A red fluorescent dye able to emit red light is prepared through reaction between substituted naphthenone solution, alkaline emine compound and catalyst to obtain enamine compound, thermal reflux reaction on 2,2,6-trimethyl-1,3-dioxin-4-one at 110-160 deg.c for 3-10 hr to obtain 2-methyl-4H-pyran-4-one, reaction on malonomitrile and catalyst to obtain substituted 4-diacynomethylene-2-methyl-4H-pyran, adding arylaminal and catalyst, thermal reflux for 5-30 hr, distilling to remove solvent, leaching the solid, and drying. It can be used as luminescent material in optical and photoelectric devices. |