| 摘要 |
Diaryl hydrocarbons are prepared by condensing an aryl compound with an aliphatic aldehyde or ketone as defined below by bringing the reactants simultaneously at a temperature above 5 DEG C. into contact with an acidic catalyst having a dehydrating effect equivalent to at least that exhibited by sulphuric acid of 85% concentration. The aldehyde or ketone should have a straight or branched chain structure containing the carbonyl group which structure may contain a saturated or unsaturated ring not attached to the carbonyl group or a saturated ring structure attached to the carbonyl group or of which the carbonyl group is a part. The carbonyl compound may have 1-30 carbon atoms and 1-6 carbonyl groups, many being specified. The aryl compound may have one or more rings at least one being an aromatic ring with at least one open position. Rings can be condensed or joined through divalent saturated or unsaturated substituted or unsubstituted C1-C20 aliphatic groups. The catalyst may be sulphuric acid of at least 85% concentration, boron trifluoride, hydrogen fluoride, phosphoric acid or zinc chloride. The weight ratio of aryl to carbonyl compound may be 1 : 100 to 100 : 1, preferably the aryl compound is in excess. The catalyst is preferably present in a mole ratio to carbonyl compound of at least one. Pressure may be 0-14 kg./cm.2 and temperature 15 DEG C-60 DEG C. and the reaction time is generally less than 5 minutes. The reactants may be mixed and added to the catalyst or may be added separately, simultaneously. In the Examples (1) toluene and acetaldehyde with 96% sulphuric acid yield 1,1-di-(p.-tolyl)ethane (3) xylene and acetaldehyde with 96% sulphuric acid yield dixylylethane (4) toluene and heptadehyde with 96% sulphiric acid yield ditolylheptane. |
