Toluene → 3,3-Dimethyl-12-isopropyl-1-aza-1,5,9-cyclododecatriene

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Under a blanketing gas (argon), 2.57 g (0.01 mol) of nickel acetylacetonate and 1.66 g (0.01 mol) of triethyl phosphite are dissolved in 120 g of absolute toluene, after which the solution is saturated at 20°-25° C. with 1,3-butadiene. 3.9 g (0.03 mol) of ethoxydiethylaluminium are then slowly added dropwise, whilst passing in a gentle stream of 1,3-butadiene, and during the addition the original green colour changes in the course of 5 minutes to light red. The reaction mixture is heated to 60° C. and 122.5 g (0.98 mol) of N-isobutylidene-2-methylpropenylamine [prepared by reacting isobutyraldehyde with ammonia in accordance with J. Org. Chem., 26, 1822-25 (1961); boiling point 139°-141° C./760 mm Hg] are added dropwise in the course of 45 minutes, whilst passing in a vigorous stream of 1,3-butadiene, at such a rate that the butadiene passed in is just consumed. After the dropwise addition has ended, the mixture is stirred for a further 1 hour at 60° C. whilst continuously passing in 1,3-butadiene, and is then cooled to 20°-25° C. In order to deactivate the catalyst, 0.32 g (0.01 mol) of sulphur is added to the reaction solution and the solution is distilled. A first fraction, which in addition to 120 g of toluene also contains traces of triethyl phosphite and butadiene dimers (gas chromatogram), is obtained at a bath temperature of up to 50° C./1 mm Hg. Subsequent fine distillation yields 212.5 g (0.912 mol) of 3,3-dimethyl-12-isopropyl-1-aza-1,5,9-cyclododecatriene; yield 93% of theory, based on converted N-isobutylidene-2-methylpropenylamine (conversion 100%); boiling point 54°-55° C./0.01 mm Hg; nD20 =1.4832.

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