patents ....even if there is no associated journal article ,
the patent speaks for itself dressed in the lawyers suit , even without a crew of labcoats affirming its validity :D
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[*] posted on 15-8-2007 at 05:26


Hm?
OK have a look at this.
http://www.freepatentsonline.com/4455816.html

Now your question was "a journal article can't be defended in court as a legal claim ,
while a patent most definitely can ....so which has the greater validity legally and technically ?"
Well, there are 2 answers as I see it. Legally the patent wins; technically... you just wouldn't see that in a technical paper.
There is no requirement for a patent to work. Methods wriitn up in peer revoied journals do usually work- those that don't get lost in history.
There are often good reasons why, even for perfectly good ideas, some vital details are left out of patent descriptions. Most notably it makes it more difficult for someone to pirate the idea.
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