Synthesis of Isoflavone
The invention provides a process of manufacturing an isoflavone of the general formula 7 wherein R 1 , R 2 , R 3 , and R 4 each independently are H, OH, or an alkoxy, provided at least one of R 1 , R 2 , R 3 , and R 4 being OH, and one being alkoxy, or at least 2 groups being OH, comprising providing ketone (3) wherein R 1 , R 2 , R 3 , and R 4 are as stated above, combining (3) with trialkylortho formate, and a Lewis or Bronsted acid to produce the isoflavone, precipitating the isoflavone.
1 . A process of manufacturing an isoflavone of the general formula
wherein R 1 , R 2 , R 3 , and R 4 each independently are H, OH, or a C 1 -C 10 alkoxy, provided at least one of R 1 , R 2 , R 3 , and R 4 goups is OH, and another of R 1 , R 2 , R 3 , and R 4 groups is alkoxy or at least 2 groups being OH, said process comprising: (a) providing a ketone having formula 3
wherein R 1 , R 2 , R 3 , and R 4 groups are as stated above; (b) reacting said ketone with trialkylortho formate, and a Lewis or Bronsted acid to produce said isoflavone; and (c) precipitating said isoflavone.
2 . The process of claim 1 , wherein the isoflavone formed comprises
3 . The process of claim 1 , wherein the isoflavone formed comprises
4 . The process of claim 1 , wherein the isoflavone formed comprises
5 . The process of claim 1 , wherein the isoflavone formed comprises
6 . The process of claim 1 , wherein the isoflavone formed comprises
7 . The method of claim 1 , wherein formation of said ketone having formula 3 is carried out by combining phloroglucinol having formula 1
with a compound having formula 2
wherein R 5 comprises nitrile or an ester to produce said ketone.
8 . The process of claim 7 , wherein the compound having formula 2 comprises
and the ketone comprises
9 . The process of claim 1 , wherein a Lewis acid is used in the process and the Lewis acid comprises aluminum chloride or titanium chloride.
10 . The process of claim 1 , wherein a Bronsted acid is used in the process and the Bronsted acid comprises sulfuric acid.
11 . The process of claim 1 , wherein the trialkylortho formate comprises (CH 3 O) 3 CH.
12 . The process of claim 1 , wherein precipitating as carried out by addition of water.
13 . The process of claim 12 , further comprising recovering the isoflavone after precipitation.
14 . The process of claim 1 , wherein the alkoxy group in the compound having 7 is a C 1 -C 3 alkoxy.
15 . The process of claim 2 , wherein after the isoflavone is precipitated it is recovered by filtering and drying.
16 . The process of claim 1 , wherein the trialkyl orthoforamate comprises triethyl orthoformate.
17 . The process of claim 1 , wherein the isoflavone formed by the process is a 5,7 hydroxyisoflavone.
18 . The process of claim 1 , wherein the reacting is carried out in dimethylformamide.
19 . The process of claim 1 , wherein reacting is carried out in acetone.
20 . The process of claim 1 , wherein precipitation is carried out in ethanol.