| 摘要 |
PURPOSE:To obtain 1-methylcyclopentadiene and/or 2-methylcyclopentadiene in high yield by isomerization of 5-methylcyclopentadiene as a unused component using an aromatic sulfonic acid as a catalyst. CONSTITUTION:5-Methylcyclopentadiene as a unused component is isomerized in the presence of an aromatic sulfonic acid (e.g. benzenesulfonic acid, p- toluenesulfonic acid, p-xylene-2-sulfonic acid), thus obtaining 1- methylcyclopentadiene and/or 2-methylcyclopehtadiene in high yield at a low cost. With the present method, the isomerization can be performed at relatively low temperatures. No loss of the products due to their thermal dimerization or thermal polymerization will lead to their high yield. The present products are useful as curing agents for epoxy resins or starting materials for e.g. unsaturated polyester resins. |
