yl)pyrimidine are deprotonated with lithium diisopropylamide before being allowed to react with dry ice. In contrast, consecutive treatment of 2-bromo-4-(trifluoromethyl)pyrimidine and 2-chloro-5-iodo-4-(trifluoromethyl)pyrimidine with butyllithium affords the expected carboxylic acids in only poor yields and not even trace amts. of acid were detected when 4-bromo-6-(trifluoromethyl)pyrimidine served