Sodium Hydroxide → 3,5-Dimethyldodecanoic acid

Temperatur

170 °C

In a nitrogen atmosphere, the crude product (41.6 g, 0.0899 mol) of ethyl 2-(1,3-dimethyldecyl)malonate (4Et) obtained in the method of Example 1-1 and a 13% by weight aqueous sodium hydroxide solution (87 g) were placed in a reaction vessel and stirred for one hour under refluxing with heating. Then ethanol thus generated therein was distilled off in one hour. The resulting mixture was subjected to addition of 20% by weight hydrochloric acid (87 g) and extracted with a mixture of toluene and tetrahydrofuran. The resulting organic phase was concentrated under reduced pressure, and then the residue was stirred under heat at 170° C. for 6 hours in a nitrogen atmosphere. This reaction mixture was diluted with tetrahydrofuran, washed with an aqueous saturated sodium chloride solution, dried over magnesium sulfate, and concentrated under reduced pressure. The concentrate thus obtained was distilled under reduced pressure (bp 130 to 140° C./2 mmHg) to obtain 3,5-dimethyldodecanoic acid (5) (18.9 g, 0.0828 mol). A total yield of three steps from the 2-methylnonyl chloride (1Cl) was 67%.