Process for the preparation of alkyl 5-(dicarboximido) levulinate and alkyl 4-oxo-pentenoate
A method of manufacturing esters of dicarboxyimidolevulinic acid and alkyl trans-4-oxo-2-pentenoate. This method includes two reaction steps, wherein the first step of said two reaction steps is a bromination of alkyl-levulinate, to obtain alkyl-(3 and 5)-bromolevulinate, and the second step of said two reaction steps is a synthesis of esters of dicarboxyimidolevulinic acid and alkyl trans-4-oxo-2-pentenoate, by reacting the alkyl-(3 and 5)-bromolevulinate obtained in said first step with dicarboxyimide anion.
1. A method of manufacturing esters of dicarboxyimidolevulinic acid and alkyl trans-4-oxo-2-pentenoate, comprising a first step of bromination of alkylic levulinate, to obtain a mixture of alkyl-3-bromolevulinate and alkyl-5-bromolevulinate, and a second step of synthesis of esters of dicarboxyimidolevulinic acid and alkyl trans-4-oxo-2-pentenoate, by reacting the alkyl-3-bromolevulinate/alkyl-5-bromolevulinate mixture, obtained in said first step, with a dicarboxylmide anion, and a third step of separation of esters of dicarboxyimidolevulinic acid and alkyl trans-4-oxo-2-pentenoate.
2. Method according to claim 1 , wherein said dicarboxylmide is phtalimide, 1,8 naphtalimide, maleimide, hydantoin, diphenicimide, or succinimide, whereby said synthesized esters of dicarboxyimidolevulinic acid is esters of δ-phtalimidolevulinic acid, esters of 1,8 naphtalimidolevulinic acid, esters of maleimidolevulinic acid, esters of hydantionlevulinic acid, esters of diphenicimidolevulinic acid, or esters of succinimidolevulinic acid.
3. Method according to claim 1 , wherein said alkyl is methyl or ethyl.
4. Method according to claim 1 , wherein said separation is performed by precipitation in a water solution.
5. Method according to claim 4 , wherein said esters of dicarboxyimidolevulinic acid are obtained in a precipitation after said precipitation in water.
6. Method according to claim 4 , wherein said alkyl trans-4-oxo-2-pentenoate is obtained in said water solution.
7. Method according to claim 6 , wherein said alkyl trans-4-oxo-2-pentenoate is extracted from said water solution.
8. Method according to claim 7 , wherein said extraction is performed with ethylacetate.
9. Method according to claim 8 , followed by evaporation of said ethylacetate.
10. Method according to claim 4 , wherein esters of dicarboxyimidolevulinic acid are purified by trituration with toluene, followed by evaporation of said toluene.
11. A method of manufacturing esters of dicarboxyimidolevulinic acid and alkyl trans-4-oxo-2-pentenoate, comprising a first step of bromination of alkylic levulinate, achieved by adding bromine to a refluxing levulinic acid solution at the approximate rate of disappearance of the bromine and wherein the bromination reaction time is approximately 25 minutes to obtain a mixture of alkyl-3-bromolevulinate and alkyl-5-bromolevulinate, and a second step of synthesis of esters of dicarboxyimidolevulinic acid and alkyl trans-4-oxo-2-pentenoate, by reacting the alkyl-3-bromolevulinate/alkyl-5-bromolevulinate mixture, obtained in said first step, with a dicarboxylmide anion.
12. Method according to claim 11 , wherein said dicarboxylmide is phtalimide, 1,8 naphtalimide, maleimide, hydantoin, diphenicimide, or succinimide, whereby said synthesized esters of dicarboxyimidolevulinic acid is esters of δ-phtalimidolevulinic acid, esters of 1,8 naphtalimidolevulinic acid, esters of maleimidolevulinic acid, esters of hydantionlevulinic acid, esters of diphenicimidolevulinic acid, or esters of succinimidolevulinic acid.
13. Method according to claim 11 , wherein said alkyl is methyl or ethyl.
14. Method according to claim 11 , comprising a third step of separation of esters of dicarboxyimidolevulinic acid and alkyl trans-4-oxo-2-pentenoate.
15. Method according to claim 14 , wherein said esters of dicarboxyimidolevulinic acid are obtained in a precipitation in water.
16. Method according to claim 14 , wherein alkyl trans-4-oxo-2-pentenoate is obtained in said water solution.
17. Method according to claim 16 , wherein said alkyl trans-4-oxo-2-pentenoate is extracted from said water solution.
18. Method according to claim 17 , wherein said extraction is performed with ethylacetate.
19. Method according to claim 18 , followed by evaporation of said ethylacetate.
20. Method according to claim 14 , wherein esters of dicarboxyimidolevulinic acid are purified by trituration with toluene, followed by evaporation of said toluene.
21. The method of claim 11 , wherein said bromine is added step-wise to the refluxing levulinic acid solution.
22. The method of claim 11 , wherein said bromine is added continuously to the refluxing levulinic acid solution.
23. The method of claim 11 , wherein the yield of alkyl-3-bromolevulinate and alkyl-5-bromolevulinate is greater than 90%.