N, N-dimethylformamide (DMF) (480 g, 6.57 mol) was added to a mixture of 4-bromo-1-butene (160 g, 1.19 mol) and potassium thiocyanate (114 g, 1.17 mol), and the mixture was stirred at 100 C for 1.5 h. The insoluble material was removed, the mixture was evaporated, and the DMF-containing 3-butene thiocyanate ( 560 g). Sodium iodide (208 g, 1.40 mol) and calcium carbonate (11.2 g, 0.11 mol) were added to 3-butenyl thiocyanate and the mixture was refluxed with stirring for 2 h. The insoluble material was removed and the mixture was distilled. The insoluble material was removed and the remaining mixture was distilled to obtain 3-butenyl isothiocyanate.
