Development of potential manufacturing routes for substituted thiophenes – preparation of halogenated 2-thiophenecarboxylic acid derivatives as building blocks for a new family of 2,6-dihaloaryl 1,2,4-triazole insecticides was written by Hull, John W. Jr.;Romer, Duane R.;Podhorez, David E.;Ash, Mezzie L.;Brady, Christine H.. And the article was included in Beilstein Journal of Organic Chemistry in 2007.Recommanded Product: 55406-13-8 This article mentions the following:
Potential manufacturing routes to three halogenated 2-thiophenecarboxylic acid derivatives, namely, 4-bromo-3-methyl-2-thiophenecarbonyl chloride, 3,4,5-trichloro-2-thiophenecarbonyl chloride, and 3,4,5-trichloro-2-thiophenecarbonitrile, from com. available thiophene raw materials have been developed and demonstrated on a laboratory scale. A one-pot bromination/debromination procedure developed for 3-methylthiophene gave 2,4-dibromo-3-methylthiophene. Carboxylic acid functionality was then introduced either by a Grignard metalation followed by carbonation with CO2, or by a palladium catalyzed carbonylation procedure under CO pressure. The vapor phase chlorination of 2-thiophenecarbonitrile with chlorine gas at 500 °C with an average residence time of 6 s gave 3,4,5-trichloro-2-thiophenecarbonitrile in a 69% distilled yield, a process that was carried out on a multi-kilogram scale in the laboratory Finally, a route for the preparation of 3,4,5-trichloro-2-thiophenecarbonyl chloride was developed from tetrachlorothiophene via either a lithiation reaction with n-butyllithium in MTBE, or by a previously reported Grignard method using 1,2-dibromoethane as activator, followed by carbonation of the anion with CO2 to give the trichloro-2-thiophenecarboxylic acid, which was readily converted to the corresponding acid chloride with SOCl2. In the experiment, the researchers used many compounds, for example, 3-Methylthiophene-2-carbonitrile (cas: 55406-13-8Recommanded Product: 55406-13-8).
3-Methylthiophene-2-carbonitrile (cas: 55406-13-8) belongs to nitriles. Nitriles are polar, as indicated by high dipole moments. As liquids, they have high relative permittivities, often in the 30s. In conventional organic reductions, nitrile is reduced by treatment with lithium aluminium hydride to the amine. Reduction to the imine followed by hydrolysis to the aldehyde takes place in the Stephen aldehyde synthesis, which uses stannous chloride in acid.Recommanded Product: 55406-13-8
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts