Sulfuric Acid → Pyrazosulfuron-ethyl

Participants

Reaction Conditions

Reaction Steps

2.603 g of 4-ethoxycarbonyl-1-methylpyrazole-5-sulfonylchloride was dissolved in 20.0 ml of acetonitrile. To the resulting solution were added 0.715 g of sodium cyanate and 1,552 g (10.0 mM) of 4,6-dimethoxy-2-aminopyrimidine with stirring. The reaction mixture was maintained at 40° C. for about 10 minutes and then 0.396 g of pyridine was added dropwise thereto over 5 minutes via a syringe. While maintaining the temperature of 40° to 45° C., the reaction mixture was continuously and vigorously stirred for 3 hours to complete the reaction. After the reaction was completed, the reaction mixture was adjusted to pH 4 by adding 5% aqueous sulfuric acid solution and dichloromethane to extract the reaction product. The extracted organic layer was dried over anhydrous magnesium sulfate and then filtered. The organic solvent was removed from the filtrate to obtain 4.103 g (Yield 99%) of the title compound in the solid state.

Provenance & Evidence