Process for the preparation of substituted isoflavone derivative

摘要

PCT No. PCT/HU90/00023 Sec. 371 Date Dec. 5, 1991 Sec. 102(e) Date Dec. 5, 1991 PCT Filed Apr. 6, 1990 PCT Pub. No. WO91/15483 PCT Pub. Date Oct. 17, 1991.The invention relates to a process for the preparation of pure isoflavone derivatives of the general formula (I), <IMAGE> (I) wherein R stands for hydrogen or isopropyl, R2 and R3 stand for hydrogen or C1-2 alkoxy by reacting a rezorcinol-derivative of the general formula (III) <IMAGE> (III) wherein R2 and R3 are as given above with ethyl-orthoformiate of the formula (IV) (C2H5O)3l CH(IV) in the presence of a base and optionally by alkylating the product.