Undecyl thiocyanate

Perhaps the most widely used preparation of thiocyanates involves the reaction of an alkyl halide with either potassium thiocyanate or ammonium thiocyanate. The reaction is not confined to simple alkyl halides but has also been used for the preparations with dihalides, chlorohydrins, secondary alkyl halides, and acyl halides (in the preparation of acyl thiocyanates). The preparation of undecyl thiocyanate is a typical example of the procedure. 

To 145.5 gm (1.5 moles) of potassium thiocyanate dispersed in 340 ml of ethanol heated to reflux, 235 gm (1 mole) of undecyl bromide are added gradually. After addition has been completed, refluxing is continued for 2 hr. The reaction mixture is then cooled to room temperature, diluted with water, and the product extracted with diethyl ether. After the ether solution has been dried with calcium chloride, the ether is evaporated off and the residue fractionally distilled under reduced pressure to yield 184 gm (86.5%), bp 160°-16rc (10 mm). 

---