NEW MATERIAL:A dibenzofuran derivative expressed by formula I (R1 and R2 are the same or different lower alkyl which may have molecule; R3 is H or acyl).

EXAMPLE: 2,6-Di-tert-butyl-8-hydroxybenzofuran-1,4-dione.

USE: Assuming bright orange color, very stable to light, useful as a dyestuff in various fields, changing the hue depending on the concentration thereof when converted into a solution, giving orange color in the case of a high-concentration solution but assuming yellow color in the case of a low concentration and usable properly in orange-yellow according to the purpose by adjusting the concentration thereof.

PREPARATION: A bis-quinone derivative expressed by formula II as a raw material is dissolved in an organic solvent, e.g. pyridine or alcohol and irradiated with natural or artificial light to afford the aimed compound expressed by formula I.