Kenneth F Barbour

US Patent:

44355688, Mar 6, 1984

Filed:

Jul 22, 1982

Appl. No.:

6/400756

Inventors:

Kenneth L. Barbour - Newark DE
William L. Geigle - New Castle DE
Frank R. Haglid - late of Wilmington DE

Assignee:

E. I. Du Pont de Nemours and Company - Wilmington DE

International Classification:

C07D25306

US Classification:

544182

Abstract:

The process of thiol methylation of butylthion using methyl bromide to produce metribuzin has been significantly improved by the development of a reaction temperature profile, the recycle of methylation process reaction supernatant, and new conditions for the regeneration of methyl bromide from used methylation process reaction supernatant.