Abstract
Syntheses of 2-[2-(5-nitro-2-furyl) vinyl]-5-ethoxy (or chloro)-1, 3, 4-oxadiazole (III or V) and 4-substituted 2-[2-(5-nitro-2-furyl) vinyl]-1, 3, 4-oxadiazolin-5-ones are described. When 1-[3-(5-nitro-2-furyl) acryloyl]-2-ethoxycarbonylhydrazine (II) was refluxed with excess phosphoryl chloride, it gave III and 2-[2-(5-nitro-2-furyl) vinyl]-1, 3, 4-oxadiazolin-5-one (IV). However, when equivalent amount of phosphorus pentachloride was employed instead of phosphoryl chloride in this reaction, the main product was V. IV and 2-(5-nitro-2-furyl)-1, 3, 4-oxadiazolin-5-one (VI), when refluxed with equivalent amount phosphorus pentachloride, gave V and 2-(5-nitro-2-furyl)-5-chloro-1, 3, 4-oxadiazole (VII), respectively. 4-Substituted 2-[2-(5-nitro-2-furyl) vinyl]-1, 3, 4-oxadiazolin-5-ones (VIIIa∼i, IXa∼c) were prepared by acylation and disubstituted aminomethylation of IV and the products are shown in Tables II and III. Other oxadiazoline derivatives, 4-pyrimidinyl-2-[2-(5-nitro-2-furyl) vinyl]-1, 3, 4-oxadiazolin-5-ones (XIa, b) were obtained by the action of phosgene on the dioxane solutions of 1-[3-(5-nitro-2-furyl) acryloyl]-2-pyrimidinylhydrazines (Xa, b). Most of these nitrofuran compounds were found to be active against Escherichia coli NIHJ, Staphylococcus aureus FDA 209 P, and Trichomonas vaginalis 4 FM.
