Study On The Process For Synthesis Of Hydroquinone With Benzoquinone

Hydroquinone is an important basic organic raw material, which is widely used in thefield of chemistry industry, such as rubber, pharmaceuticals, dyes, and pesticides. In recentyears, the application field of hydroquinone has been constantly widening. At present, newuses have been found in fertilizer industry in domestic. There are many traditionalsynthesis methods of hydroquinone, which are Reppe, aniline oxidation, bisphenol A, andphenol hydroxylation. However, there are some disadvantages in these methods, which arelow yield, lots of waste, low utilization ratio of raw material, and much environmentalpollution. Therefore, it is great significance to study the new technology of synthesismethods of hydroquinone.Two methods were used to optimize the synthesis route of hydroquinone:(1)Chemical reduction method. In this method, the effects to the yield of hydroquinone wereinvestigated, which were the choice of reductant, ratio of raw materials, reaction time,solvent dosage, water dosage, and the times of application of mother liquor aftercrystallization. The results show that at room temperature, when ammonium sulfite is takenas reductant, the ratio of m (benzoquinone)/m (ammonium sulfite) is1/2.5, reaction time is30minutes, solvent dosage is250mL, water dosage is150mL, and the times of applicationof mother liquor after crystallization is1, the yield of hydroquinone can be reached to75.48%, the purity of hydroquinone is over98%, and it is white and needle-like crystal.(2)Catalytic hydrogenation method. In this method, the effects to the yield of hydroquinonewere investigated, which were the choice of catalyst, catalyst dosage, reaction time,reaction temperature, reaction and pressure. The results show that when Pd/C is taken ascatalyst, reaction temperature is45℃, catalyst dosage is0.4g, reaction time is4h, and thereaction pressure is0.4MPa, the yield of hydroquinone can be reached to90.54%, thepurity of hydroquinone is over98%.At last, the suitable synthetic technologies were obtained by comparing thedifferences of new and traditional technology. At the same time, the structure of productwas characterized by melting point analysis, IR, and1H-NMR characterization methods.