Hydroesterification of ethylene oxide catalyzed by 1-butyl-3-methylimidazolium cobalt tetracarbonyl ionic liquid

In this paper, functional ionic liquid 1-butyl-3-methylimidazolium cobalt tetracarbonyl [Bmim][Co(CO)(4)] is prepared in a metathesis reaction between [Bmim]Cl and KCo(CO)(4). The structure of [Bmim](+) is illustrated by (1)H NMR, while [Co(CO)(4)](-) is confirmed by IR(nu(CO)) spectrum. Methyl 3-hydroxypropionate(3-HPM), an intermediate to 1,3-propanediol (1,3-PDO), can be prepared in high yield by hydroesterification of ethylene oxide in the presence of a [Bmim][Co(CO)(4)] catalyst. Under a pressure of 3.7 MPa and at a temperature of 75 A degrees C, the yield of 3-HPM can reach 90.8% in 10 h. Even after the catalyst is recycled three times, a yield of more than 80% can be obtained. A possible reaction mechanism has also been proposed.