Patent number: 4346248
Abstract: A process for the preparation of 2,4,5-trichlorophenol and 2,4,5-trichlorophenoxyacetic acid free of 2,3,7,8-tetrachloro-dibenzo-p-dioxin contamination by the steps of nitrating 1,2,4-trichlorobenzene, reducing the resulting 1,2,4-trichloro-5-nitrobenzene, diazotizing the resulting 2,4,5-trichloroaniline, hydrolyzing the resulting 2,4,5-trichlorobenzenediazonium salt and recovering 2,4,5-trichlorophenol. The 2,4,5-trichlorophenol is reacted with monochloroacetic acid to give 2,4,5-trichlorophenoxyacetic acid. Both the 2,4,5-trichlorophenol and the 2,4,5-trichlorophenoxyacetic acid produced by the process are analytically free of 2,3,7,8-tetrachloro-dibenzo-p-dioxin in analytical tests sensitive to 1 part per billion.
Type:
Grant
Filed:
May 22, 1981
Date of Patent:
August 24, 1982
Assignee:
Vertac Chemical Corporation
Inventors:
Dennis L. Deavenport, Kenneth J. Howard, Albert E. Sidwell