Dimerising vinylidene cpds. - to produce pure, sterically hindered 1-olefin tetramers useful as extreme pressure lubricants

摘要

A process is claimed for the prodn. of a substantially pure dimer of a vinylidene cpd., comprising reacting, at -10 to +200 degrees C a compsn. of the formula: R-(CH2)2-C(R)=CH2 (where each R is independently 4-12C sat. alkyl gp.), in the presence of a catalytic amt. of a 1:1 molar complex of BF3 with a lower alkyl alcohol (1-6C), the compsn. recovered having the formula: R-(CH2)2-C(R)=CH-C(CH3)(R)-(CH2)2-R (where R is as above). In specifically claimed embodiments, R is 6 or 8C sat. alkyl, the process is carried out 0-150 (pref. 30-70) degrees C, and the molar ratio of the BF3-lower alcohol complex to the vinylidenecpd. is 0.01-1 (pref. 0.05-0.2):1. The prods., novel dimers of the vinylidene cpd., specifically tetramers of the 1-olefin, useful as extreme temp. lubricants, such as in aircraft jet engines. The prods. are obtd. routinely and consistently in a quantitative yield and high purity. The double bond is in such position in the molecule that is essentially free from degradation and oxidative attack.