Synthesis of 2-Azabicyclohept-5-en-3-one as an Intermediate for Abacavir

2-Azabicyclohept-5-en-3-one was synthesized from sodium-p-toluene sulfinate with cyanogens chloride and cyclopentadiene by one-pot process.The optimal conditions were as follow: the mole ratio of sodium-p-toluene sulfinate:cyanogens chloride:cyclopentadiene was 0.48∶1.05∶1,the reaction temperature 15℃,reaction time 5 h and pH of the reaction 5.Under these optimal conditions,the purity of product was 95%,and The yield was increased from 64% to 78%.