| 摘要 |
a ,b -Ethylenically unsaturated carbonylic compounds are prepared by contacting a C3-C6 acyclic mono-olefin having a terminal double bond and at least 2 allylic hydrogen atoms with a mercury salt, an inorganic compound containing pentavalent vanadium and oxygen, and an aqueous solution of a strong acid, hydrolyzing the resulting mixture containing a mercuric salt-olefin complex with water at 80-150 DEG C. to produce the desired product, separating the resulting mercurous salt from an aqueous solution containing reduced vanadium, treating the latter at 120-250 DEG C. with oxygen under pressure to form a pentavalent vanadium product, and recycling this and the mercurous salt to the initial reaction. The mercury may be present initially in the mercurous or mercuric state and vanadium in the tetravalent state. The acid should have a pH below 3 in 0.1N solution at 25 DEG C., and should not be a hydrogen halide or contain an anion complexing with Hg. Sulphuric is preferred and may be used in 0.5-15% by weight aqueous solution. Mercury and vanadium sulphates are then preferred. Temperatures of 0-70 DEG C. and pressures of 1-30 atm., preferably sufficient to liquefy at least part of the olefin, are used. The conversion of propylene to acrolein is exemplified. Isobutylene yields methacrolein, butene-1 methyl vinyl ketone, and hexene-1 principally propyl vinyl ketone. |
