Electrolytic carboxylation of carbon acids via electrogenerated bases
AssigneeMonsanto Company
InventorsRichard C. Hallcher, Manuel M. Baizer, Donald A. White
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Abstract
Electrolytic carboxylation of carbon acids via electrogenerated bases leads to carboxylated carbon acids.
Claims38
A process for electrolytic carboxylation of carbon acids via electrogenerated bases, which process comprises subjecting an anhydrous aprotic liquid electrolysis medium comprising such carbon acid, a base precursor more easily electro-reducible than either the carbon acid or carbon dioxide, anhydrous aprotic solvent, added carbon dioxide, and supporting electrolyte to electrolysis at a cathode potential sufficiently negative to effect electro-reduction of the base precursor to the corresponding electrogenerated base but insufficiently negative to effect electro-reduction of either the carbon acid, added carbon dioxide, anhydrous aprotic solvent, or supporting electrolyte of the electrolysis medium, and thereafter recovering a carboxylated carbon acid.
A process for conducting the electrolytic carboxylation of carbon acids in an anhydrous aprotic liquid electrolysis medium containing such carbon acid, a base precursor, an anhydrous aprotic solvent, added carbon dioxide, and supporting electrolyte, which process comprises:
- (a) electrogenerating a base from the base precursor;
- (b) allowing the electrogenerated base to react with the carbon acid to abstract at least one proton and produce a carbon acid anion and the conjugate acid of the electrogenerated base;
- (c) allowing the carbon acid anion to react with the added carbon dioxide to form a carboxylated carbon acid;
- and
- (d) recovering the carboxylated carbon acid.
The process of claim 38 wherein the conjugate acid of the electrogenerated base is oxidized to the base precursor and recycled.
A process for oxidation of ethane-1,1,2,2-tetracarboxylate tetraesters to ethenetetracarboxylate tetraesters, which comprises contacting the ethane-1,1,2,2-tetracarboxylate tetraester, dissolved in an anhydrous aprotic solvent containing a scavenger capable of capturing protons, with molecular bromine.
The process of preparing a methoxymethane-1,1,1'-tricarboxylate, which process comprises:
- (a) conducting the electrolytic carboxylation of an N-alkyldiglycolimide via an electrogenerated base in an anhydrous aprotic medium to produce an N-alkyldiglycolimide-3-carboxylate;
- (b) converting the N-alkyldiglycolimide-3-carboxylate to the methoxymethane-1,1,1'-tricarboxylate by hydrolysis;
- and
- (c) recovering the methoxymethane-1,1,1'-tricarboxylate.
A process for carboxylation of the N-methyldiglycolimide anion which comprises allowing the N-methyldiglycolimide anion to react with added carbon dioxide to form the 4-methyl-3,5-dioxo-6H,1,4-oxazine-2,O.sup.3 -dicarboxylate.
A solution suitable for conducting the electrolytic carboxylation of carbon acids via electrogenerated bases, which comprises an anhydrous aprotic solvent, an alkali metal bromide, and a crown ether.
A solution suitable for conducting the electrolytic carboxylation of carbon acids in electrogenerated bases, which comprises an anhydrous aprotic solvent, a quaternary ammonium bromide, an alkali metal bromide, and a crown ether.
A solution comprising an anhydrous aprotic solvent, a quaternary ammonium bromide, an alkali metal bromide, a crown ether, and dissolved in the solution N-methyldiglycolimide, an ethenetetracarboxyklate tetraester, and carbon dioxide.
A semi-continuous electrolytic carboxylation of carbon acids via electrogenerated bases process which comprises:
- (a) charging to the cathode compartment of a divided electrolysis cell a catholyte medium comprising a carbon acid, a base precursor, an anhydrous aprotic solvent, and added carbon dioxide.
- (b)charging to the anode compartment of the divided electrolysis cell an anolyte medium comprising the conjugate acid of the electrogenerated base generated from the base precursor, the anhydrous aprotic solvent, supporting electrolyte, and a scavenger.
- (c) passing a direct electric current through the electrolysis cell to produce a carboxylated carbon acid and the conjugate acid of the electrogenerated base in the catholyte, and the base precursor and an innocuous scavenger reaction product in the anolyte;
- (d) recovering the carboxylated carbon acid from the catholyte;
- (e) removing the unreacted scavenger and the innocuous scavenger reaction product from the anolyte;
- (f) charging to the anode compartment the catholyte from step (d) containing the conjugate acid of the electrogenerated base, with added scavenger;
- (g) charging to the cathode compartment the anolyte from step (e) containing the base precursor, with added carbon acid;
- and
- (h) repeating steps (c) through (h).
Dependencies are inferred from the claim text.