Epoxidation of 1,5,9-cyclododecatriene with H2O2 in the presence of tungstophosphoric acid (H3PW12O40)

The influence of the technological parameters on the epoxidation of 1,5,9-cyclododecatriene (CDT) to 1,2-epoxy-5,9-cyclododecadiene (ECDD) by the phase-transfer catalysis method (PTC) in the presence of tungstophosphoric heteropolyacid (H3PW12O40) and hydrogen peroxide as the oxidizing agent has been presented. The phase-transfer catalyst was Aliquat (R) 336 (methyltrioctylammonium chloride). The epoxidation of CDT to ECDD in the PTC system proceed under the relatively mild condition: low temperature, lack of solvent, short reaction time. The effect of: the mixing velocity, the molar ratio of CDT:H2O2 and H2O2:H3PW12O40, the nature of the solvent and its concentration, was studied. The most advantageous technological parameters were: the mixing rate 400 - 600 rpm, the molar ratio of CDT:H2O2 = 3:1 - 1.5:1, the molar ratio of H2O2:H3PW12O40 = 200:1 - 400:1, the temperature 40 - 50 degrees C, solvent: dichloromethane or lack of the solvent, dichloromethane concentration: 10 - 50 vol%, reaction time 35 - 50 min. The application of the above-mentioned parameters allows to achieve the yield of 44 - 47% ECDD in relation to introduced CDT.