Patent ID: 6329535
Filing Date: 2001-12-11
Classification: C07C,C07D,Y02P

Abstract:
A process for preparing esterified chroman compounds, comprising1.1 reacting ketoisophorone (KIP), present with technical grade purity, with an acylating agent in the presence of a proton acid to give a solution of trimethylhydroquinone ester (TMHQ ester) and1.2 reacting said ester with an allyl alcohol derivative or an allyl alcohol in the presence of zinc halides and proton-producing acids, and1.2 steps 1.1 optionally taking place in the presence of an organic solvent,1.1.1 cooling the solution obtained in reaction step 1.1 to a temperature between 5 and40.degree. C., to crystallize out a product,1.1.2 separating the product which crystallizes out and washing said product,1.1.3 obtaining a filtrate by separation and optionally washing and using it as the solvent for the next mixture in accordance with reaction step 1.1,1.2.1 using the optionally washed product in the reaction in accordance with 1.2 without being dried and1.2.2 isolating the desired product, optionally after further acylation.