Chlorotrimethylsilane → Ethyl 2,2-difluoro-3-[4-({[4-(2,2,2-trifluoroethoxy)-1,2-benzisoxazol-3-yl]oxy}methyl)piperidin-1-yl]propanoate

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-(piperidin-4-ylmethoxy)-4-(2,2,2-trifluoroethoxy)-1,2-benzisoxazole (0.51 g, 1.5 mmol, EXAMPLE 2, Step 2) and 1H-benztriazole-1-methanol (0.22 g, 1.5 mmol) in ethanol (6 mL) was stirred at 50° C. for 20 min. The mixture was concentrated in vacuo to give a solid. The residual solid was dissolved with tetrahydrofuran (2 mL) and this solution was added to a mixture of zinc powder (0.20 g, 3.0 mmol), trimethylsilylchloride (0.19 mL, 1.5 mmol), and ethyl bromodifluoroacetate (0.46 g, 2.3 mmol) in tetrahydrofuran (6 mL) at room temperature. The mixture was refluxed for 2 h and then cooled to room temperature. The mixture was filtered and the filtrate was diluted with ethyl acetate and sat. aq. sodium hydrogencarbonate (30 mL). The mixture was extracted with ethyl acetate (50 mL×2) and washed with brine. The combined extract was dried over magnesium sulfate and concentrated in vacuo to give an oil. The residual oil was purified by silica gel column chromatography (hexane/ethyl acetate 4:1) to give 0.34 g (49%) of the title compound as a colorless oil.

Provenance & Evidence