Greener route to 4-vinyl-1-cyclohexane 1,2-epoxide synthesis using batch and continuous reactors

Abstract

Polystyrene 2-(aminomethyl)pyridine (Ps.AMP) supported molybdenum (Mo)(VI) complex (Ps.AMP.Mo) was prepared, characterized and assessed as a catalyst for batch and continuous epoxidation of 4-vinyl-1-cyclohexene (4-VCH) using tert-butyl hydroperoxide (TBHP) as an oxidant. The effect of various parameters such as reaction temperature, feed molar ratio (FMR) of 4-VCH to TBHP and catalyst loading on the conversion of TBHP to 4-vinyl-1-cyclohexane 1,2-epoxide (4-VCH 1,2-epoxide) was studied to optimize reaction conditions in a batch reactor. The long-term stability of Ps.AMP.Mo was evaluated by recycling a sample of the catalyst several times in batch experiments. A detailed evaluation of Mo leaching from the polymer supported catalyst was investigated by isolating any residue from reaction supernatant solutions and then using these residues as potential catalysts in epoxidation reactions. The efficiency of Ps.AMP.Mo catalyst for continuous epoxidation studies was assessed using a FlowSyn continuous flow reactor by studying the effect of reaction temperature, feed flow rate and FMR of 4-VCH to TBHP on the conversion of TBHP and the yield of 4-VCH 1,2-epoxide. The experimental results confirmed very high selectivity and efficiency of Ps.AMP.Mo catalyst for batch and continuous epoxidation.

Keywords

• 4-vinyl-1-cyclohexene
• alkene epoxidation
• continuous flow reactor
• heterogeneous catalysis
• polymer supported mo(vi) catalyst