1: methyl 3-(N-methyl-N-phenylamino)-3-oxopropanoate With sodium hydride in N,N-dimethyl-formamide T=80°C; 1 h; 2: 1-methyl-2H-3,1-benzoxazine-2,4(1H)-dione in N,N-dimethyl-formamide T=115°C; 1 h;

water; lithium hydroxide hydrate in tetrahydrofuran T=20°C; 1 h;