چكيده به لاتين
Green and simple methods have been developed for the efficiency preparation of biscoumarin derivativesin the presence of low loading of Periodic mesoporous organosilicas (PMOs) nano catalyst. This procedure is a clean, transition metal-free, and environmentally friendly approach that offers many advantages including short reaction time, high to quantitative yields, low cost, and straightforward work-up. The advantages of this catalyst is easy separation from reaction mixture, recyclability and considerable stability in organic solvent.
Biscoumarin is one of the most important heterocyclic compounds.In this project, Periodic mesoporous organosilicas (PMOs) nano catalyst as environmentally friendly heterogeneous catalyst have been used for synthesis of biscoumarin derivatives by the multicomponent reaction of aldehyde and 4-hydroxycumarin under reflux in water as a green solvent. The advantages of this method are short reaction time, higher yield of products, the use of safe solvent and mild and recyclable catalyst.
Furthermore, in this work we used the processed seashells with ball milling as a green and heterogenous nanobiocomposite catalyst in preparation of aspirin and obtained considerable results. High abundance of seashells in nature, no needing for complex processing steps, recoverability, high efficiency and environmentally friendly is some of outstanding features of this nanobiocomposite.
Aspirin or acetylsalicylic acid (ASA) is a prototype of non-ster-oidal anti-inflammatory drugs (NSAIDs), and one of the most widely used medications in general medical practice. Higher doses are analgesic, antipyretic and anti-inflammatory,¬ while lower doses are employed for the prevention of cardiovascular thrombotic events. Utilize of the features of this nanobiocomposite as a heterogeneous catalyst in the preparation of this medicine can be very valuable. For the characterization of the nanocomposite, various methods such as, SEM, XRD, FT-IR, DTA and TG have been used.
