Melvin John Guillory

US Patent:

42529654, Feb 24, 1981

Filed:

Jul 5, 1979

Appl. No.:

6/055115

Inventors:

Henry C. Grace - Baton Rouge LA
Melvin J. Guillory - Baton Rouge LA

Assignee:

Ciba-Geigy Corporation - Ardsley NY

International Classification:

C07D24912

US Classification:

548263

Abstract:

An improved process is provided for the production of 1-substituted-3-hydroxy-5-chloro-1,2,4-triazoles which involves reacting in dilute solution a 1-substituted-1-cyanohydrazine with phosgene in tetrahydrofuran as the specific inert solvent, treating the reaction mixture with anhydrous ammonia to form an ammonium salt of the 1,2,4-triazole, said ammonium salt being insoluble in tetrahydrofuran, and liberating from said isolated salt the 1,2,4-triazole in yields from about 85 to 92% of theory and in very pure state by treating said salt with an acid. The 1,2,4-triazoles are valuable intermediates in the manufacture of pesticides.

US Patent:

42551676, Mar 10, 1981

Filed:

Nov 17, 1978

Appl. No.:

5/961794

Inventors:

Robert M. Babb - Baton Rouge LA
Melvin J. Guillory - Baton Rouge LA

Assignee:

Ciba-Geigy Corporation - Ardsley NY

International Classification:

B01D 5314

US Classification:

55 71

Abstract:

A single-step process is disclosed for purifying raw cyanogen chloride gas contaminated with chlorine by fractionally separating chlorine from cyanogen chloride and thereafter absorbing essentially chlorine-free cyanogen chloride in a solvent.