CONVERSION OF URACIL DERIVATIVES TO CYTOSINE DERIVATIVES

摘要

24205-676Abstract of the DisclosureA process is disclosed for producing a 4-0-sulfonyi-uracil derivative of the formula[wherein R1 is hydrogen, halogen, alkyl and alkoxy, R2 is glycosylhaving protected hydroxyls; and -SO2R3 is an organic sulfonyl]which comprises reacting an uracil derivative of the formula[wherein R1 and R2 are the same above]with an organic sulfonylating agent of the formula R3 SO2X[wherein R3SO2 is an organic sulfonyl and X is halogen] in thepresence of potassium carbonate. The obtained 4-0-sulfonyluracilis further subjected to amination. The processes are industriallyadvantageous and produce cytosine derivatives such as cytidine inhigh yield. The 4-0-sulfonyluracil derivative is useful as anintermediate for production of drugs such as cytidine diphosphatecholine whose generic name is Citicoline.