L. Strekowski,, M. Ismail, H. H. Zoorob
1999
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0
Influential Citations
1
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Journal
Heterocyclic Communications
Abstract
The treatment of 5-(4-chlorobutanoyl)-l,3-dimethylbarbituric acid (1) with K 2 C 0 3 furnishes a 5(tetrahydrofuran-2-ylidene)barbituric acid derivative 2. A similar reaction of 5-chloroacetyl-l,3dimethylbarbituric acid ( 4 ) with Et3N yields a furanouracil 5. Synthetic transformations of 2 and 5 to 5-(ωheteroarylalkanoyl)-l,3-dimethylbarbituric acids and synthesis of other furanouracils from 5 are described. Recently we have reported an efficient acylation of 1,3-dimethylbarbituric acid (1). In particular, the reaction of a sodium salt of this compound with 4-chlorobutanoyl chloride or chloroacetyl chloride in pyridine provides an easy access to the respective 5-(o)-chloroalkanoyl)1,3-dimethylbarbituric acids 1 (structure in Scheme 1) and 4 (Scheme 2). In continuation of our work on the synthesis of new pyrimidine derivatives of potential biological activity (1 ,2) we now describe versatile chemistry of compounds 1 and 4. It was reasoned that the chlorine atom in 1 or 4 could be substituted by the reaction with various nucleophiles. In particular, the treatment of 1 with imidazole (1.5 equiv., DMF, reflux for 8h) was expected to give compound 3. To our surprise this reaction furnished 1,3-dimethylbarbituric acid in an almost quantitative yield and an additional unidentified product that was highly soluble in water under neutral, S c h e m e 1