SYNTHESIS OF BENZO[1,2-b: 5,4-b′]- DIFURANYL-TRIAZOLES, -OXADIAZOLES, -THIAZOLIDINONES, -THIADIAZOLES, AND THE USE OF DNA IN EVALUATION OF THEIR BIOLOGICAL ACTIVITY

Abstract

Benzo[1,2-b:5,4-b′]difuran-2-carbohydrazides 5a, b were reacted with aryl or alkyl isothiocyanates to give the corresponding thiosemicarbazides 6a–h. Cyclization of the substituted thiosemicarbazides with sodium hydroxide led to the formation of benzo[1,2-b:5,4-b′]difuranyl-1,3,4-triazoles 7a–f. Desulfurization of thiosemicarbazides by mercuric oxide gave benzo[1,2-b:5,4-b′]difuranyl-1,3,4-oxadiazoles 8a–f. Treatment of thiosemicarbazides with ethyl bromoacetate or α-bromopropionic acid yielded benzo[1,2-b:5,4-b′]difuranyl-carbonyl-hydrazono-4-thiazolidinones 9a–f and 10a–f, respectively. Furthermore, the reaction of the thiosemicarbazides with phosphorus oxychloride gave benzo[1,2-b:5,4-b′]difuranyl-1,3,4-thiadiazoles 11a–f. Some compounds in this study were biologically evaluated for their ability to bind to DNA.

Keywords:

• Benzodifuran
• oxadiazole
• thiazole
• thiadiazole
• triazole

Notes

^∗Values represent the concentration (mean ± SD, n = 3 to separate determinations) required for 50% decrease in the initial absorpance of the DNA methyl green solution.