1: 5-amino-2,8-dimethyl-4H-chromen-4-one With sulfuric acid; sodium nitrite T=0°C; 1.5 h; 2: sodium cyanide; copper (I) cyanide in water; ethyl acetate T=0°C; 0.75 h;

sodium nitrite in sulfuric acid; water; ethyl acetate

N-bromosuccinmide in tetrachloromethane

N-bromosuccinmide; 2,2'-azo-bisisobutyronitrile in tetrachloromethane Reflux;