The Isolation Of FK520 And Its Synthesis Of Derivatives

Immunosuppressant drugs, also called anti-rejection drugs, are a kind of drug which have immunosuppressive effects. Mainly used to treat the autoimmune diseases and to prevent organ transplant rejection in clinic. The study on immunosuppressive agents abroad, after the success of the first human case between twins with the egg of kidney transplant since 1954, doctors in the study of organ transplant have made a number of major breakthroughs. Since the early 1980s, cyclosporine A (CsA) are used in clinic, organ transplant has made tremendous achievements, FK506 and MMF have been certified by the United States FDA and listed. Immunosuppressants in organ transplant play an increasingly important role; In addition to being used to prevent organ rejection, immunosuppressant drugs are also used to treat such severe skin disorders as psoriasis and such other diseases as rheumatoid arthritis, Crohn's disease (chronic inflammation of the digestive tract) and patchy hair loss (alopecia areata). Some of these conditions are termed "autoimmune" diseases. With the mastering and understanding of the theory of transplantation immunology and molecular biology technology, People discovered and developed many new drugs, some of which have entered clinical trials and evaluation phase. In recent years, domestic scholars are also actively engaged in the research and development of immunosuppressant. However, due to a late start, and the high cost of research and development, at present, only a handful of domestic companies involved, mainly in generic drug abroad.Pimecrolimus [commodity name] Elidel, a new generation of immunosuppressant drugs developed by Novartis company, and in 2002 the first listing in the United Kingdom. mainly used as immunosuppressive drugs and the treatment of atopic dermatitis, as an antipsoriasis drugs and the treatment of asthma drugs have entered Phase II clinical trial stage, as an anti-arthritis drug and treatment of G1 inflammatory drugs will soon enter clinical trials. Pimecrolimus is a derivative of antibacterials ascomycin (FK520) which belongs to macrolide antibiotic drug, Domestic manufacturers are not yet available, Therefore, the study of the drug synthesis method for the development of new drugs have some value.Objective1 Isolation and Purification of the FK506 and FK520 from the end of the FK506, FK506 and FK520 are pure materials.2 Using FK520 as a raw material, established the preparation methods of pimecrolimus, optimized synthesis process.3 The HPLC determination of pimecrolimus was researched, made initial research on isomer.Methods1 Established a method for isolation of FK520 and FK506, firstly purified the mixed solution of FK520 and FK506, removed the oily mixture of substances and other impurities and then obtained pure FK520 and FK506 using silver nitrate silica gel column chromatography .2 Using FK520 as a raw material, prepared the target product pimecrolimus.2.1①The intermediate I was prepared from FK520 by using TBDMS Trifluoromethanesulfonate to protect the C-24 and C-33 hydroxyl.②Under the conditions of the p-toluenesulfonate, I deprotection of the C-33 base, generated II;③II in DMAP catalytic conditions, the o-nitrophenyl activated chloride generated III;④Using chloride lithium as chloride agent, III generated IV;⑤IV in HF acid conditions, deprotection of the C-24 base, obtained the final product V. In addition, II can be Chlorided directly without using activating agent, generated IV.2.2 According to the latest literature, we found C-24 hydroxy group of FK520 lower activity and it can be conducted without special protection, we have adopted triphenylphosphine-BTC as chlorine agent, triphenylphosphine-NCS as chlorine agent and triphenylphosphine-carbon tetrachloride as chlorine agent, and achieved the desired results. We also made some reasonable improvement to simplify the working steps, to save the cost and to reduce pollution.Results1 Successfully separated and obtained the pure FK520 and FK506, the purity of both are greater than 98%.2 Obtained FK520 derivative pimecrolimus, the 1H-NMR, 13C NMR spectroscopy, mass spectrometry consistent with its structural characteristics.According to the patent literature, we improved and simplified the response route, and reduce costs; pimecrolimus yield: 42.1%, the purity > 96%, mp 135.2-136.1℃, according to the data above, the product is confirmed to be pimecrolimus.Conclusion1 successfully separated the mixture of FK506 and FK520 using silver nitrate silica gel column chromatography. The separation method has good effect, the nature of both are stable, product purity is high.2 In the preparation of compound pimecrolimus, we have improved the patented process, prepared excellent chloride reagents, tried a variety of new routes, shorted the cycle of reaction, reduced the cost, increased the purity of the product, and researched the best ratio among the raw materials.3 Researched the HPLC determination of pimecrolimus, and made initial research on isomer, the work has great significance for the futrue research of pimecrolimus.