PREPARATION OF 1-DIMETHYLAMINO-3,7-DIMETHYL-2,6-OCTADIENE

摘要

PURPOSE:To obtain the titled compound, a raw material for synthesizing terpene perfume, etc. in high yield and in high selectivity, by adding dimethylamine to a mixture of a specific catalyst and isoprene under constant conditions to give an intermediate, followed by reacting the intermediate with isoprene continuously. CONSTITUTION:Isoprene is reacted with dimethylamine using a dialkylamide of Li as a catalyst, to give the titled compound shown by the formula III. In the reaction, dimethylamine is added little by little to a mixture of the catalyst and isoprene, to give a compound shown by the formula I, an intermediate, which is continuously reacted with isoprene. In the procedure, such a condition is required that a molar ratio of unreacted iroprene to unreacted dimethylamine in the react-ion system is always kept high about 30-10,000 times molar ratio. The titled compound can be obtained in high yield by suppressing the by-product shown by the formula II.