Antiparasitic agents. 5. Synthesis and anthelmintic activities of novel 2-heteroaromatic-substituted isothiocyanatobenzoxazoles and -benzothiazoles

Abstract

The synthesis and antiparasitic properties of 22 isothiocyanato-2-pyridinylbenzoxazoles and benzothiazoles are described; the preparation and anthelmintic activities of 14 isothiocyanato-2-thienyl-, -furyl-, and -pyrrolylbenzoxazoles are outlined. In mice experimentally infected with Nematospiroides dubius (nematode) and Hymenolepis nana (tapeworm), three derivatives, i.e., 5-isothiocyanato-2-(2-furyl)benzoxazole (34), 5-isothiocyanato-2-(5-methyl-2-furyl)benzoxazole (35), and 5-isothiocyanato-2-(1-methyl-1H-2-pyrroly)benzoxazole (37), show 100% nematocidal activity and two, i.e., 5- and 6-isothiocyanato-2-(3-pyridinyl)benzoxazole (5) and 5- and 6-isothiocyanato-2-(3-pyridinyl)benzthiazole (21), show 10% taeniacidal activity at 0.2% in the diet. Two derivatives (5 and 21) show good nematocidal activity in sheep. Maximum activity requires 3-pyridinyl derivatives for both the benzoxazole and benzothiazole series.

Protein Engineering of the Archetypal Nitroarene Dioxygenase of Ralstonia sp. Strain U2 for Activity on Aminonitrotoluenes and Dinitrotoluenes through Alpha-Subunit Residues Leucine 225, Phenylalanine 350, and Glycine 407

“…For example, 24DNBA has been evaluated as a precursor for carbamates used in the synthesis of tumor treatments (3) and antibiotic prodrugs (9); hence, the 23DNBA product synthesized as described in this report from 23DNT, which is not commercially available, may be useful as a precursor. In addition, isomers of 4-amino-2-nitrocresol (generated here from the oxidation of 4A2NT) such as 6-amino-4-nitro-o-cresol and 2-amino-5-nitrop-cresol have been evaluated as a precursors for fungicides (42) and antiparasitic agents (8), respectively.…”

An Update on the Synthesis of Benzoxazoles

“…2-Methylbenzoxazole (31) reacts with benzaldehyde in the presence of zinc chloride to give the 2-benzylidene derivative (41) indicating the reactivity of the methyl group linked to azomethine system. (42) is reactive enough to couple with diazonium salts and reacts at the 2-methylene group with aldehydes, nitroso compounds, and amyl nitrite.…”

The Quantitative Structure-Activity Relationships of Antifungal Active 2- (p-Substituted-Phenyl) Benzoxazole Derivatives Against Candida Albicans Using The Combinations of Some Hydrophobic, Electronic

“…Benzoxazoles substituted at G-2 were prominently studied (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) trusting that this position is decisive for the biological activity. Evans et al showed that para substituted 2-aryl-5-benzoxazolealkanoic acid derivatives had the highest activity compared to its analogs (12,13).…”