Research on the preparation method of 3-chlorobenzonitrile_Kain Industrial Additive

Background and overview^[1]

3-Chlorobenzonitrile is a nitrile compound and an important chemical raw material. It is widely used in the manufacture of drugs, synthetic fibers and plastics. It is also used in industries such as electroplating, steel quenching and mineral processing. Nitrile is also an important synthetic intermediate. It can be converted into carboxyl, ketone carbonyl, amide and other functional groups through different reaction conditions. It can also form active intermediates through aryl periodic iodide or use the activity of triple bonds to further Cyclization generates heterocyclic compounds, etc. Therefore, the synthesis of cyanide has always been valued by many researchers. There are many methods for preparing nitriles. Traditional synthesis methods include Rosenmund reaction (reaction of halogenated aromatic hydrocarbons and CuCN), Sandmann reaction and amine oxidation reaction. New synthesis methods include coupling reactions of aryl halogenated hydrocarbons, arylboronic acids, etc. with cyanating reagents under transition metal catalysis, dehydration reactions of aldoximes or amides, and condensation reactions of carboxylic acids and amines. Although nitriles can be synthesized by various methods as mentioned above, these methods have more or less defects, such as toxic cyanide, expensive and toxic precious metal catalysts, large amounts of dehydration reagents, harsh reaction conditions, long reaction times, etc. .

Preparation^[1]

Preparation of 3-chlorobenzonitrile from 3-chloroiodobenzene: Under a nitrogen atmosphere, add copper chloride (20 mol%, 3.4 mg) and magnets into a 10 mL glass pressure-resistant tube that has been baked in advance. N,N-dimethylformamide (0.5 mL), 3-chloroiodobenzene (0.125 mmol, 1.0 equiv., 29.8 mg) and diethoxymethylsilane (3.0 equiv., 50.4 mg) were then added. The pressure-resistant tube was sealed, the air in the tube was removed and filled with carbon dioxide (5.0 equiv., 15 mL) and ammonia (5.0 equiv., 15 mL). After the addition is completed, place the glass pressure-resistant tube in a metal module preheated to 160°C and stir for 10 hours. After the reaction is completed, cool the reaction system to room temperature and slowly release the pressure. Using dodecane as an internal standard, the yield of 3-chlorobenzonitrile was determined to be 86% through the working curve of gas chromatography.