Study Of Acid Catalysis In Some Organic Synthesis Reaction

Xanthene derivatives constitute a structural unit in a number of natural products, and have been used as versatile synthons because of the inherent reactivity of the inbuilt pyran ring. Xanthene derivatives are an important class of compounds as they exhibit wide range of biological and pharmaceutical activities such as antiviral, hpyerglycemic, antianaphylaxis, antibacterial and antiinflammatory agents. Apart from these activities they are also used in photodynamic therapy, as well as dyes in laser technology and as pH sensitive ?uorescent materials for the visualization of biomolecular assemblies.Compounds bearing 1,3-amino oxygenated functional groups are ubiquitous to a variety of biologically important natural products and potent drugs including a number of nucleoside antibiotics and HIV protease inhibitors, such as ritonavir and lipinavir. In this research, we represent an advance in the context of synthetic methodology towards mentioned class of biologically important molecules. It is noteworthy that amidoalkyl naphthols can be converted to important biologically active amidoalkyl naphthols derivatives by amide hydrolysis reaction. The hypotensive and bradycardiac effects of these compounds have been evaluated.3,4-Dihydropyrimidin-2(1H)-(thio)one and its'derivatives have an extensive application in the realm of antimicrobes, antiviral, antitumor, anti-inflammatory, antibacterial and antimould due to their important therapeutic and pharmacological properties. They are usually used for synthesis of many peroral medicines, such as calcium channel blockers,α1a-antagonists and neuropeptide Y(NPY) antagonists, antihypertensive agents. Biginelli reaction is a significant path for synthesis of 3,4-Dihydropyrimidin-2(1H)-(thio)ones which have important pharmacological activities.This thesis consists of two major parts:The first part is about literature review. The progress in application and synthesis of Xanthene, 1-amidomethyl-2-naphthols and 3,4-Dihydropyrimidin-2(1H)-(thio)ones were systematic exposition.The second part is about experimental content:1 Xanthene derivatives were synthesized from the reaction of aromatic aldehyde with 5,5-dimethyl-1,3-cyclohexanedione in the presence of La(NO3)3 under solvent-free conditions.2 Amidoalkyl naphthols were synthesized from the reaction of aromatic aldehyde withβ-naphthol and acetamide or benzamide in the presence of graphite supported perchloric acid or polyphosphoric acid under solvent-free conditions.3 3,4-Dihydropyrimidin-2(1H)-(thio)ones were synthesized from the reaction of aromatic aldehyde with 1,3-dicarbonyl compounds and urea or thiourea employing La(NO3)3 as the catalyst by the Biginelli reaction.