Ammonium Chloride → 4-Ethinyl-1,5-dimethyl-3-(trifluoromethyl)-1h-pyrazole

HRID 971086Notes

Reaction equation

Cl[CH:2]=[CH:3][C:4]1[C:5]([C:11]([F:14])([F:13])[F:12])=[N:6][N:7]([CH3:10])[C:8]=1[CH3:9].CC(C)([O-])C.[K+].[Cl-].[NH4+]>C1COCC1>[C:3]([C:4]1[C:5]([C:11]([F:13])([F:14])[F:12])=[N:6][N:7]([CH3:10])[C:8]=1[CH3:9])#[CH:2]

Participants

Conditions

Temperature: 0 °C

Procedure

1.27 g (5.67 mmol) of 4-(2-chloroethenyl)-1,5-dimethyl-3-(trifluoromethyl)-1H-pyrazole from Example 1 are dissolved in 40 ml of dry THF and placed under a protective gas atmosphere. After cooling the reaction solution to 0° C., 1.91 (17.0 mmol) of potassium tert-butoxide are introduced and, after the addition is complete, the mixture is stirred at 20° C. for 3 hours. After the end of the reaction, a saturated ammonium chloride solution (25 ml) is added and the mixture is extracted twice with 30 ml each time of methylene chloride. The combined organic phases are dried over magnesium sulphate, the solvent is removed by distillation and 4-ethynyl-1,5-dimethyl-3-(trifluoromethyl)-1H-pyrazole is isolated as a microcrystalline solid in a yield of 79% of theory.

Workup

additionafter the addition
customAfter the end of the reaction
extractionthe mixture is extracted twice with 30 ml each time of methylene chloride
dry with materialThe combined organic phases are dried over magnesium sulphate
customthe solvent is removed by distillation

Sources & evidence

ORD record: ord-39a38832c0b64342b84735591a9537eb
Source dataset: uspto-grants-2007_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07312350B2

Reaction notes

Loading…