A convenient and highly efficient protocol for one-pot synthesis
of some novel N-heterocycle methyl-O-oxime ethers is described. In this
method, three-component coupling of different types of ketoximes,
with methylene iodide and nitrogen heterocycles, including imidazoles,
benzimidazole, benzotriazole, and theophylline in the presence of
an equimolar mixture of K2CO3/Et3N
in refluxing MeCN furnished the corresponding N-heterocycle
methyl-O-oxime ethers in good yields.
This methodology is highly efficient for the synthesis of various
structurally diverse N-heterocycle methyl-O-oxime ethers. The results of quantum
mechanical studies on reaction intermediates are discussed.
three-component reaction (3CR) - oxime -
O-oxime ether - methylene iodide - N-heterocycle