Thiabendazole → 1-Benzylthiocarbonyl-2-(4-thiazolyl)-benzimidazole

Participants

Reaction Steps

17.0 G. (0.091 moles) of benzylthiocarbonyl chloride is added dropwise under anhydrous conditions over a period of 25 minutes to a stirred suspension of 18.3 g. (0.091 moles) of 2-(4-thiazolyl)-benzimidazole in 140 ml. of pyridine. All of the solid material dissolved before the completion of the addition. When the addition is complete, precipitation of pyridine hydrochloride commences. The reaction mixture is stirred at room temperature for 18 hours, filtered and the pyridine solution evaporated to dryness in vacuo. The residue is dissolved in 250 ml. of methylene chloride filtered and the filtrate washed twice with 250 ml. of 0.25 normal hydrochloric acid and 200 ml. of saturated sodium bicarbonate solution. The methylene chloride is dried, treated with charcoal, filtered and evaporated to dryness in vacuo affording a solid material which is recrystallized from toluene affording 14.3 g. (45%) of 1-benzylthiocarbonyl-2-(4-thiazolyl)-benzimidazole, melting point 122° to 123° C.

Provenance & Evidence