Metallation of Benzyl Dimethylamine with BuLi -f-BuOK

6 a-Metallation of Benzyl Dimethylamine with BuLi f-BuOK 

Hauser et al. [1] investigated the metallation of JV.JV-dimethyl benzylamine with a number of strong bases. Whereas BuLi and BuNa gave either exclusively the O-metallated or a-metallated derivative, the reaction with PhLi, PhNa, and PhK led directly to the a-metallated product. A similar result is obtained when treating the amine with BuLi t-BuOK (= BuK ) in a mixture of THF and hexane [2]. The dark-red solution thus obtained reacts very smoothly with alkyl halides even at very low temperatures. In fact, the reaction with methyl iodide may be carried out like a titration using the characteristic colour as indicator. 

---