Preparation of 1-azidooctane
Alternative Names: octane, 1-azido-; n-octyl azide
Alkyl azides are prepared by reacting alkyl bromides or iodides with sodium azide in the aliphatic alcohol solution. Due to the incomplete removal of solvent used for the reaction, considerable difficulty is encountered in isolating the alkyl azide, particularly the formation of azeotropes with both the alkyl halide and the alkyl azide. An improved method of preparing alkyl azides is described based on J. Org. Chem., 1957, 22 (3), pp 238–240, wherein Carbitols are used as solvents for the interaction of an alkyl halide and sodium azide. Moreover, the method eliminates the hazards and restrictions of sealed tubes and the formation of troublesome azeotropes.
To a flask containing 16.9 g (0.26 mole) of sodium azide, 300 ml of butyl Carbitol (2-(2-butoxyethoxy)ethanol), and 60 ml of water is added all at once, with stirring, 48 g (0.20 mole) of 1-iodooctane (or equimolar amount of 1-bromooctane). After a few minutes, the homogeneous solution is heated to 95°C and kept there for 24 hr. After cooling to room temperature, the reaction mixture is poured into 1 liter of ice water. The organic layer is separated and the water layer is extracted with two 200 ml portions of ether. The ether and organic layers are combined, dried, and concentrated. The residue is distilled under reduced pressure (b.p. 62°/3.3 mm) to afford 94.8% of 1-azidooctane (nD=1.4368).
J. Org. Chem., 1957, 22 (3), pp 238–240