Brina Ornik, Z. Čadež, B. Stanovnik
May 1, 1990
Citations
0
Influential Citations
20
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
Methyl 2-benzoylamino-3-dimethylaminopropenoate (1) reacts with carbocyclic and heterocyclic 1,3-diketones or potential 1,3-diketones, such as 1,3-cyclohexanediones 2–4, and 4-hydroxy-2H-1-benzopyran-2-one derivative 17, in acetic acid to afford the corresponding 3-benzoylamino substituted 5-oxo-5,6,7,8-tetrahydro-2H-1-benzopyran-2-ones 5–7, and 2H,5H-pyrano[3,2-c][1]benzopyran-2,5-dione derivative 18. 1-Naphthol (12) and 2-naphthol (13) produce the isomeric 2H-naphtho[1,2-b]pyran-2-one (14) and 3H-naphtho[2,1-b]pyran-3-one (15) derivatives, respectively. Ethyl cyclopentanone-2-carboxylate (8) and ethyl cyclohexanone-2-carboxylate (9) do not react under these conditions, while in polyphosphoric acid the cyclization of the reagent 1 is taking place to give 4-dimethylaminomethylene-2-phenyl-5(4H)-oxazolone (10). 4,6-Dihydroxypyrimidine derivative 19 affords in acetic acid the noncyclized intermediate 20, which can be further transformed in polyphosphoric acid into 7H-pyrano[2,3-d]pyrimidin-7-one derivative 21.