View source for Primuline

{{Other uses|Primulin (disambiguation)}}
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| ImageFile = Primuline.png
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| ImageFile1 = Primuline-3D-balls.png
| ImageSize1 = 200px
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| Section1 = {{Chembox Identifiers
|   CASNo = 8064-60-6
|   PubChem = 
|   SMILES = NC(C=C3)=CC=C3C2=NC1=CC=C(C4=NC5=C(C(S
(=O)([O-])=O)=C(C)C=C5)S4)C=C1S2
  }}
| Section2 = {{Chembox Properties
|   Formula = C<sub>21</sub>H<sub>15</sub>N<sub>3</sub>O<sub>3</sub>S<sub>3</sub> (free acid)
|   MolarMass = 453.557 g/mol (free acid)
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| Section3 = {{Chembox Hazards
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}}

'''Primuline''' is a [[dye]] containing the [[benzothiazole]] ring system. Primuline itself is also known as '''Direct yellow 7''', '''Carnotine''', or '''C.I. 49010'''.

The primulines are considered derivatives of [[dehydrothiotoluidine]] (aminobenzenyltoluylmercaptan), which is obtained when [[toluidine|para-toluidine]] is heated with [[sulfur]] for eighteen hours at 180-190 °C and then for a further six hours at 200-220 °C<ref>{{cite journal| title=N/A| author=P. Jacobson| journal=[[Chemische Berichte|Ber.]]| date=1889 |volume = 22| pages =333}}<br/>[[L. Gatterrnann]], ibid. p. 1084</ref>
Dehydrothiotoluidine is not itself a dye-stuff, but if the heating is carried out at a higher temperature in the presence of more sulfur, then a base is formed, which gives '''primuline yellow''' upon sulfonation.<ref>{{cite journal| title=N/A| author=A. G. Green| journal=Journ. Soc. Chem. Ind.| year= 1888| volume= 1| pages=194}}</ref>

Primuline yellow is a mixture of sodium salts and probably contains at least three thiazole rings in combination. It is a substantive [[cotton]] dye of rather fugitive shade, but can be [[diazo]]tized on the fibre and then developed with other components, yielding a series of ingrain colors.

Primuline is usually available as a sodium salt. Primuline is [[fluorescent]].

[[Thioflavin T]] is obtained by the [[methylation]] of dehydrothiotoluidine with [[methanol]] in the presence of [[hydrochloric acid]]. [[Thioflavin S]] results from the methylation of dehydrothiotoluidine with [[sulfonic acid]]. This sulfonic acid on [[oxidation]] with bleaching powder or with [[lead peroxide]], in alkaline solution yields '''chloramine yellow''', which dyes [[cotton]] a beautiful yellow.

==References==
<references/>

*{{1911}}

[[Category:Aromatic amines]]
[[Category:Benzothiazoles]]
[[Category:Sulfonic acids]]
[[Category:Thiazole dyes]]
[[Category:2Fix]]