Preparation of quercetin derivatives

Abstract

Abstract PROCESS FOR CONVERTING RUTIN INTO A 3-O-ALKYL QUERCETIN. EXAMPLE: (A) RUTIN IS REACTED WITH AN EXCESS OF BENZOYL CHLORIDE TO BENZOYLATE ALL THE FREE PHENOLIC HYDROXY GROUPS OF THE RUTIN, THUS TO PRODUCE 5,7,3'',4''-TETRA-OBENZOYL RUTIN. (B) THIS COMPOUND IS THEN HYDROLYZED IN AN ACIDIC MEDIUM TO SPLIT OFF THE RUTINOSIDE GROUP WHILE RETAINING THE BENZOIC ACID GROUPS, THUS TO PRODUCE 5,7,3'',4''-TETRA-O-BENZOYL QUERCETIN. (C) THIS COMPOUND IS ALKYLATED TO PRODUCE 3-O-ALKYL-5,7,3'',4'' - TETRA - O BENZOYL QUERCETIN, WHICH IS THEN (D) HYDROLYZED TO YIELD THE FINAL PRODUCT 3-O-ALKYL QUERCETIN. ANOTHER PHASE OF THE DISCLOSURE CONCERNS THE CONVERSION OF RUTIN INTO 7-OBENZOYL QUERCETIN. THIS IS ACCOMPLISHED BY REACTING RUTIN WITH BENZOYL CHLORIDE IN THE PRESENCE OF BORAX TO CAUSE SELECTIVE BENZOYLATION OF THE RUTIN IN THE 7 POSITION. THE RESULTING INTEMEDIATE (7-O-BENZOYL RUTIN) IS THEN HYDROLYZED IN AN ACID MEDIUM, YIELDING THE DESIRED END PRODUCT 7-O-BENZOYL QUERCETIN.

Inventors

• 👤 Leonard Jurd

Bibliographic Details