Synthesis of a novel ring‐expanded (“fat”) nucleotide analogue of phosphonomethoxyethylguanine (PMEG) containing the imidazo[4,5‐e][1,3]diazepine ring system

Abstract

The synthesis of 6‐amino‐4,5‐dihydro‐8H‐1‐(2‐phosphonylmethoxyethyl)imidazo[4,5‐e][1,3]diazepine‐4,8‐dione (7), a novel ring‐expanded (“fat”) acyclic nucleotide analogue of phosphonomethoxyethylguanine (PMEG), has been reported. It was prepared in 4 steps in 51% overall yield starting from dimethyl imida‐zole‐4,5‐dicarboxylate.