Adamantane prepn. by isomerising tetrahydro-dicyclo-pentadiene - using aluminium chloride catalyst and hydrogen bromide or bromine

摘要

Reaction mixt. of tetrahydrodicyclopentadiene (II), and AlCl3 is admixed with either (a) 0.5-5 wt.% 10-65 wt.% conc. HBr, w.r.t. amt of (II) or with (b) 0.5-5 (1-2) wt.% Br2, at 10-130 (70-90) degrees C. After completing the reaction the hydrocarbon layer is sepd. from the catalyst; cooled to 30 degrees C to -50 degrees C (25 degrees C to -10 degrees C) and adamantane set free is sepd. Degree of conversion can reach 55 wt.% w.r.t. (II). Catalytic complex of AlCl3 is 10 times cheaper than AlBr3 used in prior art. Reaction time can also be reduced, by up to 10x. Catalyst activity is high, allowing work at low temps. at which by-prods. formation is prevented.