Back to results
US 5,344,977 AGranted
Process for the preparation of 2,3-dibromopropionyl chloride
AssigneeCiba-Geigy Corporation
InventorsAlfons Arquint, Peter Leupin
Life of this patent
Estimating the term…
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.
Claims3
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.
1 more element
Dependencies are inferred from the claim text.