Abstract
S-Melhyl N-(benzotriazol-1-ylmethyl)thioimidate 6 is obtained by lithiation of the corresponding N-(benzotriazol-1-ylmelhyl) thioamide 5 and subsequent reaction with methyl iodide. Derivative 6 undergoes [2 + 3] cycloaddition reactions with
α,β-unsaturated -esters, -ketones and -nitriles, and vinylpyridines which are followed by elimination of benzotriazole and the thioalkoxy group, to give 2,3,4-trisubstituted pyrroles. Lithiaiion of 6 followed by reactions with imines gives cyclized 4,5-dihydroimidazoles
14 which upon further treatment with ZnBr
2 or direct refluxing in toluene yield the 1,25-trisubstituted imidazoles
15 in good yields.