Preparation of Dimethylaminobutatriene via the Metallic Intermediate

Treatment of the enyne amine H2C=CH—C=CNMe2 with a catalytic amount of r-BuOK in DMSO or HMPT results in the formation of HC=C—CH=CHNMe2 [116]. The first steps in this isomerization are the vinylic deprotonation at C-3 and subsequent protonation of the trancient anion to give the cumulenic amine H2C—C=C=CHNMe2. It is, however, impossible to achieve any accumulation of this amine, since it is thermodynamically less stable than the ynene amine HC CCH=CHNMe2, and the rate of its conversion into the ynene amine is higher than the rate of its formation from the starting compound. If this is treated 

The paraffin oil serves as a heat conductor during the removal of the solvents and the subsequent distillation of the product. 

No solvent is used traces of water and acid in CCI4 cause isomerization to HC=CCH=CHNMe2. The NMR tube must be perfectly dry. 

The yellow colour of the cumulenic amine does not permit an accurate determination of the nD. 

General note The cumulenic amine is extremely sensitive towards oxygen. Traces of oxygen cause a rapid increase of the viscosity and a darkening of the colour. If treated carefully, the compound remains unchanged during storage at —20 °C for a limited period. 

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