1: diethyl malonate With sodium hydride in isobutyramide T=20°C; 0.5 h; 2: N-benzyl-2H-pyridolt;2,3-dgt;lt;1.3gt;oxazine-2,4 1H-dione in isobutyramide T=110°C; 4 h; 3: With hydrogenchloride in isobutyramide; water T=0°C; pH=3;