| 摘要 |
1,4-Dienes are prepared by reacting acetylene with an olefinic compound of the general formula <FORM:1076442/C4-C5/1> wherein R1, R2, R3, R4 and R5 are hydrogen or alkyl radicals and R1 and R5 together may be a propylene radical at 200 DEG to 500 DEG C. in a reactor the surface of which is in contact with the reagents and consists of glass or silica enamelled steel. Pressures equal to or above atmospheric pressure are used and the mole ratio of olefin to acetylene is preferably 0.1 to 10. Olefins used include propylene, butene-2, isobutylene, 2-methylpentene-1; 2-ethyl hexene-1, hexene-1 and cyclohexene. The reaction preferably takes place in presence of an aliphatic or aromatic hydrocarbon diluent in the gaseous or liquid phase and may be batchwise or continuous. Excess reagents may be recycled to the reaction zone. The examples describe the reaction of acetylene with propylene or isobutylene.ALSO:Substituted 1,4-dienes are prepared by reacting acetylene with an olefinic compound of the general formula <FORM:1076442/C2/1> wherein R1, R2, R3, R4 and R5 are hydrogen or alkyl radicals and not more than one of them can be halogen, hydroxyl or an esterified carbonyl group, e.g. allyl chloride; allyl alcohol and methyl crotonate at 200 DEG to 500 DEG C. in a reactor the surface of which is in contact with the reagents and consists of glass or silica enamelled steel. Pressures equal to or above atmospheric are used and the mole ratio of olefin to acetylene is preferably 0.1 to 10. The reaction may take place in the presence of an aliphatic or aromatic hydrocarbon diluent in the liquid or gaseous phase and may be a batch or continuous process. |
