# US 5,350,872 A · Process for the preparation of carboxylic acids and derivatives of them

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- Number: US 5,350,872 A
- Document ID: US5350872A
- Status: Granted
- Kind: A
- Application number: 08/143,124
- Filed: 1993-10-29
- Granted: 1994-09-27
- Earliest claimed: 1992-08-11
- Assignees: Biogal Gyogyszergrar
- Inventors: Gyorgy Toth; Janos Balint; Klara Elek nee Herczik; Zsuzsanna Moricz nee Garai; Eva Mudra nee Kantor
- Web page: https://patentgrep.com/patent/US5350872A

## CPC

- C07C 67/317: by splitting-off hydrogen or functional groups; by hydrogenolysis of functional groups
- C07C 51/09: from carboxylic acid esters or lactones
- C07C 67/32: Decarboxylation
- C07C 67/343: by increase in the number of carbon atoms
- C07C 201/12: by reactions not involving the formation of nitro groups
- C07C 227/02: Formation of carboxyl groups in compounds containing amino groups, e.g. by oxidation of amino alcohols
- C07C 319/20: by reactions not involving the formation of sulfide groups
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

The subject matter of the invention is a process for the preparation of carboxylic acids and derivatives of them of the general formula ##STR1## wherein R means hydrogen, or a C.sub.1-4 alkyl or a (C.sub.1-5 alkoxy)carbonyl group, R.sub.1 is as defined in claim 1, R.sub.7 stands for hydrogen or a C.sub.1-7 alkyl group and R.sub.8 means hydrogen or a carboxyl group, by reacting a 1,3-dioxane-4,6-dione derivative of the general formula ##STR2## wherein R.sub.9 stands for a C.sub.1-4 alkyl group or a phenyl group, optionally monosubstituted by halogen and R.sub.10 stands for hydrogen or a C.sub.1-5 alkyl group or R.sub.9 and R.sub.10 together form a pentamethylene group, and an aldehyde or ketone of the general formula ##STR3## in the presence of formic acid.

## Claims

### Claim 1

A process for the preparation of carboxylic acids, and their derivatives, of the formula ##STR18## wherein R means hydrogen, or a C.sub.1-4 alkyl or a (C.sub.1-5 alkoxy)carbonyl group,
R.sub.1 stands for a C.sub.1-6 alkyl group, a (C.sub.1-5 alkoxy)-carbonyl group, a (C.sub.1-5 alkyl)carbonyl group, a (C.sub.1-5 alkoxy)carbonyl(C.sub.1-5 alkyl) group, a phenyl group, optionally monosubstituted by a C.sub.1-4 alkyl or C.sub.2-4 alkenyl group, di- or tri- substituted by C.sub.1-4 alkoxy groups, monosubstituted by a nitro group, disubstituted by C.sub.1-4 alkoxy and hydroxy groups, monosubstituted by a C.sub.1-4 alkylthio group, mono-or disubstituted by one or two di(C.sub.1-4 alkyl) amino groups or monosubstituted by halogen, for a furyl group, for a thiofuryl group, for a thienyl group, or for a group of the formula ##STR19## or R and R.sub.1 together form a straight-chain C.sub.4-5 alkylene group, R.sub.7 stands for hydrogen or a C.sub.1-7 alkyl group and
R.sub.8 means hydrogen or a carboxyl group,
which process comprises reacting a 1,3-dioxane-4,6-dione derivative of the formula ##STR20## wherein R.sub.9 stands for a C.sub.1-4 alkyl group or a phenyl group, optionally monosubstituted by halogen, and
R.sub.10 stands for hydrogen or a C.sub.1-5 alkyl group, or
R.sub.9 and R.sub.10 together form a pentamethylene group,
and an aldehyde or ketone of the formula ##STR21## wherein R and R.sub.1 are as defined above,
in the presence of formic acid and of 1 or more members selected from the group consisting of secondary amines and tertiary amines and, optionally of an alcohol of the formula
R.sub.7 --OH VI,
wherein
R.sub.7 is a C.sub.1-7 alkyl group,
at a temperature of 20.degree. to 140.degree. C. optionally in the presence of an inert organic solvent.

### Claim 2 (depends on 1)

The process of claim 1, wherein the inert organic solvent is at least one member selected from the group consisting of benzene, dimethylformamide, acetonitrile, and ethyl acetate.

### Claim 3 (depends on 1)

The process of claim 1, wherein the amine is at least one member selected from the group consisting of di-(C.sub.1-4 alkyl)amine, tri-(C.sub.1-4 alkyl)amine and cyclic amine.

### Claim 4 (depends on 1)

The process of claim 1, wherein the amine is at least one member selected from the group consisting of dimethylamine, diethylamine, methylethylamine, triethylamine, pyridine, piperidine, N-(C.sub.1-4 alkyl)-piperidine, and morpholine.

### Claim 5 (depends on 4)

The process of claim 4, wherein the amine is n-ethylpiperidine.

### Claim 6 (depends on 1)

The process of claim 1, wherein 1 to 20 moles of formic acid are present for each mole of the compound of formula III.

### Claim 7 (depends on 6)

The process of claim 6, wherein 3 to 6 moles of formic acid are present for each mole of the compound of formula III.

### Claim 8 (depends on 6)

The process of claim 6, wherein 0.1 to 1.0 mole of the amine is present for each mole of formic acid.

### Claim 9 (depends on 8)

The process of claim 8, wherein 0.1 to 0.5 mole of the amine is present for each mole of formic acid.