3-(N',N'-Dialkylthioureido)quinazolin-4( prepared by the reaction of 3-aminoquinazolin-4(3H)-one with thiuram disulfides undergo the previously unknown acid-induced recyclization to give the corresponding 5-(2-aminophenyl)-2-dialkylamino-1,3,4-thiadiazoles. The structures of the products obtained were confirmed by IR and H-1 and C-13 NMR data. A plausible mechanism of the recyclization is discussed.
3-(N',N'-Dialkylthioureido)quinazolin-4( prepared by the reaction of 3-aminoquinazolin-4(3H)-one with thiuram disulfides undergo the previously unknown acid-induced recyclization to give the corresponding 5-(2-aminophenyl)-2-dialkylamino-1,3,4-thiadiazoles. The structures of the products obtained were confirmed by IR and H-1 and C-13 NMR data. A plausible mechanism of the recyclization is discussed.
3-(N',N',S-trialkyl isothioureido)quinazolin-4(3 H)-ones obtained by the reactions of 3-(N',N'-dialkylthioureido)quinazolin-4(3H)-ones with alkyl halides undergo unusual recyclization into 5-(2-aminophenyl)-2-dialkylamino-1,3,4-oxadiazoles under the action of aqueous solutions of alkali, hydrazine, and primary aliphatic amines. A plausible mechanism of the recyclization was proposed.