A facile ultrasonic synthesis approach to 3-H-quinazolinethione derivatives and their urease inhibition studies

In this study, a new series of 3H-quinazoline-4-thione derivatives were synthesized under ultrasonic irradiation conditions with high yield in a short time. The new compounds were characterized by FT-IR,¹H, and ¹³C NMR spectral data. The antiurease activities of all new compounds were tested according to the method by Weatherburn. The inhibition results with the 3H-quinazoline-4-thione ring compounds were compared with those of some previously synthesized 3H-quinazolin-4-ones. More effective results were found for most quinazolinethione compounds. All new synthesized compounds have effective urease inhibition activity. Especially, the compound 2-(4-nitrobenzyl)quinazoline-4(3H)-thione (2i) has the best inhibition results with IC₅₀ = 1.6 ± 0.049 μg/mL.