Effective synthesis of menthol derivative monomenthyl succinate catalyzed by nanoscale silicon dioxide immobilized DMAP derivative in mixed solvent system

Abstract

For the preparation of an immobilized DMAP derivative, 4-dimethyl-aminopyridine (DMAP) is covalently bonded to the surface of nanoscale silicon dioxide by N-alkylation. The immobilized DMAP derivative is first introduced as a catalyst to produce monomenthyl succinate in a mixed solvent system consisting of cyclohexane/acetone (3:2, v/v). The activity of this immobilized DMAP derivative reaches $0.148~\mathrm{mol}_{\mathrm{product}}/\mathrm{mol}_{\mathrm{DMAP}} {\cdot }\mathrm{h}$ and the highest yield of monomenthyl succinate reaches 91.78%. The recyclability and stability of the immobilized DMAP derivative are excellent as demonstrated by its use 10 times during the recycling operation without obvious loss of productivity. This is an efficient heterogeneous catalyst, which can prevent catalyst contamination of the product. In addition, immobilization provides a possibility for continuous production by the use of a packed-bed reactor. Excellent results are obtained, which make the nanoscale silicon dioxide immobilized DMAP derivative a more promising candidate for the industrial production of monomenthyl succinate.

Keywords

• Monomenthyl succinate
• Immobilization
• 4-dimethyl-aminopyridine
• Mixed solvent system
• Continuous production