Editing Purine (section)

==Laboratory synthesis==
In addition to ''[[in vivo]]'' synthesis of purines in [[purine metabolism]], purine can also be synthesized artificially.

Purine is obtained in good yield when [[formamide]] is heated in an open vessel at 170&nbsp;°C for 28 hours.<ref name="Yamada">{{cite journal|journal=Chemical & Pharmaceutical Bulletin|year=1972|volume=20|page=623|title=A One-step Synthesis of Purine Ring from Formamide| vauthors = Yamada H, Okamoto T |doi=10.1248/cpb.20.623|issue=3| url=https://www.jstage.jst.go.jp/article/cpb1958/20/3/20_3_623/_article| archive-url=http://arquivo.pt/wayback/20160516170519/http://www.journalarchive.jst.go.jp/english/jnlabstract_en.php?cdjournal=cpb1958&cdvol=20&noissue=3&startpage=623| url-status=live| archive-date=2016-05-16|doi-access=free}}</ref>

:[[Image:Purinesynthesis-en (cropped).svg|250px]]

This reaction and others like it have been discussed in the context of [[abiogenesis|the origin of life]].<ref name="Saladino">{{cite journal | vauthors = Saladino R, Crestini C, Ciciriello F, Costanzo G, Di Mauro E | title = About a formamide-based origin of informational polymers: syntheses of nucleobases and favourable thermodynamic niches for early polymers | journal = Origins of Life and Evolution of the Biosphere | volume = 36 | issue = 5–6 | pages = 523–531 | date = December 2006 | pmid = 17136429 | doi = 10.1007/s11084-006-9053-2 | s2cid = 36278915 | bibcode = 2006OLEB...36..523S }}</ref>

Oro and Kamat (1961) and Orgel co-workers (1966, 1967) have shown that four molecules of [[Hydrogen cyanide|HCN]] tetramerize to form [[diaminomaleonitrile|diaminomaleodinitrile]] ('''12'''), which can be converted into almost all naturally occurring purines.<ref>{{cite journal | vauthors = Sanchez RA, Ferris JP, Orgel LE | title = Studies in prebiotic synthesis. II. Synthesis of purine precursors and amino acids from aqueous hydrogen cyanide | journal = Journal of Molecular Biology | volume = 30 | issue = 2 | pages = 223–253 | date = December 1967 | pmid = 4297187 | doi = 10.1016/S0022-2836(67)80037-8 }}</ref><ref>{{cite journal| vauthors = Ferris JP, Orgel LE |title=An Unusual Photochemical Rearrangement in the Synthesis of Adenine from Hydrogen Cyanide|journal=Journal of the American Chemical Society|date=March 1966|volume=88|issue=5|page=1074|doi=10.1021/ja00957a050}}</ref><ref>{{cite journal | vauthors = Ferris JP, Kuder JE, Catalano AW | title = Photochemical reactions and the chemical evolution of purines and nicotinamide derivatives | journal = Science | volume = 166 | issue = 3906 | pages = 765–6 | date = November 1969 | pmid = 4241847 | doi = 10.1126/science.166.3906.765 | bibcode = 1969Sci...166..765F | s2cid = 695243 }}</ref><ref>{{cite journal | vauthors = Oro J, Kamat SS | title = Amino-acid synthesis from hydrogen cyanide under possible primitive earth conditions | journal = Nature | volume = 190 | issue = 4774 | pages = 442–3 | date = April 1961 | pmid = 13731262 | doi = 10.1038/190442a0 | bibcode = 1961Natur.190..442O | s2cid = 4219284 }}</ref><ref>{{cite book | vauthors = Bauer W |title=Houben-Weyl Methods of Organic Chemistry |volume=E 5 |edition=4th Supplement |date=1985 |publisher=Thieme Georg Verlag |isbn=978-3-13-181154-7 |page=1547}}</ref> For example, five molecules of HCN condense in an exothermic reaction to make [[adenine]], especially in the presence of ammonia.
:[[Image:Basicpurines.png]]

{{anchor|Traube purine synthesis}}
The '''Traube purine synthesis''' (1900) is a classic reaction (named after [[Wilhelm Traube]]) between an [[amine]]-substituted [[pyrimidine]] and [[formic acid]].<ref>{{cite book |title=Organic Syntheses Based on Name Reactions | vauthors = Hassner A, Stumer C |publisher=Elsevier |year=2002 |edition=2nd |isbn=0-08-043259-X}}</ref>
:[[Image:TraubePurineSynthesis.svg|Traube purine synthesis]]