# US 5,344,977 A · Process for the preparation of 2,3-dibromopropionyl chloride

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- Number: US 5,344,977 A
- Document ID: US5344977A
- Status: Granted
- Kind: A
- Application number: 08/008,056
- Filed: 1993-01-22
- Granted: 1994-09-06
- Earliest claimed: 1990-05-17
- Assignees: Ciba-Geigy Corporation
- Inventors: Alfons Arquint; Peter Leupin
- Web page: https://patentgrep.com/patent/US5344977A

## CPC

- C07C 51/363: by introduction of halogen; by substitution of halogen atoms by other halogen atoms
- C07C 51/60: by conversion of carboxylic acids or their anhydrides {or esters, lactones, salts} into halides with the same carboxylic acid part
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

An improved process for the preparation of 2,3-dibromopropionyl chloride, which comprises brominating acrylic acid, adding iron powder or an iron salt to the resultant melt, chlorinating the dibromopropionic acid obtained, and removing the volatile components. The 2,3-dibromopropionyl chloride is obtained in high yield and purity and is an intermediate for synthesising in particular reactive dyes.

## Claims

### Claim 1

A process for the preparation of 2,3-dibromopropionyl chloride, in one reactor without isolation of intermediate compounds, which consists essentially of the following sequence of steps:
a) brominating acrylic acid with liquid bromine in the temperature range from 20.degree. to 70.degree. C.,
b) adding iron powder or an iron salt selected from the group consisting of iron(III) chloride, iron(II) chloride, iron(II) iodide, iron(II) nitrate, iron(III) bromide, iron(II) oxide, iron(III) oxide, iron(II) hydroxide, iron(III) hydroxide and iron(II) sulfate to the resultant melt,
c) chlorinating the dibromopropionic acid obtained to 2,3-dibromopropionyl chloride by adding 5 to 25% excess thionyl chloride thereto uniformly over a period of 3 to 10 hours in the temperature range from 55.degree. to 75.degree. C., substantially in the absence of a solvent, and
d) removing the volatile components.

### Claim 2 (depends on 1)

A process according to claim 1, wherein the iron salt in step b) is iron(III) chloride.

### Claim 3 (depends on 1)

A process according to claim 1, wherein 0.01 to 2.0 mol % of iron powder or an iron salt is added in step b), based on the acrylic acid.