Electrochemical process for production of tetraalkyl 1,2,3,4-butanetetracarboxylates

Patent metadata

Field	Value
Publication number	US-12590375-B2
Application number	US-202519010449-A
Country	US
Kind code	B2
Filing date	Jan 6, 2025
Priority date	Jan 11, 2024
Publication date	Mar 31, 2026
Grant date	Mar 31, 2026

Abstract

An electrochemical process produces tetraalkyl 1,2,3,4-butanetetracarboxylates having alkyl groups with 1 to 6 carbon atoms. The process employs an electrohydrodimerization of dialkyl maleates having alkyl groups having 1 to 6 carbon atoms in a reactant solution with an alcohol and a conducting salt.

First claim

The invention claimed is:

1 . A process for producing tetraalkyl 1,2,3,4-butanetetracarboxylates containing alkyl groups having 1 to 6 carbon atoms by electrohydrodimerization in at least one reaction zone comprising an anode and a cathode with a reactant solution comprising dialkyl maleates containing alkyl groups having 1 to 6 carbon atoms, at least one monohydric alcohol having 1 to 6 carbon atoms, and a conducting salt, the process comprising:
electrohydrodimerizing the dialkyl maleates to afford tetraalkyl 1,2,3,4-butanetetracarboxylates at the cathode, wherein the anode and the cathode employed are boron-doped diamond electrodes.

2 . The process according to claim 1 , wherein the number of carbon atoms of the alkyl groups of the dialkyl maleates and the number of carbon atoms of the at least one monohydric alcohol are identical.

3 . The process according to claim 1 , comprising:
employing said conducting salt having tetraalkylammonium cations and/or alkali metal cations and having anions selected from the group consisting of aromatic-substituted sulfonates, alkylsulfonates, acetates, perchlorates, tetrafluoroborates, tetraphenylborates, bromides, iodides, phosphates, phosphonates, sulfates, alkylsulfates, and hexafluorophosphates.

4 . The process according to claim 1 , wherein the tetraalkyl 1,2,3,4-butanetetracarboxylates and the dialkyl maleates each have alkyl groups having 5 carbon atoms.

5 . The process according to claim 1 , wherein the at least one monohydric alcohol is methanol, butanol or a pentanol.

6 . The process according to claim 1 , further comprising:
employing, in the electrohydrodimerization, a cosolvent selected from the group consisting of acetonitrile, dimethyl sulfoxide, tetrahydrofuran, dioxane, propylene carbonate, N,N-dimethylformamide, organic carbonates, dichloromethane, chloroform and acetone.

7 . The process according to claim 1 , comprising:
performing the electrohydrodimerization at a temperature in a range from 20° C. to 80° C.

8 . The process according to claim 1 , comprising;
performing the electrohydrodimerization at a pressure of 0.5 to 3 bar.

9 . The process according to claim 1 ,
wherein said at least one reaction zone comprises an electrolysis cell, wherein a flow rate in the electrolysis cell is in a range between 50 and 700 l/h per 100 cm 2 of electrode surface area.

10 . The process according to claim 1 , comprising:
reacting the at least one monohydric alcohol having 1 to 6 carbon atoms to afford an aldehyde at the anode during the process.

11 . The process according to claim 10 , comprising:
forming valeraldehyde and 2-methylbutanal, when employing pentanol as the monohydric alcohol.

12 . The process according to claim 1 , comprising:
producing, by the electrohydrodimerization, the tetraalkyl 1,2,3,4-butanetetracarboxylates as tetramethyl 1,2,3,4-butanetetracarboxylate, and subsequently transesterifying the tetramethyl 1,2,3,4-butanetetracarboxylate with at least one monohydric alcohol having 2 to 6 carbon atoms to afford tetraalkyl 1,2,3,4-butanetetracarboxylates containing alkyl groups having 2 to 6 carbon atoms.

13 . The process according to claim 12 , comprising:
performing the transesterification at a temperature of 100° C. to 300° C.

14 . The process according to claim 1 , comprising:
producing, by the electrohydrodimerization, the tetraalkyl 1,2,3,4-butanetetracarboxylates as tetraethyl 1,2,3,4-butanetetracarboxylate, and subsequently transesterifying the tetraethyl 1,2,3,4-butanetetracarboxylate with at least one monohydric alcohol having 3 to 6 carbon atoms to afford tetraalkyl 1,2,3,4-butanetetracarboxylates containing alkyl groups having 3 to 6 carbon atoms.

Assignees

• Evonik Oxeno Gmbh & Co Kg

Inventors

• Grass Michael
• Kraft Johannes
• Van Eickels Michael
• Arndt Sebastian
• Hoppe Carl-Friedrich
• Becker Stephan
• Bremer David Sascha

Classifications

• C25B11/043

  Carbon, e.g. diamond or graphene · CPC title

• C25B3/295 Primary

  hydrodimerisation · CPC title

• C07C69/34

  Esters of acyclic saturated polycarboxylic acids having an esterified carboxyl group bound to an acyclic carbon atom · CPC title

• C07C67/03

  by reacting an ester group with a hydroxy group · CPC title

• C25B3/23

  Oxidation (halogenation C25B3/27) · CPC title