Synthesis and Biological Evaluation of Some New Chalcone Derivatives For their Antimicrobial Activities

In step-I, A solution of benzaldehyde (12 gm, 11.7 ml, 0.1 mol.) in methanol was mixed with acetophenone (10.60 gm, 10.2 ml, 0.1 mol.) and an aqueous solution of potassium hydroxide (60%) was added to it till, further no turbidity occurs. The reaction mixture was stirred for 20 hrs and kept overnight at room temperature and then it was poured into crushed ice and acidified with dilute hydrochloric acid. In step-II, A mixture of 4-bromophenyl semicarbazide (2.3 gm, 0.01 mol) and chalcone (2.08gm, 0.01 mol.) in methanol was stirred at 60–70°C for five hours in the presence of 23 ml of conc. hydrochloric acid. The reaction mixture was poured into a beaker containing crushed ice and allowed to stand for two hours. The precipitate so formed was filtered and washed with ice cold water followed by ice cold methanol.