Preparation of sulfonamides_industrial additives

Background and Overview

Sulfonylsulfonamide can be used as a pharmaceutical synthesis intermediate and an organic synthesis intermediate. It can be used in the laboratory research and development process of sodium bicarbonate and the chemical and pharmaceutical synthesis process. For example, it can be used to prepare sulfonylsulfuron-methyl. Sulfosulfuron-methyl is a newly developed sulfonylurea super-efficient herbicide in recent years. Its chemical name is 1-(4,6-dimethoxypyrimidin-2-yl)-3-(2-ethylsulfonate). Acyl imidazo[1,2-a]pyridin-3-yl)sulfonylurea.

Preparation of sulfonamides

The preparation of sulfonamides is as follows:

25.7g of the reactant 2-ethylthioimidazole[1,2-a]pyridine-3-sulfonamide (0.1mol), 0.1g of sodium tungstate as the catalyst and 250ml of acetic acid as the solvent were placed in the reaction In the bottle, the temperature was raised to 70°C, and 27.2g of hydrogen peroxide (0.24 mol) with a concentration of 30 wt% as an oxidizing agent was slowly added dropwise into the reaction bottle for oxidation reaction. After the dropwise addition, the reaction was continued for 5 hours. The reacted system was then cooled to 15°C. Suction filtration, the obtained filter cake was washed with 120 ml of water and dried at 80°C for 12 hours to obtain 26.0 g of the product 2-ethylsulfonylimidazole [1,2-a]pyridine-3-sulfonamide (sulfonamide ) is an off-white solid with a purity of 98%, a melting point of 198.5~201.6°C, and a yield of 88%.

Preparation and application of sulfonamides

Sulfonylsulfonamide can be used as a pharmaceutical synthesis intermediate, such as the preparation of sulfonylsulfuron-methyl.

14.45g of sulfonamide (0.05mol), 13.8g of 2-amino-4,6-dimethoxypyrimidinecarboxylic acid phenyl ester (0.05mol) as the reactant, and 2.8g of hydrogenation as the catalyst Potassium (0.05 mol) and 100 ml of acetonitrile as solvent were placed in a reaction bottle, heated to 60°C and kept for 7 hours. Then the reaction product was poured into ice water, and 8 ml of hydrochloric acid was used to make the reaction product acidic. Filter, wash the filter cake obtained by filtration with 60 ml of water, then wash with a small amount of methanol, and dry at 80°C for 12 hours to obtain 22.3g of sulfosulfuron-methyl white solid with a purity of 95% and a melting point of 202.5~204.1°C. , the yield reaches 90%.