Tetrahydrofuran → N,N-dimethyl-5-methylthio-1H-pyrazole-1-sulfonamide

Temperature

-78 °C

To a mixture of 4.0 g of N,N-dimethyl-1H-pyrazole-1-sulfonamide and 45 ml of tetrahydrofuran was added dropwise 15.7 ml of a 1.6M n-butyl lithium solution in hexane at −78° C., and the mixture was stirred at −78° C. for 10 minutes. After 2.3 ml of dimethyl disulfide was added to the mixture, the mixture was stirred for 4 hours while the reaction temperature was gradually returned to room temperature. Water was poured into the reaction mixture, and the mixture was extracted with methyl t-butyl ether three times. The combined organic layer was washed successively with a 1N aqueous sodium hydroxide solution and an aqueous saturated sodium chloride solution, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting residue was subjected to silica gel column chromatography to obtain 4.87 g of N,N-dimethyl-5-methylthio-1H-pyrazole-1-sulfonamide of the formula:

1. stirringthe mixture was stirred for 4 hours while the reaction temperature
2. customwas gradually returned to room temperature
3. extractionthe mixture was extracted with methyl t-butyl ether three times
4. washThe combined organic layer was washed successively with a 1N aqueous sodium hydroxide solution
5. dry with materialan aqueous saturated sodium chloride solution, dried over magnesium sulfate
6. concentrationconcentrated under reduced pressure

ORD record

ord-a76069b71adf44e3a4b0334cff8611b1

Source dataset

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07867949B2