An efficient method for the one-pot synthesis of 2-oxazolines from ethyl a-cyanocinnamate derivatives with acetamide and N-bromosuccinimide(NBS) in the presence of K3PO4 was developed. The reaction was performed smoothly and cleanly to give 2-oxazolines in good to excellent yields(up to 95%) in acetone at room temperature. Thirteen examples were investigated and the results indicated that a large range of a-cyanocinnamate derivatives could be suitable for this method. Based on the outcomes of experiment, a possible consecutive nucleophilic addition- cyclization pathway was proposed.
CHEN Zhan-guo XIA Wei WEN Hua WANG Dan LI Ya-nan HU Jun-li