Heterocyclic transformations. Part 5: Studies in reactions of 6-methyl -l,3-oxazine-2,4(3H)-dione with arylamines—a facile synthesis of 1-aryl-6-methyluracils
作者:Harjit Singh、Palwinder Singh、Pawan Aggarwal、Subodh Kumar
DOI:10.1039/p19930000731
日期:——
6-Methyl-1,3-oxazine-2,4(3H)-dione 1 reacts with 2 equiv. arylamines 3 at 150-160-degrees-C to give 1-aryl-6-methyluracils 5 or 1-aryl-3- (3-aryliminobutanoyl) ureas 4. The latter-as well as mixtures of 1 and 3 (2 equiv.) on refluxing, in isopentanol in some cases or in acetic acid in general-provide a facile synthesis of 5. The role of the stoichiometric excess of arylamines as against an equiv. of an alkylamine in similar reactions has been rationalized.