Five-membered 2,3-dioxo heterocycles: LXI. Reaction of 3-aroyl-1 H -pyrrolo[2,1- c ][1,4]benzoxazine-1,2,4-triones with α -enamino esters. Crystalline and molecular structure of methyl 11-benzoyl-2- o -hydroxyphenyl-3,4,10-trioxo-6,9-diphenyl-7-oxa-2,9-diazatricyclo[6.2.1.01,5]undec-5-ene-8-carboxylate |