Methyl 2-benzoylamino-3-dimethylamonopropenoate in the synthesis of heterocyclic systems. A simple synthesis of amino derivatives of isomeric naphthopyranones and naphthodipyranones

A simple synthesis of the amino derivatives of 3H-naphtho2,1-b]pyran-3-one 5b-d, 8,11 , and 20 , 2H-naphtho1,2-b]pyran-2-one 14 and 19 , 2H,6H-naphtho1,2-b:3,4-b']dipyran-2,6-dione 9 , 2H,11H-naphtho2,1-b:3,4-b']dipyran-2,11-dione 12 , and 3H,9H-naphtho1,2-b:5,6-b']dipyran-3,9-dione 15 from the corresponding monohydroxynaphthalenes 2c,d , dihydroxynaphthalenes 2b, 7, 10 , and 13 , and tetralones 16 and 17 with methyl 2-benzoylamino-3-dimethylaminopropenoate (3) in acetic acid is described.