Process for preparing thiabendazole
AssigneeE. I. Du Pont de Nemours and Company
InventorsPatti A. Parziale, Tzu-Ching Chang, Lynn E. Applegate
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Abstract
Process for preparing 2-(4-thiazolyl)-1H-benzimidazole (generic name: thiabendazole) by the acid-catalyzed condensation of o-phenyldiamine and 4-cyanothiazole in solution in water or mixtures of water with miscible co-solvents (solvents which upon mixing with water in all proportions form a homogeneous mixture, as well as, other partially miscible solvents which upon mixing with water in some proportions form a homogeneous mixture under the reaction conditions of the process of this invention).
Claims10
A process for preparing thiabendazole which comprises reacting 4-cyanothiazole with (a) o-phenylenediamine in the presence of an acid catalyst, or (b) a protonic acid salt of o-phenylenediamine, at a temperature in the range between 80.degree. and 145.degree. C. and a pH of from 2.5 to 6.0 in solution in water, or in solution in mixtures of water with miscible co-solvents, for a time sufficient to effect the desired conversion to thiabendazole, and recovering thiabendazole from the reaction mass.
A process for preparing thiabendazole which comprises reacting o-phenylenediamine and 4-cyanothiazole at elevated temperatures in the presence of water or mixtures of water with miscible co-solvents and sufficient hydrochloric acid to maintain a pH of from approximately 2.5 to approximately 6.0, for a time sufficient to effect the desired conversion to thiabendazole, and recovering thiabendazole from the reaction mixture.
Dependencies are inferred from the claim text.