tert-Butyl isocyanide is used in a tin-free procedure for alkyl radical reactions in the presence of a free-radical initiator. It is a useful intermediate in multicomponent reactions. It is also used in the synthesis of coumarines, 4H-chromenes, isoxazolines and to trap 2-cyclopropylidene-1,3-diones.
CAUTION: Use a well-ventilated hood and observe all precautions when using hydrogen cyanide.
To a 1-1, stainless steel Hoke pressure cylinder in a well-ventilated hood is added 196 gm (3.5 moles) of isobutene, 95 gm (3.5 moles) of hydrogen cyanide, and 100 gm (0.7 mole) or cuprous bromide. The cylinder is closed, shaken for 15 hr at 70°C, cooled to room temperature, and vented cautiously in the hood, and the viscous residue is poured slowly into aqueous potassium cyanide (260 gm in 100 ml of water) to decompose the cuprous complex, liberating an organic layer. The organic layer is separated, dried, and distilled under reduced pressure to afford 97 gm, b.p. 60-63°C (314 mm Hg), ng 1.3749, IR 2143 s, 1472 m, 1368 m, 1230 m, 1208 m, 855 w c m - 1; yield, 33% based on starting isobutylene; 16% based on CuBr.
