Editing Pyrazine (section)

== Synthesis ==
Many methods exist for the [[organic synthesis]] of pyrazine and its derivatives. Some of these are among the oldest synthesis reactions still in use. 

In the '''Staedel–Rugheimer pyrazine synthesis''' (1876), [[2-Chloroacetophenone|2-chloroacetophenone]] is reacted with [[ammonia]] to the amino ketone, then condensed and then oxidized to a pyrazine.<ref>{{cite journal | doi = 10.1002/cber.187600901174 | title = Ueber die Einwirkung von Ammoniak auf Chloracetylbenzol | date = 1876 | last1 = Staedel | first1 = W. | last2 = Rügheimer | first2 = L. | journal = Berichte der Deutschen Chemischen Gesellschaft | volume = 9 | pages = 563–564 }}</ref> A variation is the '''Gutknecht pyrazine synthesis''' (1879) also based on this  [[selfcondensation]], but differing in the way the alpha-ketoamine is synthesised.<ref>{{cite journal | doi = 10.1002/cber.187901202284 | title = Ueber Nitrosoäthylmethylketon | journal = Berichte der Deutschen Chemischen Gesellschaft | date = 1879 | volume = 12 | issue = 2 | pages = 2290–2292 }}</ref><ref>''Heterocyclic chemistry'' T.L. Gilchrist {{ISBN|0-582-01421-2}}</ref>

:[[File:Gutknecht Pyrazine Synthesis.svg|500px|Gutknecht pyrazine synthesis]]

The '''Gastaldi synthesis''' (1921) is another variation:<ref>G. Gastaldi, Gazz. Chim. Ital. 51, ('''1921''') 233</ref><ref>''Amines: Synthesis, Properties and Applications'' Stephen A. Lawrence 2004 Cambridge University Press {{ISBN|0-521-78284-8}}</ref>

:[[File:GastaldiSynthesis.svg|400px|Gastaldi synthesis]]