How to prepare cuprous thiophene-2-carboxylate_Industrial additives

How to prepare cuprous thiophene-2-carboxylateBackground and overview[1][2]

Cupperrous thiophene-2-carboxylate is an organic copper catalyst that can cause certain damage to the eyes, respiratory system and skin. It can be prepared in one step from thiophene-2-carboxylic acid.

How to prepare cuprous thiophene-2-carboxylatePreparation[2]

Put thiophene-2-carboxylic acid (60g, 0.47mmol), Cu2O (16.7g, 0.12mol) and toluene (180mL) into a 250ml round-bottomed flask. The flask was then equipped with a Dean-Stark trap and a condenser, and the mixture was azeotroped to remove water and refluxed overnight. The brown/red suspension was cooled to 60°C and the product was vacuum filtered using a pouring funnel under an argon atmosphere. Wash the filter cake with anhydrous methanol under argon to remove excess acid, then use anhydrous ether until the eluent is colorless, and then wash with a small amount of hexane. The product was dried under a flow of Ar, then transferred to a flask and further dried under vacuum. The product was obtained as a dark brown/red, air-stable powder in 80% yield. CuTC is somewhat sensitive to air when in contact with solvents. Once the product is dry, it can be stored and handled at room temperature without any special precautions.

How to prepare cuprous thiophene-2-carboxylateApplications[1][3]

CN201310186221.8 discloses a method for preparing 8-aryl bromopyridine or alkenyl-substituted xanthine compounds, including: under the action of a copper salt catalyst, xanthine The compound reacts with the disulfide compound to generate 8-thiaxanthine compound; under the action of tris(dibenzylideneacetone)dipalladium and thiophene-2-carboxylic acid copper, the 8-thiaxanthine compound generates 8-aryl or Alkenyl-substituted xanthine compounds. For the first time, the present invention uses cheap copper salts as catalysts to successfully prepare 8-thioxanthine compounds in one step, and then synthesizes the target product simply and effectively. The preparation is simple, the yield is high, and it has good application prospects.
CN201510714421 discloses a method using benzonitrile as a starting material, reacting with o-dibromobenzene under the action of a palladium catalyst, organic copper and organic phosphine ligands to obtain 2- Bromo-2′-carbonitrile biphenyl; 2-bromo-2′-carbonitrile biphenyl undergoes hydrolysis and ring-closing reaction to produce the target product 4-bromofluorenone. Fluorene derivatives are a class of luminescent materials with promising applications. The palladium catalyst is palladium acetate, tetrakis(triphenylphosphine)palladium or bis(dibenzylideneacetone)palladium, and the dosage is 2%-5% of the molar amount of o-dibromobenzene. The copper catalyst is copper thiophene-2-carboxylate (CuTC), and the amount is equimolar to the palladium catalyst lithium metaborate.

Main reference materials

[1]CN201310186221.8 Preparation method of 8-aryl or alkenyl-substituted xanthine compound
[2]FromJournalofOrganicChemistry,72(12),4440-4448;2007
[3]CN201510714421.5 A production method of 4-bromofluorenone