Precursor to Cyclopentadiene
Typical Procedure:The reaction apparatus is assembled by attaching a thermometer, Vigreaux distilling column and Liebig condenser to a 500 mL two necked flask. The receiver is cooled by means of refrigerants or freezing mixtures. Dicyclopentadiene (195 g) is placed in the two necked flask and heated to about 160 ℃ with an electric heating mantle or oil bath. Thermal decomposition begins at about 150 ℃ and distillates at 38~46 ℃ can be obtained (addition of iron powder expedites the thermal decomposition rate of cyclopentadiene). Heating is applied slowly, because rapid temperature increases cause dicyclopentadiene to distill prior to undergoing thermal decomposition. In such a case, re-distillation allows narrow boiling-point distillates. Cyclopentadiene dimerzes rapidly at room temperature and should be used immediately.
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Org. Synth., 1963, coll. Vol. 4, 238; Org. Synth., 1962, 42, 50.
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