An efficient method has been developed for the preparation of halo derivatives of 6-methyluracil by employing oxidative halogenation. Elemental halogens and potassium halides were used as the halogenating agents, while NaNO3 and H2O2 were used as the oxidizing agents. Iodination of 6-methyl-uracil leads to 5-iodo-6-methyluracil as the single reaction product, while bromination or chlorination lead to 5-halo-6-methyluracil, 5,5-dihalo-6-hydroxy-6-methyl-5,6-dihydrouracil, or their mixture depending on the acidity of the medium and the ratio of the substrate and reagents. Bromination of 5-chloro-6-methyluracil leads to 5-bromo-5-chloro-6-hydroxy-6-methyl-5,6-dihydrouracil, while chlorination of 6-methyl-, 5-bromo-6-methyl-, and 5-chloro-6-methyluracils using gaseous chlorine yields 5,5-dichloro-6-hydroxy-6-methyl-5,6-dihydrouracil.
Halogenation and nitration of 1-carboxymethyl-5-methyluracil. Halophilic reaction involving acetic anhydride
作者:I. B. Chernikova、M. S. Yunusov
DOI:10.1007/s11172-020-3015-0
日期:2020.11
1-Carboxymethyl-5-halo-6-hydroxy-5-methyl-5,6-dihydrouracils and 1-carboxymethyl-6-hydroxy-5-methyl-5-mtro-5,6-dihydrouracils were synthesized for the first time by oxidative halogenation and nitration of 1-carboxymethyl-5-methyluracil. Dihydrouracil derivatives bearing a Br atom at position C(5) and a hydroxy group at position C(6) treated with Ac2O undergo deoxyhalogenation.
Novel derivatives of pyrimid-2-one having interesting pharmacological properties are described. The compounds of the invention have been found to be of use in the control of, and in particular in the inhibition of the metaphase of malignant tumours and leukaemias. Processes for the preparation of the novel compounds and pharmaceutical compositions containing them are also described.
Verfahren zur Herstellung von Pyrimidindionen und Dihydroxypyrimidinen, sowie neue Pyrimidindione und Dihydroxypyrimidine
申请人:BAYER AG
公开号:EP0151939A2
公开(公告)日:1985-08-21
57 2,4-(1H,3H)-Pyrimidindione, die dazu tautomeren 2,4-Dihydroxypyrimidine und 4,6-Dihydroxypyrimidine wurden hergestellt, indem man Fluor und oder Chlor enthaltende Pyrimidine mit wässrigen Säuren oder Alkalien hydrolysiert. Die erhaltenen Pyrimidindione und Dihydroxypyrimidine sind zum größten Teil neu.