Synthesis of 2-Functionalized 4-(Diethoxyphosphorylmethyl)-5-(l-bromoalkyl)furans and Their Reactions with Amines

摘要

Phosphorylation of esters and nitriles of 4-chloromethyl-5-alkylfuran-2-carboxylic acids with triethyl phosphite yields the corresponding phosphonates.These compounds are brominated with N-bromo-succinimide in carbon tetrachloride at the alpha-position of the alkyl radical.The resulting 2-(l-bromoethyl)-,2-(l-bromopropyl)-,and 2-(l-bromoisobutyl)furans react with secondary amines following the scheme of nucleophilic substitution.The dehydrobromination product was isolated only in the reaction of ethyl 4-(di-ethoxyphosphorylmethyl)-5-(l-bromoisopropyl)furan-2-carboxylate with triethylamine,but its yield was low.The reactions of bromo phosphonates with lithium carbonate in DMF result in their decomposition.