Editing Crystal violet (section)

==Production==
A number of possible routes can be used to prepare crystal violet.<ref name="ci1971">{{Citation |title=Colour Index 3rd Edition Volume 4 |url=https://www.colour-index.org/help/3121_Triarylmethane.pdf |page=4391 |year=1971 |archive-url=https://web.archive.org/web/20110719160728/https://www.colour-index.org/help/3121_Triarylmethane.pdf |place=Bradford |publisher=Society of Dyers and Colourists |archive-date=2011-07-19 |url-status=dead}}</ref><ref name="gessner2002">{{Citation |last1=Gessner |first1=T. |title=Ullmann's Encyclopedia of Industrial Chemistry |edition=6th |year=2002 |contribution=Triarylmethane and Diarylmethane Dyes |place=Weinheim |publisher=Wiley-VCH |doi=10.1002/14356007.a27_179 |last2=Mayer |first2=U.|isbn=978-3-527-30385-4 }}</ref> The original procedure developed by the German chemists Kern and [[Heinrich Caro|Caro]] involved the reaction of [[dimethylaniline]] with [[phosgene]] to give 4,4′-bis(dimethylamino)[[benzophenone]] ([[Michler's ketone]]) as an intermediate.<ref name=reinhardt2000/> This was then reacted with additional dimethylaniline in the presence of [[phosphorus oxychloride]] and [[hydrochloric acid]].<ref name=patents/>

The dye can also be prepared by the [[Condensation reaction|condensation]] of [[formaldehyde]] and [[dimethylaniline]] to give a [[leuco dye]]:<ref name=ci1971/><ref name=gessner2002/><ref name="thetner2000">{{Citation |last=Thetner |first=D. |title=Kirk-Othmer Encyclopedia of Chemical Technology |url=https://mrw.interscience.wiley.com/emrw/9780471238966/kirk/article/tripthet.a01/current/pdf |archive-url=https://archive.today/20130105105555/http://mrw.interscience.wiley.com/emrw/9780471238966/kirk/article/tripthet.a01/current/pdf |url-status=dead |archive-date=January 5, 2013 |year=2000 |contribution=Triphenylmethane and related dyes |publisher=Wiley |doi=10.1002/0471238961 |isbn=978-0-471-48494-3 |url-access=subscription }}. Also available from [https://www.scribd.com/doc/30109454/Triphenylmethane-and-Related-Dyes Scribd] {{Webarchive|url=https://web.archive.org/web/20121104145950/https://www.scribd.com/doc/30109454/Triphenylmethane-and-Related-Dyes |date=2012-11-04 }}.</ref>
:CH<sub>2</sub>O + 3&nbsp;C<sub>6</sub>H<sub>5</sub>N(CH<sub>3</sub>)<sub>2</sub> → CH(C<sub>6</sub>H<sub>4</sub>N(CH<sub>3</sub>)<sub>2</sub>)<sub>3</sub> + H<sub>2</sub>O
Second, this colourless compound is [[Redox|oxidized]] to the coloured [[Ion|cationic]] form (hereafter with [[oxygen]], but a typical [[oxidizing agent]] is [[manganese dioxide]], MnO<sub>2</sub>):
:CH(C<sub>6</sub>H<sub>4</sub>N(CH<sub>3</sub>)<sub>2</sub>)<sub>3</sub> + HCl + {{1/2}}&nbsp;O<sub>2</sub> → [C(C<sub>6</sub>H<sub>4</sub>N(CH<sub>3</sub>)<sub>2</sub>)<sub>3</sub>]Cl + H<sub>2</sub>O