Synthesis and characterization of “6-[2-hydroxy-3(substituted amino)propoxy]-2-Phenyl-4H-Chromen-4-one”

Polyphenolic compounds have recently attracted considerable interest in the field of nutrition, health and medicine. Our efforts are focused on the introduction of chemical diversity in the molecular frame work in order to synthesizing pharmacologically interesting compounds of widely different composition. Here we have reported the synthesis of flavonoid derivatives starting from commercially available material 6-hydroxyflavone based on beta-blocker and characterized by elemental analysis FTIR 8201using KBr pallet method, 1HNMR techniques. INTRODUCTION Flavonoids are a very large and important group of plant metabolites, present in all parts of plant, above and below ground, in vegetative and generative organs: stem, leaves, buds, bark, heartwood, thorns, roots, rhizomes, flowers, farina, fruits, seed, and also in root and leaf exudates or resin. In addition to various vegetables and fruits, flavonoids are found in nuts, grains, spices, and different medicinal plants as well as beverages, such as wine, tea, and beer. Flavonoids are responsible for the vividness in fruits and vegetables many have shown significant health beneficial activities in the prevention coronary heart diseases, bone loss, antioxidant, anti-microbial, antiinflammatory, vasculo-protective effects and other age-related diseases [1-6]. Some factors like their structural class, degree of hydroxylation, other substitutions, conjugations, and degree of polymerization are responsible for their chemical nature. The activities of flavonoids are structure dependent. Although some flavonoids are readily available from plants, more derivatives have been accessed through chemical synthesis [4, 5]. EXPERIMENTAL Material and Method The chemical used for the synthesis of products were purchased from sigma-aldrich and used without further purifations. Melting points were recorded by open capillary method and are uncorrected. Infrared spectra were recorded on Shimadzu FT IR-8201 using KBr pallet method. Spectra were calibrated against the polystyrene absorption at 1610 cm-1. Mass spectra were recorded on Shimadzu GC/MSQP 2000 spectrometer operating using direct injection probe technique. 1H NMR spectra were recorded on Bruker Avance 400 spectrometer by making a solution of sample in DMSO d6 and CDCl3 solvents using tetramethylsilane (TMS) as the internal standard unless otherwise mentioned and are given in the δ scale. Analytical thin layer chromatography (TLC) was performed on Merck precoated silica gel-G F254aluminium plated. Visualization of the spots on TLC plates was achieved either by exposure to iodine vapor or UV light. All evaporation of solvents was carried out under reduced pressure on Rota vapour. % yield reported are isolated yields of material judged homogeneous by TLC and before recrystallization. Elemental analysis was carried out on Elementar III Vario EL Carlo Erba 1108. Synthesis Compounds were synthesized following the procedure as shown in following scheme1: To a solution of 6hydroxyflavone (4a) (5g, 21mmol) in DMF (60 ml), potassium carbonate (8.6g, 63mmol) was added, and solution was stirred for 10 min. Then epichlorohydrin (3.8 g, 42mmol) was added and the mixture was stirred at 80 °C for 7h and give product 4b. schem 2: Isopropylamine (5 eq) was added to a solution of 4b in ethanol and stirred at 70°C for 7h and give 6-[2-hydroxy-3(substituted amino)propoxy]-2-phenyl-4H-chromen-4-one as a product (4c). After the completion of reaction in each step as monitored by the TLC, it was then extracted with ethyl acetate and washed with water, brine solution and dried over anhydrous Na2SO4. The combined organic layer was concentrated under reduced pressure to give the product in good yield which was pure enough to use as such for the next step. Similarly, we have carried this reaction for different kind of amines to give good result.