1-Ethyl-3-(trifluoroMethyl)pyrazole synthesis

Yield:362640-54-8 67%

Reaction Conditions:

Stage #1: 3-(trifluoromethyl)pyrazolewith potassium tert-butylate in dimethyl sulfoxide; for 0.0833333 h;
Stage #2: ethyl iodide in dimethyl sulfoxide;

Steps:

1-4 Preparation of ionic liquid 1- ethyl- 3- (trifluoromethyl) -1H- pyrazole (compound 8 in figure 1)

To a stirred solution of 10 g (73.5 mmol) 3 -(trifluoromethyl)- 1H- pyrazole (3) in DMSO (150 ml) were added 9.9 g of potassium tert.-butoxide portion wise. After stirring for 5 minutes drop wise addition of 12 ml of iodoethane followed by stirring overnight were conducted. Water was added afterwards and the pH value was adjusted to 3 by using IN HC1. The mixture was diluted with MTBE and extracted two more times with MTBE. The combined organic phase was washed with Na2S203-solution, water and brine yielding 8 g (67 %) of the ionic liquid 8.

References:

WO2013/167586,2013,A1 Location in patent:Page/Page column 9