Pyridine → HCID 22980781, compound

To a solution of 1,1,2,2-tetrafluoroethyldimethylamine (3.2 g, 22 mmol) in diethyl ether (10 ml) and dioxane (10 ml) was added dropwise, under a nitrogen atmosphere, at a temperature of from 0 to 5° C., a solution of BF3-etherate (49% BF3, 5.6 ml, 44 mmol). After the addition had ended, the reaction mixture was stirred for 5 min. Subsequently, pyridine (1.7 g, 22 mmol) and a solution of ethyl prop-1-enyl ether (1.7 g, 20 mmol) in dioxane (2 ml) were added dropwise successively to the reaction mixture at a temperature of from 0 to 5° C. After stirring at room temperature for 6 hours, the reaction mixture was added at a temperature of from 0 to 5° C. to a mixture of sodium hydroxide (4.4 g, 110 mmol) and methylhydrazine (1.4 g, 30 mmol) in water (75 ml) and then stirred at room temperature for 3 h. Subsequently, water (50 ml) was added and the mixture was extracted with methyl tert-butyl ether. The resulting organic phases were dried over sodium sulfate, filtered and freed from the solvent under reduced pressure. 3-Difluoromethyl-1,4-dimethylpyrazole was obtained in a yield of 25%.

1. additionAfter the addition
2. stirringAfter stirring at room temperature for 6 hours
3. stirringstirred at room temperature for 3 h
4. extractionthe mixture was extracted with methyl tert-butyl ether
5. dry with materialThe resulting organic phases were dried over sodium sulfate
6. filtrationfiltered

ORD record

ord-de33352ac25c40a487ecf05ff98a3c98

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08188295B2