https://www.selleckchem.com/products/Thiazovivin.html Aims & Objective An efficient procedure for the synthesis of pyrido[2,1-a]isoquinoline derivatives in excellent yields was investigated using catalyst-free multicomponent reaction of phthaladehyde, methylamine, activated acetylenic compounds, alkyl bromides and triphenylphosphine in water under ultrasonic irradiation at room temperature. In addition, Diels-Alder reactions of pyrido[2,1-a]isoquinoline derivatives with activated acetylenic compounds under ultrasonic irradiation are investigated in two procedures. The advantages of this procedure compared to report methods are short time of reaction, high yields of product, easy separation of product, clean mixture of reaction and green media for performing reaction. In addition, because of having isoquinoline core in synthesized compounds, in this research antioxidant activity of some synthesized compounds was studied. Materials and methods To a stirred mixture of phthalaldehyde 1 (2 mmol) and methylamine 2 (2 mmol) in water (3 mL) under ultrasonic irradiation ith activated acetylenic compounds and triphenylphosphine under ultrasonic irradiation is investigated in two procedures. Also, the antioxidant activities of 6a, 6c, 6g and 6i were evaluated by DPPH radical scavenging and ferric reducing power analyzes. The compounds 6a exhibit excellent DPPH radical scavenging activity and FRAP compared to synthetic antioxidants BHT and TBHQ. The chief benefits of our method are high atom economy, green reaction conditions, higher yield, shorter reaction times, and easy work-up, which are in good agreement with some principles of green chemistry.Background Several medicinal plants are being used in Indian medicine systems from ancient times. However, in most cases, the specific molecules or the active ingredients responsible for the medicinal or therapeutic properties are not yet known. Objective To report a computational protocol as well as a tool for generating novel poten