Patent ID: 7326797

Claim:
A process for manufacturing a hydroxylated isoflavone of the general formula wherein R 1 signifies hydrogen or hydroxy, and R 2 signifies hydroxy or C 1 — 6 -alkoxy, comprising reacting a 2-hydroxydeoxybenzoin of the general formula wherein R 1 and R 2 are defined as above, with a formic acid anhydride of the general formula wherein R 3 signifies C 2-20 -alkyl, C 1-6 -haloalkyl, (C 1-6 -alkoxy)methyl, carboxy-C 2-6 -alkyl, aryl-C- 1-6 -alkyl, a group —CH 2 —(OCH 2 CH 2 ) m —O—C 1 — 6 -alkyl, a group —CH(R 4 )═CR 5 R 6 , a group —CH═CH—COOH, C 3-8 -cycloalkyl, aryl, heteroaryl, di(C 1 — 6 -alkyl)aminomethyl, diarylaminomethyl, a group —(CH 2 ) n —COOR 7 , a group —(CH 2 ) m —COOCHO, a group —CH═CH—COOCHO, C 1-6 -alkoxy, aryloxy or formyloxy, each of R 4 , R 5 and R 6 , independently, signifies hydrogen, C 1-6 -alkyl or aryl, R 7 signifies hydrogen, C 1-6 -alkyl or aryl, m signifies an integer 1 to 4, and n signifies zero or an integer 1 to 8, in the presence of a base or in a solvent which acts as a base, and if necessary promoting the ensuing hydrolysis of the so-produced acylated form of the hydroxylated isoflavone of the formula I by acidification.