合成路线:The reaction of 21-chloro-9beta-11beta-epoxy-16beta-methyl-17-(propionyloxy)pregn-4-en-3,20-dione (I) with ethyl orthoformate and p-toluenesulfonic acid in ethanol - dioxane gives 21-chloro-9beta-11beta-epoxy-3-ethoxy-16beta-methyl-17-(propionyloxy)pregna-3,5-dien-20-one (II),which is treated with perchloryl fluoride (ClO3F) in THF - water,yielding 21-chloro-9beta,11beta-epoxy-6alpha-fluoro-16beta-methyl-17-(propionyloxy)pregn-4-ene-3,20-dione (III).The addition of HF to the epoxy ring of (III) by means of the complex urea - HF affords 21-chloro-6alpha,9alpha-difluoro-11beta-hydroxy-16beta-methyl-17-(propionyloxy)pregn-4-ene-3,20-dione (IV),which is finally dehydrogenated with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in refluxing dioxane.
参考文献标题:Process for the preparation of polyhalogenated steroids
文献作者:Kalvoda,J.; Anner,G.(Novartis AG)
参考来源:CH 632000; DE 2743069
合成路线:The reaction of 21-chloro-9beta-11beta-epoxy-16beta-methyl-17-(propionyloxy)pregn-4-en-3,20-dione (I) with ethyl orthoformate and p-toluenesulfonic acid in ethanol - dioxane gives 21-chloro-9beta-11beta-epoxy-3-ethoxy-16beta-methyl-17-(propionyloxy)pregna-3,5-dien-20-one (II),which is treated with perchloryl fluoride (ClO3F) in THF - water,yielding 21-chloro-9beta,11beta-epoxy-6alpha-fluoro-16beta-methyl-17-(propionyloxy)pregn-4-ene-3,20-dione (III).The addition of HF to the epoxy ring of (III) by means of the complex urea - HF affords 21-chloro-6alpha,9alpha-difluoro-11beta-hydroxy-16beta-methyl-17-(propionyloxy)pregn-4-ene-3,20-dione (IV),which is finally dehydrogenated with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in refluxing dioxane.
参考文献标题:Halobetasol Propionate
文献作者:Prous,J.; Castar,J.
参考来源:Drugs Fut 1991,16(7),614
合成路线:The reaction of 21-chloro-9beta-11beta-epoxy-16beta-methyl-17-(propionyloxy)pregn-4-en-3,20-dione (I) with ethyl orthoformate and p-toluenesulfonic acid in ethanol - dioxane gives 21-chloro-9beta-11beta-epoxy-3-ethoxy-16beta-methyl-17-(propionyloxy)pregna-3,5-dien-20-one (II),which is treated with perchloryl fluoride (ClO3F) in THF - water,yielding 21-chloro-9beta,11beta-epoxy-6alpha-fluoro-16beta-methyl-17-(propionyloxy)pregn-4-ene-3,20-dione (III).The addition of HF to the epoxy ring of (III) by means of the complex urea - HF affords 21-chloro-6alpha,9alpha-difluoro-11beta-hydroxy-16beta-methyl-17-(propionyloxy)pregn-4-ene-3,20-dione (IV),which is finally dehydrogenated with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in refluxing dioxane.
参考文献标题:The effect of topically applied compound F in selected dermatoses
文献作者:Witten,V.H.; Sulzberger,M.B.
参考来源:J Invest Dermatol 1952,19101-2
产品链接: CAS No. 66852-54-8›› 产品链接: CAS No.98651-66-2››