Method for preparation 3-(hydroxyphenylphosphinyl)-propanoic acid
US6090976A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1999 |
| Grant date | Jul 18, 2000 |
| Priority date | — |
| Expiry date | Oct 12, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07F9/301
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Disclosed is a method for the preparation of 3-(hydroxyphenylphosphinyl)-propanoic acid which is commonly used as a flame retardant for polyester resins. The preparation of 3-(hydroxyphenylphosphinyl)-propanoic acid is attained by the condensation of phenylphosphonous dichloride and acrylic acid and the hydrolysis of the condensate. In the condensation, the mole ratio of phenylphosphonous dichloride to acrylic acid is within the range of 1:1.1 to 1:1.25. Under a pressure of greater than 1 atm, acrylic acid is added at 65.about.110.degree.C. at an amount more by 10.about.25 mole % than that of phenylphosphonous dichloride and the condensation is carried out at a temperature of 70.about.100.degree. C. under at greater than 1 atm, to produce 3-(hydroxyphenylphosphinyl)-propanoic acid at high yields with desired color.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.