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Indigo synthesis

12synthesis methods

Product Name:Indigo
CAS Number:482-89-3
Molecular formula:C16H10N2O2
Molecular Weight:262.26

K. Heumann treated N-phenylglycine with alkali and obtained indoxyl (keto form), which on aerial oxidation converted to indigotin. Later, a variation of the original Heumann process was made: aniline, formaldehyde, and hydrogen cyanide react to form phenylglycinonitrile, which is hydrolyzed to phenylglycine. This is the most widely used process for manufacturing indigotin. The greatest improvement in the manufacture of indigotin came when sodamide was used with alkali in the conversion of phenylglycine to indoxyl. Although there is still demand for indigotin for dyeing blue jeans, it has lost a good part of the market to other blue dyes with better dyeing properties.

91-56-5 Synthesis

91-56-5
454 suppliers
$5.00/25g

482-89-3
378 suppliers
$13.00/100g

Yield:-

Steps:

Multi-step reaction with 2 steps
1: PCl₅ / benzene / 4 h / Heating
2: 70 percent / thiophenol / benzene / 4 h / Heating; further thiophenols used: 1) p-CH₃C₆H₄SH, 2) p-ClC₆H₄SH, 3) m-CH₃C₆H₄SH, 4) o-CH₃C₆H₄SH