Study On Synthesis Process And Reaction Characteristic Of Novel Heterocyclic Perfumes—quinoxaline Derivatives

Pyrazine and its derivatives as a class of heterocyclin compounds has a unique aroma characteristics,reliable food and commercial value. Mainly as flavors and fragrances used in food and daily chemicals industry,it also can be used as pharmaceutical intermediates for drug synthesis. Quinoxa-line and its derivatives as an important chemical intermediate get a wide range of applications in the field of medicine,pesticide,feed,flavors and fragrances, fungicides, insecticides, herbicides, plant growth regulators, fluorescent probes and dyes intermediates, etc. Quinoxaline nitrogen-oxy-gen compounds with physiological activity of the compounds as an antit-umor sensitizers with the use of radiotherapy with chemotherapy, can sig-nificantly improve the cure rate of the tumor,medicine used as a new type of anticancer drug research,and entered the clinical phase.This paper biefly describes the pyrazine derivatives and quinoxalines applied research and progress, and summarizes the current literature reports of various pyrazine derivatives and quinoxaline derivatives. On this basis, focused on the improvement of synthetic methods and reaction rules of5,7,7-trimethyl-5,6,7,8-tetrahydroquinoline;2,6,6,8-tetramethyl-5,6,7,8-tetrahydroquinoline and2,5,7,7-tetramethyl-5,6,7,8-tetrahydroqu-inoline,and obtaine satisfactory results.The series of substances synthesis in liquid-phase of one-step,with a two-step reaction system by condensation and dehydrogenation. In experiments,we use3,5,5-trimethyl-1,2-cyclohexanedione,ethylenediami-ne and1,3-propanediamine as raw materials, ethanol as solvent, focused on the synthesis of the reaction conditions and reaction laws of 5,7,7-trimethyl-5,6,7,8-tetrahydroquinoline;2,6,6,8-tetramethyl-5,6,7,8-te trahydroquinoline and2,5,7,7-tetramethyl-5,6,7,8-tetrahydroquinoline. Examined the dehydrogenating agent of composition and dosage on synthesis yield.The experiment determine the synthesis of the series of tetrahydroquin-oxaline optimum reaction conditions,and the amount of dehydrogenat agent and composition ratio:the condensation temperature of25～30℃,dehydrogenation reaction conditions:ethanol refiux8h,yield to90%.And discussed the research and development trenf, market prospects and significance of5,7,7-trimethyl-5,6,7,8-tetrahydroquinoline;2,6,6,8-tetramethyl-5,6,7,8-tetrahydroquinoline and2,5,7,7-tetramethyl-5,6,7,8-tetrahydroquinoline.