Study Of The Synthesis Technology Of Provitamin D₃

Vitamin D₃ is a fat soluble vitamin,it's essential for human and animal of growth,development,reproduction,sustain life and keep healthy.It can be used for clinically treatments of rickets,osteoporosis and hypothyroidism psychosis.The synthesis of Provitamin D₃?key intermediate?is the difficulty and key point in the whole production process of Vitamin D3,and this technology has been monopoly by foreign companies,however,the existing technology still have problems like high cost,more wastes and low purity of products etc.In summary,developing a new and environmental-friendly synthesis technology of provitamin D₃ will improve the vitamin D3 industry development in our country.This article have three chapters,firstly we summarized the pharmacological activities and synthetic routes of Vitamin D₃ in Chapter1.Secondly in chapter 3,we introduce the process optimization of synthetic technology of N-Hydroxyphthalimide?NHPI?which is the catalyst in oxidation of cholesterol-3-acetate,and six derivatives of NHPI was developed by this new technology.Finally,in Chapter 3,we introduce the design and synthetic route of provitaminD₃ from the starting material of Cholesterol.First,the cholesterol is protected by hydroxyl and with oxidation of allylic position air to getting acyl-cholesterol-7-ketone,this chemical compound was condensed with tosyl hydrazide to produce hydrazine,and synthesis of provitamin D₃ with Bamford-Stevens reaction,the double bond will not move during the process of remove hydrazine,and the product purity improved significantly.We have compared with the traditional way of put bromine and remove bromide,our technology have many advantages such as cheap reagent,mild reaction,low cost,simple post-processing and have obvious industrialization value.