Editing Hydrazine (section)

==Synthesis and production==
Diverse synthetic pathways for hydrazine production have been developed.<ref name="Ullmann">{{Ullmann|doi=10.1002/14356007.a13_177 |title=Hydrazine |year=2001 |last1=Schirmann |first1=Jean-Pierre |last2=Bourdauducq |first2=Paul |isbn=3-527-30673-0}}</ref> The key step is the creation of the [[Nitrogen|N]]–N single bond. The many routes can be divided into those that use chlorine oxidants (and generate salt) and those that do not.

===Oxidation of ammonia via oxaziridines from peroxide===
Hydrazine can be synthesized from ammonia and hydrogen peroxide with a ketone catalyst, in a procedure called the [[Peroxide process]] (sometimes called Pechiney-Ugine-Kuhlmann process, the Atofina–PCUK cycle, or ketazine process).<ref name="Ullmann"/> The net reaction is:<ref>{{Cite book |url=https://www.elsevier.com/books/chemistry-of-petrochemical-processes/matar-ph-d/978-0-88415-315-3 |title=Chemistry of Petrochemical Processes |last1=Matar |first1=Sami |last2=Hatch |first2=Lewis F. |date=2001 |publisher=Gulf Professional Publishing |isbn=978-1-4933-0346-5 |edition=2nd |location=Burlington |page=148 |oclc=990470096 |via=Elsevier}}</ref>

:{{chem2|2 NH3 + H2O2 → N2H4 + 2 H2O}}

In this route, the ketone and ammonia first condense to give the [[imine]], which is oxidised by hydrogen peroxide to the [[oxaziridine]], a three-membered ring containing carbon, oxygen, and nitrogen. Next, the oxaziridine gives the [[hydrazone]] by [[ammonolysis|treatment with ammonia]], which process creates the nitrogen-nitrogen single bond. This hydrazone condenses with one more equivalent of  ketone. 
:[[File:Pechiney-Ugine-Kuhlmann process.png|506px]]
The resulting [[acetone azine|azine]] is hydrolyzed to give hydrazine and regenerate the ketone, [[methyl ethyl ketone]]:
:{{chem2|[[Methyl group|Me]]([[Ethyl group|Et]])C\dN\sN\dC(Et)Me + 2 H2O → 2 Me(Et)C\dO + N2H4}}

Unlike most other processes, this approach does not produce a salt as a by-product.<ref>{{Cite book |chapter-url=https://www.academia.edu/9511336 |title=Riegel's handbook of industrial chemistry |last1=Riegel |first1=Emil Raymond |last2=Kent |first2=James Albert |date=2003 |publisher=Springer Science & Business Media |isbn=978-0-306-47411-8 |edition=10th |location=New York |page=192 |chapter=Hydrazine |oclc=55023601 }}</ref>

===Chlorine-based oxidations===
The [[Olin Raschig process]], first announced in 1907, produces hydrazine from [[sodium hypochlorite]] (the active ingredient in many [[bleach]]es) and ammonia without the use of a ketone catalyst. This method relies on the reaction of [[monochloramine]] with [[ammonia]] to create the [[Nitrogen|N]]–N [[single bond]] as well as a [[hydrogen chloride]] byproduct:<ref name="OrgSynth">{{cite journal |vauthors=Adams R, Brown BK |year=1922 |title=Hydrazine Sulfate |journal=[[Organic Syntheses|Org. Synth.]] |volume=2 |page=37 |doi=10.15227/orgsyn.002.0037 |s2cid=221547391 }}</ref>
:{{chem2|NH2Cl + NH3 → N2H4 + HCl}}
 
Related to the Raschig process, [[urea]] can be oxidized instead of ammonia. Again sodium hypochlorite serves as the oxidant. The net reaction is shown:<ref>{{cite web |url=http://chemindustry.ru/Hydrazine.php |title=Hydrazine: Chemical product info |website=chemindustry.ru |archive-url=https://web.archive.org/web/20180122212817/http://chemindustry.ru/Hydrazine.php |archive-date=22 January 2018 |access-date=8 Jan 2007}}</ref>
:{{chem2|(NH2)2CO + NaOCl + 2 NaOH → N2H4 + H2O + NaCl + Na2CO3}}

The process generates significant by-products and is mainly practised in Asia.<ref name="Ullmann"/>

The [[Peroxide process#Bayer ketazine process|Bayer Ketazine Process]] is the predecessor to the peroxide process. It employs sodium hypochlorite as oxidant instead of hydrogen peroxide. Like all hypochlorite-based routes, this method produces an equivalent of salt for each equivalent of hydrazine.<ref name="Ullmann"/>