| 16-Dehydropregnenolone Acetate (simply signed as 1 6-DPA) is the most important intermediate in the synthesis of steroid hormones. It is used to manufacture various steroid drugs such as Cortisone acetate, Contraceptive, Androgens and Oestrogens. 1 6-DPA is prepared from the raw material diosgenin or solasodine. The synthesis method from solasodine has some disadvantages such as long reaction time, complicated treatment and low yield. While because of the source's limit for diosgenin west countries pay more attention to the research of this method. As to our country, diosgenin's content in the plants of the genus Dioscorea such as D. nzponica Makino, D. nz~ponica var Rosthornii Pr. Et Burk. is over 2% ,which can not only meet the domestic needs but also supply to the foreign countries. All of the factories in our country use the diosgenin as raw material .The product is synthesized after three steps'reaction which are acetolysis, oxidation and hydrolysis respectively. The 1 6-DPA has perfect market prospect with wide source and great price. From now, many corporations produce this product, while the average industrial yield is only 72%. For the low interest some corporations are up against closedown. How to improve the yield of 16- Dehydropregnenolone is becoming a big problem hurry to be resolved. Great economic benefit would be attained if the yield of 1 6-DPA were improved. The production cost would bring down 12-15 thousand yuan per ton if the yield is increased 1% .As far as a plant with the capacity of 100 tons is concerned, it means to add the economic benefits of 1.5 million yuan. For its significance, we made some studies on the synthesis of 1 6-DPA. By the inspection of references and choice of conditions, the HPLC quantitative analysis method is developed to analysis the intermediate product pseudodiosgenin diacetate and 1 6-DPA. The three-step synthesis course is divided into two parts, acetolysis and oxidation- hydrolysis, to research. The acetolysis reaction rule is mastered through a series of beforehand experiments and the kinetic model is built based on the reasonable simplification for the reaction course. The model parameters are determined by using of Matlab language .The verification indicated that the model can be used to predict the reaction course. The reaction processes under the same temperature and two different temperatures are simulated. Optimized conditions are obtained. The acetolysis yield is up to 91%. Relying on the method of sequential experiment factors such as material concentration, reaction temperature, oxidant ratio, reaction time are studied, the good conditions are confirmed. The effect of the reaction time to the hydrolysis yield is considered. By the curve of reaction the optimal hydrolysis time 75-90 minutes is obtained .The influence of temperature to hydrolysis is also discussed. Results show that high temperature is beneficial to the reaction. Under the optimal conditions, oxidation- hydrolysis's yield is up to 90-92%. The overall yield of synthesis is 82-83%, which is much higher than industrial average level 72% and 5-6% higher than the best industrial yield 76.7%.
|
PDF Full Text Request