xxxxx - 27-11-2005 at 13:19
(1) starting from para dichlorobenzene, bromine is added. bromine is deactivating, so the reaction should stop at monobromination. (2) the product is
heated with anhydrous aluminum chloride at 140C for 8 to 12 hours to cause intramolecular disproportionation to form the more thermodynamically stable
3,5 dichloro bromobenzene. there will be some intramolecular disproportionation with this step. (3) a grignard reaction is performed in ethyl ether to
replace the bromine with the desired alkyl group (4) the chlorines are converted to hydroxyl by heating with NaOH with copper catalyst at 140C to
reduce the benzyne rearrangement reaction in favor of direct replacement to preserve the meta orientation of the substituent groups. (5) catacholic
derivitives are precipitated with lead acetate. hydroquinone derivitives are preciptiated with hydrogen sulfide. polyalkyl derivitives are removed by
vacuum distillation.
i have only read about these separate steps. could anyone speculate whether these steps might represent a viable route to olivetol?