Parasols prepn from vanillin and methyl alkyl ketone - in presence of catalyst system contg. weak base and weak acid, for increased yields

摘要

Paradols, useful for synthetic ginger aromas, are prepd. by reacting vanillin with a methyl alkyl ketone in the presence of a catalyst comprising a mixt. of (a) a weak base, e.g. a N-contg heterocyclic cpd. esp. quinoline, piperidine, pyridine, or pref. pyrrolidine, or an alkylolamide esp. ethanolamide, and (b) a weak acid, esp. a 1-12C fatty acid, pref. activ acid or an arylcarboxylic acid, in a ratio such that the pH of the mixt. is 6-7. Higher yields are obtd. than by conventional process using KOH in alcohol and formation of tarry by-prods. is suppressed.