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Please login or sign up for a free trial to access the full content. Variation 1: Metalation

DOI: 10.1055/sos-SD-012-00398

Grimmett, M. R.Science of Synthesis, (200212499.

Lateral lithiation at C2 of compounds like 1,2-dimethyl-1H-imidazole appears to be thermodynamically favored in some instances, but the isolation of products of ring or side-chain lithiation seems to depend on a number of factors such as metalating agent, reaction conditions, and quenching agent.[‌525‌,‌611‌] The best conditions for lithiation of the 2-methyl group are butylithium in the presence of N,N,N,N-tetramethylethylenediamine, or in diethyl ether at 110°C, butyllithium in tetrahydrofuran, or lithium diisopropylamide in diethyl ether.[‌611‌] Scheme 172 shows a few examples of products 371 isolated by quenching imidazol-2-ylmethyllithiums with electrophiles.

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