Piperidine → 2-Difluoroacetylimino-3(3-trifluoromethylphenyl)-5-methylthiazoline

Participants

Reaction Conditions

Reaction Steps

A solution of piperidine (0.57 g, 6.7 mmol) in N,N-dimethylformamide (10 ml) charged in a reaction flask was reacted with tetrafluoroethylene, which was made to flow into the flask (ca. 0.7 liter/hr), with vigorous stirring at 50° C. for 10 hours. After cooling to an ambient temperature, 2-imino-3-(3-trifluoromethylphenyl)-5-methylthiazoline hydrochloride (1.29 g, 5.0 mmol) was added tothe reaction mixture and allowed to react overnight at room temperature and then at 50° C. for 8 hours. After cooling to an ambient temperature, the reaction solution was poured intoa saturated aqueous sodium hydrogencarbonate solution, and extracted twice with toluene (100 ml×2). The toluene layer was washed twice with 5% hydrochloric acid (50 ml×2) and water (50 ml) and then brine (50 ml), and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue was subjected to silica gel column chromatography, which afforded 2-difluoroacetylimino-3-(3-trifluoromethylphenyl)-5-methylthiazoline (0.83 g, 2.5 mmol, yield 49%).

Provenance & Evidence