3,7-Dimethyl-1-octanol → 1-Chloro-3,7-dimethyloctane

温度

-3 °C

275 ml (1.46 mol) of 3,7-dimethyl-1-octanol were placed in a 1 l four-neck round-bottom flask fitted with dropping funnel, low-temperature condenser and magnetic stirrer bar and cooled to −3° C. 0.7 ml of pyridine were then added and 129 ml (1.77 mol, 1.2 eq) of thionyl chloride were added dropwise at such a rate that the temperautre did not exceed 15° C. (75 minutes). The HCl gas formed was trapped in Ca(OH)2/water in a wash bottle. The mixture was then heated to 130° C. over a period of 40 minutes. After two hours at this temperature, the mixture was cooled to 50° C., volatile constituents were distilled off by application of a vacuum of 100 mbar. The residue was then cooled to room temperature, diluted with 200 ml of n-hexane and washed first twice with 50 ml each time of 10% strength of NaOH solution in water, then with 50 ml of water and finally with 50 ml of saturated aqueous NaHCO3 solution. The solution was dried over Na2SO4, the solvent was removed by distillation on a rotary evaporator. The residue was purified by distillation under reduced pressure (13 mbar, 86-87° C.). This gave 178.9 g (1.01 mol, 69%) of 1-chloro-3,7-dimethyloctane as a colorless oil.