Study On Process For Preparing 1, 4-Dioxan-2-One

1, 4-dioxan-2-one is a kind of important organic chemical intermediate and material, which can be used widely in the field of biodegradable materials, medicine and other fine chemicals industry.This text relates to two different technicses to synthesis of 1, 4-dioxan-2-one .In the first technics, ethylene glycol was used as starting material to synthesize of monosodium salt of ethylene glycol and sodiumβ-hdroxyethoxy acetate. The object product was synthesized by esterification using sodiumβ-hdroxyethoxy acetate as starting material. The synthetic effects on the reaction were investigated such as amount of ethylene glycol and reaction time in the frontal two process; reaction temperature, reaction time and amount of acid in esterification process; solvent retrieve. The optimal synthetic technology was as follows: synthesize of monosodium salt of ethylene glycol at 130℃for 12h with the mole ratio of ethylene glycol to sodium hydroxide being 3.6: 1; condensation reaction using 1 equiv. ethylene glycol and 1 equiv. of sodiummonochloroacetate at 80℃for 3h; esterification at 30℃for 1h with the mass ratio of acid H₂SO₄ to sodiumβ-hdroxyethoxy acetate being 25.8%, the total yield of object product was 57.7% based on the sodium hydroxide. In the second technics, the object product was synthesized by the dehydrogenation of diethylene glycol with copper chromite as catalyst. The synthetic effects on the reaction were investigated such as height of dephlegmator, kind of catalyst, amount of catalyst and solvent reclaim in the process. The optimal synthetic technology was as follows: dehydrogenation at 220～280℃for 3h with the mass ratio of catalyst copper chromite to diethylene glycol being 3: 50 by the dephlegmator which was 12cm heigh; the copper chromite containing 39% chromium was the preferred catalyst. The total yield of object product was 80% based on diethylene glycol.The evaluation of advantage to the both technology was got through the calculation of material balance to provide a basis for industrial production. The first technics has been applied to produce 1, 4-dioxan-2-one in industry.