Given the importance of substituted imidazoles in biological and pharmaceutical chemistry, it is understandable that 1-N protecting groups are continually being developed.'-'2 A large variety of these are known (la-g). All allow formation of a C2 or a C5 anion, but each suffers from one or more disadvantage which precludes its general applicability. These may include:(1) incomplete lithiation of C2, sometimes competitive with lithiation of the ...
