Green Process For Preparation Of 2,5-dimethyl-4-hydroxy-3(2H)-Furanone

2, 5-dimethyl-4-hydroxy-3(2H)-Furanone is a naturally safe flavor. It has been widely used in food, drink, tobacco, health care etc. Nowadays the demand of furanone is increasing. It is of great importance to develop a low-cost process for the preparation of furanone due to its significant position in Chinese flavor industry. According to literatures, some improvements are made in this paper.This paper is based on the previous work of our research group. With the aid of GC, GC-MS, NMR, IR etc, a systemic study is made on the preparation of furanone. A internal standard method was established to analyse methylglyoxa, dione and furanone simultaneouslly by GC in the reaction process. The optimized conditions are obtained as follows: a) At 20℃, methylglyoxal can be converted into dione with a yield of 46.09% after 2.5 hours;The ratio of threo dione to erythro dione is 2.2 to 1;b) At 70℃ , under pH6.47 , Dione, the intermediate, can be converted into furanone with a yield of 67.94% after 33 hours.Total yield of can reach up to 23%. It is a decent improvement compared with a yield of 13% reported in previous literatures. Meanwhile, a mixture of ethyl acetate/petroleum ether is used to replace ethyl ether in the extraction process of furanone. The underlying danger of using ethyl ether is eliminated. Furthermore, a process is proposed that ethyl acetate is firstly extracted by water from the mixture of petroleum ether and ethyl acetate, and then ethyl acetate is distilled from the mixture of ethyl acetate and water. Last but not least, NRTL equation is used to calculate the ternary liquid-liquid equilibrium. It is found that the experimental results are in fair agreement with the simulation results. A green design is also made for the whole process.