Study On The New Preparation Process Of 16-dehydropregnenolone Acetate

16-DehydroPregnenolone Acetate(simply signed as 16-DPA)is the most important intermediate in the synthesis of steroid hormones.16-DPA is used to synthesize about 70% of the steroid hormone drugs.At present,most of the factories in our country use the diosgenin as material.The product is synthesized after three steps' reaction which are acetolysis,oxidation and hydrolysis respectively.Its production process to use a large amount of chromic anhydride,so that the waste contains large amounts of chromium ions,causing serious pollution to the environment.This study accordance with the idea of green chemistry,hoping to use clean oxidant in place of chromium anhydride.By the inspection of relevant references,selecting hydrogen peroxide as the oxidant,tungsten-containing compound as a catalyst,by oxidation and hydrolysis reaction to synthesize 16-DPA.First,the use of acetolysis reaction solution plant as raw material,adding different loadings of phosphotungstic acid and silicotungstic acid as catalyst,hydrogen peroxide as the oxidant to achieve the oxidation reaction.During the experiment,the design of single factor experiment and relying on the method of experiment factors such as different amounts of catalyst loading,catalyst amount,the amount of oxidant and reaction temperature are studied,the good conditions are confirmed.We conducted experiments in accordance with the selected experimental conditions,and the overall yield of synthesis is 38%.Then,using diosgenin as raw materials,by atmospheric acetolysis reaction and column isolated to get pure acetolysis production,this step is only considered the amount of ammonium chloride influence on the reaction,the yield of the open loop can reach 85%.Then useing pure acetolysis product as raw material for the oxidation reaction,and using the same catalyst,single factor experiment of reaction temperature,catalyst,catalyst amount and the amount of oxidant on the reaction.by LC-MS found the oxidation step conversion rate to more than 70%,and the highest yield of oxidation and hydrolysis reaction is 52%.In front of the acetolysis reaction combined total yield up to 43%.Finally,using diosgenin as the raw material,oxalic acid,salicylic acid,amino acid and other compounds containing bidentate N/O as a ligand,sodium tungstate and hydrogen peroxide as oxidation liquid composition.Then oxidatized acetolysis liquid,hydrolyzed to get 16-DPA.Single factor experiments mainly on the organic ligand,affecting the amount of catalyst,reaction temperature and reaction time are studied,the good conditions are confirmed.Under the optimal conditions,the yield is about 28%.The experimental results were analyzed and the results showed that the results are good,yield can reach 43% when the pyrolysis products are purified before participating in the next oxidation reaction.Meanwhile,the final experimental is not reached pilot stage,but the resulting data has a certain reference value.Vigorously promoting green chemistry today,the production process will continue to optimize various data obtained in the present study,the production process has made a useful exploration.