A number of pilocarpine analogues containing the (S)-3-ethyl-4-[(4'-imidazolyl) methyl]-2- oxazolidinone (9) structural feature were synthesized from L-histidine. With 1-benzyl-L- histidine as the key intermediate, a regiospecific synthetic route was developed to the N"- methyl derivative 8. The regiochemistry of the alkylation of the imidazole nucleus was determined by measuring proton cross-ring coupling constants in the high-field'H NMR. ...
