Process for the oxidation of fatty acids
12291692 ยท 2025-05-06
Assignee
Inventors
- Amol Arvind KULKARNI (Pune, IN)
- Dumbala Srinivasa Reddy (Pune, IN)
- Paresh Ramesh ATHAWALE (Pune, IN)
- Ranjit Shabu ATAPALKAR (Pune, IN)
Cpc classification
International classification
Abstract
The present invention discloses a process for the oxidation of fatty acids comprises reacting fatty acid with O.sub.2 containing O.sub.3 for a period of 0.1-60 min at a temp in the range of 78 to 30 deg C. to obtain the corresponding products, wherein the conversion of the fatty acid is in the range of 80% to 100% and the process is catalyst free and co-oxidant free.
Claims
1. A process for the oxidation of a fatty acid comprising: reacting, in a solvent, a fatty acid having a carbon-carbon double bond with O.sub.2 containing ozone for a time period ranging from 2 to 60 minutes at a temperature ranging from 78 C. to 30 C. to obtain a product comprising a second fatty acid and a dicarboxylic acid, wherein the percent conversion of the fatty acid to the product ranges from 80% to 100%, the solvent is selected from the group consisting of ethanol, methanol, acetone, isopropanol, n-butanol, ethyl acetate, dichloromethane, water and any combination thereof, and the process is catalyst-free and co-oxidant-free.
2. The process of claim 1, wherein the process is carried out in a batch mode or in a continuous mode.
3. The process of claim 1, wherein the fatty acid having a carbon-carbon double bond is oleic acid.
4. The process of claim 1, wherein said product the second fatty acid is nonanoic acid and the dicarboxylic acid is azelaic acid.
5. A process for the synthesis of azelaic acid by oxidation of oleic acid in a batch mode, the process comprising: a) dissolving an oleic acid in a solvent to obtain a solution; b) purging O.sub.2 containing O.sub.3 into the solution at a temperature ranging from 15 C. to 0 C. for a time period ranging from 5 to 60 minutes to produce a mixture of azelaic acid and nonanoic acid; and c) continuing purging of oxygen at a temperature ranging from 15 C. to 0 C. for 30 minutes to remove unreacted ozone, wherein the percent conversion of the oleic acid to the mixture of azelaic acid and nonanoic acid is in the range of 80 to 100%, the solvent is selected from the group consisting of ethanol, methanol, acetone, isopropanol, n-butanol, ethyl acetate, dichloromethane, water and any combination thereof, and the process is catalyst-free and co-oxidant-free.
6. A process for the synthesis of azelaic acid by oxidation of oleic acid in a continuous mode, the process comprising: a) dissolving an oleic acid in a solvent to form an oleic acid solution; b) pumping O.sub.2 containing O.sub.3 in a flow reactor; c) pumping the oleic solution of step (a) by keeping a gas phase to liquid phase volume flow rate ratio of 25:2500; and d) continuing pumping O.sub.2 containing O.sub.3 in the flow reactor without changing the liquid phase volume flow rate ratio with the temperature of the flow reactor ranging from 10 C. to 10 C. to produce a mixture of azelaic acid and nonanoic acid, wherein the percent conversion of oleic acid to a mixture of azelaic acid and nonanoic acid ranges from 80% to 100%, the solvent is selected from the group consisting of ethanol, methanol, acetone, isopropanol, n-butanol, ethyl acetate, dichloromethane, water and any combination thereof, and the process is catalyst-free and co-oxidant-free.
7. The process of claim 6, wherein the solvent is a mixture of dichloromethane and methanol in a weight ratio ranging from 1:20 to 20:1.
8. The process of claim 1, wherein the solvent is a mixture of dichloromethane and methanol in a weight ratio ranging from 1:20 to 20:1.
9. The process of claim 1, wherein the solvent is a mixture of acetone and water in a weight ratio ranging from 1:20 to 20:1.
10. The process of claim 1, wherein the solvent is a mixture of isopropanol and water in a weight ratio ranging from 1:20 to 20:1.
11. The process of claim 5, wherein the solvent is a mixture of dichloromethane and methanol in a weight ratio ranging from 1:20 to 20:1.
12. The process of claim 5, wherein the solvent is a mixture of acetone and water in a weight ratio ranging from 1:20 to 20:1.
13. The process of claim 5, wherein the solvent is a mixture of isopropanol and water in a weight ratio ranging from 1:20 to 20:1.
14. The process of claim 6, wherein the solvent is a mixture of isopropanol and water in a weight ratio ranging from 1:20 to 20:1.
15. The process of claim 6, wherein the solvent is a mixture of acetone and water in a weight ratio ranging from 1:20 to 20:1.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
DETAILED DESCRIPTION OF THE INVENTION
(3) The present invention provides a process for the oxidation of fatty acids.
(4) The present invention provides a process for the oxidation of fatty acids comprises reacting a fatty acid with O.sub.2 containing ozone (O.sub.3) for a period of 0.1-60 min at a temp in the range of 78 to 30 deg C. to obtain the corresponding products, wherein the conversion of the fatty acid is in the range of 80% to 100% and the process is catalyst free and co-oxidant free.
(5) The process is carried out in batch or continuous (flow) mode.
(6) The present invention provides a process for the oxidation of the oleic acid to afford azelaic acid wherein the reaction is carried out in batch or continuous (flow) mode.
(7) The present invention provides a process for the synthesis of azelaic acid in batch mode comprising the steps of: a) dissolving an oleic acid in a solvent to obtain a solution; b) purging O.sub.2 containing O.sub.3 into the solution of step (a) at a temperature in the range of 15 C. to 0 C. for a time period in the range of 5 to 60 minutes to afford mixture of azelaic acid and nonanoic acid and c) continuing purging of oxygen at a temperature in the range of 15 C. to 0 C. for 30 minutes to remove traces of unreacted ozone.
(8) The solvent of step (a) is selected from the group consisting of ethanol, methanol, acetone, i-propanol, n-butanol, dichloromethane, ethyl acetate and water either alone or in combination thereof.
(9) The solvent is selected from dichloromethane:methanol, acetone:water in the ratio of 0:20 to 20:0.
(10) The conversion of oleic acid is in the range of 80% to 100%.
(11) The quantitative yield of mixture of azelaic acid and nonanoic acid is 100%. (Refer
(12)
(13)
(14) From
(15) The process for the synthesis of Azelaic acid in batch mode is carried out at different conditions. Results are summarized in following table 1:
(16) TABLE-US-00001 TABLE 1 Purging Co-oxidant Yield of Wt of time of used and mixture of oleic O.sub.2 stirring Azelaic acid Ex. acid in containing time after and No. gm solvent catalyst temp O.sub.3 afteraddition Nonaicacid 1 1 dichloro meth- acetic 78 C. 5 min 5 ml H.sub.2O.sub.2 90% ane:methanol acid and 30 min (1:1) 2 0.5 acetone:water Me.sub.2S 0 C. 5 min 20 ml Jones 93% (95:5 mL) reagents (i.e CrO3, aq. H.sub.2SO.sub.4, Acetone water mixture) and 3 hrs 3 1 acetone:water CuCl 0 C. 5 min 30% H.sub.2O.sub.2 93% (95:5 mL) (5 mol %) and 24 hours 4 0.5 acetone:water CuCl 0 C. 10 min NaOCl (5 No (47.5:2.5 mL) (5 mol %) mol %) and formation 50 min. of desired product 5 1 acetone:water CuCl 0 C. 10 min No oxidant 83% (47.5:2.5 mL) (20 mol %) but purging of oxygen for 30 min. 6 5 acetone:water No catalyst 0 C. 10 min No oxidant 100% (118.75:6.25 mL) but purging of oxygen for 30 min
(17) Entries 1 to 5 of table 1 show the comparative examples for the present invention. From the table 1, it is observed that catalyst and co-oxidant are used for oxidation of oleic acid and yield of azelaic acid and nonanoic acid is in the range of 80 to 93% but from entry 6 it is observed that oxidation of oleic acid is carried out without using catalyst and co-oxidant and gives 100% yield of azelaic acid and nonanoic acid.
(18) The present invention provides a process for the synthesis of azelaic acid in continuous mode comprising the steps of: a) dissolving an oleic acid in solvent to form oleic acid solution; b) pumping O.sub.2 containing O.sub.3 in a flow reactor; c) pumping the oleic solution of step (a) by keeping a gas phase to liquid phase flow rate ratio of 25 to 2500 and d) continuing pumping of O.sub.2 containing O.sub.3 in a flow reactor without changing the flow ratio as mentioned in step (c) wherein temperature of the flow reactor is in the range of 10 C. to 10 C. to afford azelaic acid and nonanoic acid.
(19) The solvent is selected from ethanol, methanol, acetone, isopropyl alcohol, n-butanol, ethyl acetate, dichloromethane and water alone or in combination thereof.
(20) The solvent is selected from dichloromethane:methanol, isopropyl alcohol:water and acetone:water in the ratio of 0:20 to 20:0.
(21) The conversion of oleic acid is in the range of 80% to 100%.
(22) The quantity of O.sub.2 containing O.sub.3 is depending upon the quantity of oleic acid is taken.
(23) The volume ratio of O.sub.2 containing O.sub.3:Oleic acid is 25:2500.
(24) The quantitative yield of mixture of azelaic acid and nonanoic acid is 100%. (Refer
(25)
(26)
(27) From
(28) The process for the synthesis of azelaic acid in continuous mode is carried out at different conditions. Results are summarized in following table 2:
(29) TABLE-US-00002 TABLE 2 Flow rate ratio of gas Solvent phase (O.sub.2 containing Wt of composition O.sub.3) flow rate to liquid Yield of oleic (volume ratio of phase flow rate (oleic azelaic acid acid in organic phase to acid dissolved in Temp. of and nonanoic Exp. No. gm water) solvent) reactor acid 7 1 acetone:water mixture (9) 500 0 C. 81% 8 2 acetone:water mixture (9) 500 0 C. 93% 9 5 acetone:water (19) 500 0 C. 93% 10 1 acetone:water (9) 100 0 C. 92% 11 1 acetone:water (9) 50 0 C. 80% 12 1 acetone:water (9) 25 0 C. <5% 13 1 acetone:water (9) 100 mL/min 10 C. 87% 14 1 acetone:water (9) 100 mL/min 10 C. 94%
(30) In still yet another embodiment, the present invention provides impurity free, catalyst free and co-oxidant free process for the oxidation of fatty acids.
(31) The present invention provides impurity free, catalyst free and co-oxidant free process for the oxidation of oleic acid to afford only product of azelaic acid and nonionic acid. No other impurity is formed. (Refer
(32) From
EXAMPLES
(33) Following examples are given by way of illustration therefore should not be construed to limit the scope of the invention.
Example 1: Synthesis of Azelaic Acid with Catalyst and Co-Oxidant
(34) 1 gm oleic acid was dissolved in dichloromethane:methanol (1:1) to form the solution of oleic acid. 5 mL acetic acid as a catalyst was added into the oleic acid solution. The temperature of the reaction mixture was set at 78 C. and O.sub.2 containing O.sub.3 was purged into the oleic acid solution for 5 min. 5 ml H.sub.2O.sub.2 oxidant was added into the purged solution. The reaction mixture was stirred for 30 min. After completion of the reaction, work up procedure was followed to obtain mixture of azelaic acid and nonanoic acid. Azelaic acid and Nonanoic acid were separated and recovered by extraction and decantation method. It resulted in 90% yield mixture of azelaic acid and nonanoic acid.
Example 2: Synthesis of Azelaic Acid with Catalyst and Co-Oxidant
(35) 0.5 gm oleic acid was dissolved in acetone:water (95:5 mL) to form the solution of oleic acid. 3 mL Me.sub.2S, 2 eq. as a catalyst was added into the oleic acid solution. The temperature of the reaction mixture was set at 0 C. and O.sub.2 containing O.sub.3 was purged into the oleic acid solution for 5 min. 20 ml (Jones reagent, i.e CrO.sub.3, aq. H.sub.2SO.sub.4, Acetone and water mixture) oxidant was added into the purged solution. The reaction mixture was stirred for 3 hrs. After completion of the reaction, work up procedure was followed to obtain mixture of azelaic acid and nonanoic acid. azelaic acid and nonanoic acid were separated and recovered by extraction and decantation method. It resulted in 93% yield mixture of azelaic acid and nonanoic acid.
Example 3: Synthesis of Azelaic Acid with Catalyst and Co-Oxidant
(36) 1 gm oleic acid was dissolved in acetone:water (95:5 mL) to form the solution of oleic acid. 18 mg CuCl (5 mol %), as a catalyst was added into the oleic acid solution. The temperature of the reaction mixture was set at 0 C. and O.sub.2 containing O.sub.3 was purged into the oleic acid solution for 5 min. 1.2 mL (30% H.sub.2O.sub.2) 1 eq. oxidant was added into the purged solution. The reaction mixture was stirred for 24 hrs. After completion of the reaction, work up procedure was followed to obtain mixture of azelaic acid and nonanoic acid. Azelaic acid and nonanoic acid were separated and recovered by extraction and decantation method. It resulted in 93% yield mixture of azelaic acid and nonanoic acid.
Example 4: Synthesis of Azelaic Acid with Catalyst and Co-Oxidant
(37) 0.5 gm oleic acid was dissolved in acetone:water (47.5:2.5 mL) to form the solution of oleic acid, 18 mg CuCl (5 mol %), as a catalyst was added into the oleic acid solution. The temperature of the reaction mixture was set at 0 C. and O.sub.2 containing O.sub.3 was purged into the oleic acid solution for 10 min. 3 mL NaOCl (5 mol %), 2 eq. oxidant was added into the purged solution. The reaction mixture was stirred for 50 min. The reaction did not show any formation of the desired product.
Example 5: Synthesis of Azelaic Acid with Catalyst
(38) 1 gm oleic acid was dissolved in acetone:water (47.5:2.5 mL) to form the solution of oleic acid, 18 mg CuCl (5 mol %), as a catalyst was added into the oleic acid solution. The temperature of the reaction mixture was set at 0 C. and O.sub.2 containing O.sub.3 was purged into the oleic acid solution for 10 min. Oxygen was purged for 30 min. After completion of the reaction, work up procedure was followed to obtain mixture of azelaic acid and nonanoic acid. azelaic acid and nonanoic acid were separated and recovered by extraction and decantation method. It resulted in 83% yield mixture of azelaic acid and nonanoic acid.
Example 6: Synthesis of Azelaic Acid with O.SUB.2 .Containing O.SUB.3
(39) 5 gm oleic acid was dissolved in acetone:water (118.75:6.25 mL) to form the solution of oleic acid. The temperature of the reaction mixture was set at 0 C. and O.sub.2 containing O.sub.3 was purged into the oleic acid solution for 10 min. Oxygen was purged for 30 min. After completion of the reaction, work up procedure was followed to obtain mixture of azelaic acid and nonanoic acid.
(40) Azelaic acid and nonanoic acid were separated and recovered by extraction and decantation method. It resulted in 100% yield mixture of azelaic acid and nonanoic acid.
Example 7: Synthesis of Azelaic Acid in Flow Reactor
(41) 1 gm oleic acid was dissolved in acetone:water mixture (95 ml:5 ml), O.sub.2 containing O.sub.3 and the oleic acid solution were pumped at the flow rate ratio of 400, in a flow reactor (volume=20 mL, inner diameter=2 mm, length 5 m) at 0 C. The sample obtained from outlet was analyzed and analysis showed 81% azelaic acid and nonanoic acid (mixture).
Example 8: Synthesis of Azelaic Acid in Flow Reactor
(42) 2 gm oleic acid was dissolved in acetone:water mixture (95 ml: 5 ml), O.sub.2 containing O.sub.3 and the oleic acid solution were pumped at the flow rate ratio of 400, in a flow reactor (volume=20 mL, inner diameter=2 mm, length 5 m) at 0 C. The sample obtained from outlet was analyzed and analysis showed 93% azelaic acid and nonanoic acid (mixture).
Example 9: Synthesis of Azelaic Acid in Flow Reactor
(43) 5 gm oleic acid was dissolved in acetone:water mixture (118.75:6.25 mL), O.sub.2 containing O.sub.3 and the oleic acid solution were pumped at the flow rate ratio of 400, in a flow reactor (volume=20 mL, inner diameter=2 mm, length 5 m) at 0 C. The sample obtained from outlet was analyzed and analysis showed 93% azelaic acid and nonanoic acid (mixture).
Example 10: Synthesis of Azelaic Acid in Flow Reactor
(44) 1 gm oleic acid was dissolved in acetone:water mixture (95 ml:5 ml), O.sub.2 containing O.sub.3 and the oleic acid solution were pumped at the flow rate ratio of 100, in a flow reactor (volume=20 mL, inner diameter=2 mm, length 5 m) at 0 C. The sample obtained from outlet was analyzed and analysis showed 92% azelaic acid and nonanoic acid (mixture).
Example 11: Synthesis of Azelaic Acid in Flow Reactor
(45) 1 gm oleic acid was dissolved in acetone:water mixture (95 ml:5 ml), O.sub.2 containing O.sub.3 and the oleic acid solution are pumped at the flow rate ratio of 50, in a flow reactor (volume=20 mL, inner diameter=2 mm, length 5 m) at 0 C. The sample obtained from outlet was analyzed and analysis showed 80% azelaic acid and nonanoic acid (mixture).
Example 12: Synthesis of azelaic acid in flow reactor
(46) 1 gm oleic acid was dissolved in acetone:water mixture (95 ml:5 ml), O.sub.2 containing O.sub.3 and the oleic acid solution are pumped at the flow rate ratio of 25, in a flow reactor (volume=20 mL, inner diameter=2 mm, length 5 m) at 0 C. The sample obtained from outlet was analyzed and analysis showed less than 5% azelaic acid and nonanoic acid (mixture).
Example 13: Synthesis of azelaic acid in flow reactor
(47) 1 gm oleic acid was dissolved in acetone:water mixture (45 ml:5 ml), O.sub.2 containing O.sub.3 and the oleic acid solution are pumped at the flow rate ratio of 100, in a flow reactor (volume=20 mL, inner diameter=2 mm, length 5 m) at 10 C. The sample obtained from outlet was analyzed and analysis showed 87% azelaic acid and nonanoic acid (mixture).
Example 14: Synthesis of azelaic acid in flow reactor
(48) 1 gm oleic acid was dissolved in acetone:water mixture (45 ml:5 ml), O.sub.2 containing O.sub.3 and the oleic acid solution are pumped at the flow rate ratio of 100, in a flow reactor (volume=20 mL, inner diameter=2 mm, length 5 m) at 10 C. The sample obtained from outlet was analyzed and analysis showed 94% azelaic acid and nonanoic acid (mixture).
Advantages of the Invention
(49) 1. The yield of azelaic acid and nonanoic acid mixture is 100%. 2. Reaction is catalyst free. 3. Reaction is co-oxidant free. 4. Reaction is impurity free 5. Reaction time is in few seconds to few minutes, with 80-100% conversion of oleic acid to form azelaic acid and nonanoic acid.