REMARKABLE SELECTIVITY IN THE REACTION OF 1-TRITYL-I-LITHIOIMIDAZOLESWITH T-BUTYL HALOGENOACETATES

2-Lithio-1-triphenylinethylimidazoles react with t-butyl halogenoaceta tes to give a variety of products, the nature of which is cleanly dete rmined by the halogen atom. With chloroacetate the products are chloro methyl ketones, while bromacetate gives di-t-butyl imidazolesuccinates , and iodoacetate yields iodoimidazoles. In each case 50% of the paren t triphenylmethylimidazole is recovered from the reaction. When the tr iphenylmethyl substituent is replaced by the N,N-dimethylsulfamoyl gro up, reaction with bromoacetate is suppressed, but t-butyl chloroacetat e and iodoacetate again give chloroketones and aryl iodides respective ly.