tert-Butanol → [5-(Tetrahydropyran-2-yloxy)benzofur-7-yl]acetonitrile

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Reaction Steps

Combine 5-(tetrahydropyran-2-yloxy)benzofuran-7-carboxaldehyde (3.75 g, 0.015 mol) with lithium cyanide-tetrahydrofuran (1:1.5 complex, 0.215 g, 0.1 equivalent) in tetrahydrofuran (80 mL) under nitrogen. Add diethyl cyanophosphonate (3.0 ml, 1.3 equivalents) and stir at 20° C. for 2 days. Add tert-butanol (1.6 mL, 1.1 equivalents) then SmI2 in tetrahydrofuran (0.1 M solution, approximately 400 mL). Concentrate the solution in vacuo then redissolve in a solution of ethyl acetate:diethyl ether (approximately 3:1, 100 mL). Add saturated aqueous ammonium chloride and stir for 20 min, until the release of hydrogen cyanide is complete. Filter to remove insoluble material, then extract against 1 N hydrochloric acid. Dry over sodium sulfate, then filter and concentrate. Purification by a plug column (4:1 hexanes:ethyl acetate) to provide the title compound as a light yellow oil.

Provenance & Evidence