2,5-dichloro-3-(trifluoromethyl)pyridine → Methyl 4-{[3-chloro-5-(trifluoromethyl)-2-pyridyl]oxy}-5,8-dimethyl-1,1-dioxo-1,2,3,4-tetrahydro-1lambda6-thiochromene-6-carboxylate

Participants

Reaction Steps

0.48 g (1.7 mmol) of methyl 5,8-dimethyl-4-hydroxy-1,1-dioxo-1,2,3,4-tetrahydro-1λ6-thiochromene-6-carboxylate and 0.4 g (1.9 mmol) of 2,5-dichloro-3-(trifluoromethyl)pyridine were dissolved in 20 ml of tetrahydrofuran and subsequently admixed with 0.21 g (1.9 mmol) of potassium tert-butoxide. The mixture was stirred for 3 h and subsequently concentrated using a rotary evaporator. The residue was taken up in 100 ml of ethyl acetate, washed with sat. NaCl solution (2×20 ml), dried over MgSO4 and concentrated using a rotary evaporator. The residue was purified by chromatography (silica gel, ethyl acetate: heptane=1:3).

Provenance & Evidence