Ethanol → Ethyl 3-chloro-5-(trifluoromethyl)pyridine-2-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

The reaction was carried out in a 100 ml stainless steel autoclave equipped with a magnetic stirring bar. The reagents were charged in a teflon liner in the following order: (1) ethanol (20 ml), (2) sodium acetate (1.70 g, 20 mmol), (3) 2,3-dichloro-5-trifluoromethylpyridine (2.16 g [97 percent], 10 mmol), (4)1,1′-bis(diphenylphosphino)ferrocene (166 mg, 0.30 mmol [3 mol percent]), and (5) palladium acetate (12 mg, 0.05 mmol [0.5 mol percent]). The air in the autoclave was replaced with carbon monoxide and the pressure adjusted to 15 bar. The reaction mixture was then heated to 80° C. (jacket temperature) and the reaction was carried out with stirring. After 5 hours, the reaction mixture was cooled to room temperature, filtered through celite, GC analysis indicated that the mixture consisted of 98 percent of ethyl 5-trifluoromethyl-3-chloropyridine-2-carboxylate. The mixture was concentrated under vacuum and the product was isolated by flash chromatography on silica gel eluting with ethyl acetate/hexane (1:4) affording 2.34 g (92 percent, <99 percent GC area percent). Other data concerning the product was:

Herkunft & Nachweise