Acridone Ketoneses Green Synthesis Process Research

Quinacridone and its derivatives, as a kind of representative high-grade organic pigments,with excellent performance, have been widely used in metallic inks, engineering plastics,building materials and other fields. Our country has rich resources of raw materials, but majordomestic manufacturing enterprises of quinacridone pigments exist high cost, large energyconsumption, serious environmental polluting and other phenomenon, meantime developmentand production products have big gap compared with foreign countries. Therefore, depth study oftheir synthesis craft, still has important practical significance and industrial value.In this paper, first using succinate and methanol obtained dimethyl succinate throughesterification reaction, and conducted characterization its concentration by gas chromatography.Orthogonal test studied raw material ratio, catalyst amount, reaction temperature, reaction timeinfluence on the esterification reaction, and got the best synthesis craft: raw materials molar ration(methanol): n(succinate) was4.5:1, catalyst amount was25g/mol (succinate), reactiontemperature was80℃, reaction time was7h.Then using homemade dimethyl succinate and sodium methoxide through intermolecularClaisen, Dieckmann intramolecular condensation reaction and sulfuric acid acidification, gotdimethyl succinylsuccinate, and conducted characterization its structure using melting point,infrared spectroscopy, liquid chromatography. Single-factor experiment studied the influence ondimethyl succinylsuccinate purity and yield, through the amount of raw materials, sodiummethoxede, reaction temperature and acidefication sulfuric acid mass fraction, and gotpreliminary process parameters. Then used orthogonal test to optimize, and got the best synthesisprocess: raw materials molar ratio n(dimethyl succinate): n(sodium methoxide) was4.4:1,sodium methoxide dropping time was105min, reaction temperature was110~120℃,acidification sulfuric acid mass fraction was35%.Experiment adopted self-made dimethyl succinylsuccinate and P-toluidine, throughcondensation reaction, got2,5-P-dimethyl aniline-3,6-dihydro-dimethyl terephthalate, and withpolyphosphoric acid Closed-loop response got2,9-dimethyl-6,13-dihydro quinacridone, and thenwith oxidant hydrogen peroxide through oxidation reaction, got PR122Crude, after pigmentprocessing got pigment Red PR122(2,9–dimethyl-quinacridone). And conducted characterizationtheir structure using infrared spectroscopy, UV absorption spectroscopy, and1H NMR.Single-factor experiment studied the condensation reaction, the closed-loop response andoxidation process raw materials ratio, reaction temperature and reaction time on reactioninfluence, got PR122the best synthesis process conditions in condensation reaction, the closed-loop response and oxidation: raw materials ratios were2.5:1,3:1,1.3:1, the reactiontemperature were100℃,120~125℃,135~140℃, reaction time were6h,4h,3h.In summary, this article provides a new idea synthesis quinacridone new craft of greensynthesis new type organic pigments research, by molecular design and substituents modification,has obvious theoretical significance and application value.