Procedure for the preparation of 4-phenyl butyrate and uses thereof
Provided is a process for preparing 4-phenyl-1-butyric acid, comprising: reacting 4-phenyl-1-butanol with sodium chlorite, a nitroxyl radical catalyst and sodium hypochlorite in an organic solvent and a phosphate buffer; and quenching the reaction with sodium sulfite to produce 4-phenyl-1-butyric. Also provided is 4-phenyl-1-butyric acid prepared by such a process.
1. A process for preparing 4-phenyl-1-butyric acid, comprising:
reacting 4-phenyl-1-butanol with sodium chlorite, a nitroxyl radical catalyst and sodium hypochlorite in an organic solvent and a phosphate buffer; and quenching the reaction with sodium sulfite.
2. The process of claim 1 , wherein said reacting 4-phenyl-1-butanol with sodium chlorite, the nitroxyl radical catalyst and sodium hypochlorite in an organic solvent and a phosphate buffer comprises sequentially adding sodium chlorite and sodium hypochlorite to a mixture of 4-phenyl-1-butanol and the nitroxyl radical catalyst in an organic solvent and a phosphate buffer.
3. The process of claim 1 , wherein the nitroxyl radical catalyst is chosen from a TEMPO catalyst and an AZADO catalyst or a mixture thereof.
4. The process of claim 3 , wherein the TEMPO catalyst is chosen from TEMPO (a free radical of 2,2,6,6-tetramethyl-1-piperidinyloxy), 4-MeO-TEMPO (4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl); 4-acetoamido-TEMPO (4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxyl), and 4-hydroxy-TEMPO (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl).
5. The process of claim 3 , wherein the TEMPO catalyst is polymer-supported.
6. The process of claim 3 , wherein the AZADO catalyst is chosen from 2-azaadamantane N-oxyl (AZADO), 1-methyl-2-azaadamantane-N-oxyl (1-Me-AZADO), and 9-azanoradamantane N-oxyl (Nor-AZADO).
7. The process of claim 3 , wherein the nitroxyl radical catalyst is 9-azabicyclo[3.3.1]nonane N-oxyl (ABNO).
8. The process of claim 1 , wherein the organic solvent is selected from acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, diethyl ether, methyl tert-butyl ether, dimethoxyethane, 2-methoxyethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), toluene, benzene, hexane, pentane, dioxane, and mixtures thereof.
9. The process of claim 8 , wherein the organic solvent is acetonitrile.
10. The process of claim 1 , wherein the phosphate buffer comprises an aqueous solution of potassium phosphate monobasic and potassium phosphate dibasic.
11. The process of claim 10 , wherein potassium phosphate monobasic and potassium phosphate dibasic are each used in amounts of about 0.5 equivalent to about 1.5 equivalents.
12. The process of claim 1 , wherein the amount of the nitroxyl radical catalyst used is about 1.0 to about 50.0 mol percent.
13. The process of claim 12 , wherein the amount of the nitroxyl radical catalyst used is about 5.0 to 10.0 mol percent.
14. The process of claim 12 , wherein the amount of the nitroxyl radical catalyst used is about 7.0 mol percent.
15. The process of claim 1 , wherein the amount of sodium chlorite used is about 1 equivalent to about 3 equivalents.
16. The process of claim 15 , wherein the amount of sodium chlorite used is about 1.5 equivalent to about 2 equivalents.
17. The process of claim 16 , wherein the amount of sodium chlorite used is about 1.7 equivalents.
18. The process of claim 1 , wherein the sodium sulfite is aqueous sodium sulfite.
19. The process of claim 1 , wherein the sodium sulfite is solid sodium sulfite.
20. The process of claim 1 , wherein the amount of sodium sulfite used is about 1 to about 3 equivalents.