NOVELTY - Preparing alizarin derivatives (I) comprises: (A) obtaining 5-hydroxy-(1,4)naphthoquinone derivatives (II) using 5,6,8-trihydroxy-(1,4)naphthoquinone derivatives (III); and (B) obtaining alizarin derivatives (I) using (II) obtained in the step (A).    USE - The method is useful for preparing alizarin derivatives (I), which are used: for surface modification method for inorganic compound solid materials; photoelectric conversion films; photoelectric conversion elements; electrophotographic photoreceptors (all claimed); as lake pigments for organic electronics applications (including colorant-sensitized solar cell, organic thin film solar cell, organic imaging element, organic semiconductor, organic electroluminescent element, photosensors and electrophotographic photoreceptor); in color material applications (including ink for inkjet, color copies in sublimation transfer mode, ink dye, color filter, silver halide photosensitive materials, printing, optical recording media and colorants for food); in physiologically active materials (including anticancer agent and hair growth promoter); and in electrolyte solutions; as negative-type semiconductor.    ADVANTAGE - The method: utilizes purpurin as a starting material, thus the method is simple and cost effective; provides alizarin derivatives which allows fabrication of photoelectric conversion element having large area at low temperature and at low cost; provides alizarin derivatives having high solubility and homogeneity in the undercoat layer coating liquid and excellent amorphous property, while eliminating change in the bonding performances of inorganic fine particles including metal oxide, and grain boundary generation in the interface of the inorganic fine particles; and provides alizarin derivatives which results in electrophotographic photoreceptors having improved image quality and preservation property, without generation of abnormal densities, ghosts and fogging/black spots.    DETAILED DESCRIPTION - Preparing alizarin derivatives of formula (I) comprises: (A) obtaining 5-hydroxy-(1,4)naphthoquinone derivatives of formula (II) using 5,6,8-trihydroxy-(1,4)naphthoquinone derivatives of formula (III); and (B) obtaining alizarin derivatives (I) using (II) obtained in the step (A).    R1 = H or substituent; either    L = -C(R1a)(R2a)(R3a) (when n is 1); or    L = divalent 2-20C linkage group (optionally substituted) (when n is 2); or    L = trivalent 2-30C linkage group (optionally substituted) (when n is 3);    R1a, R2a and R3a = 1-30C alkyl, 6-30C aryl (both optionally substituted) or H;    at least one of R1a, R2a and R3a = 1-30C alkyl, 6-30C aryl (both optionally substituted);    P1 = atomic group including H, C, O, S, Si or B, and which is needed to form a ring structure with two adjacent O atoms and two C atoms;    Q = atomic group which is needed to form aromatic ring or heteroaromatic ring with adjacent carbon atoms; and    n = 1-3.    INDEPENDENT CLAIMS are also included for:    (1) alizarin derivatives of formula (V);    (2) surface modification method for an inorganic compound solid material, comprising bonding the alizarin derivatives (V) to a surface of an inorganic compound solid material through an oxygen atom obtained by removal of a hydrogen atom from at least one hydroxy group contained in (V);    (3) a photoelectric conversion film comprising the alizarin derivatives (V);    (4) a photoelectric conversion element comprising the alizarin derivatives (V); and    (5) an electrophotographic photoreceptor comprising a conductive base, an undercoat layer on the conductive base and a photoconductive layer, where the undercoat layer comprises the alizarin derivatives (V).    R2, R3 = 1-30C alkyl, 6-30C aryl, 1-30C alkoxy (all optionally substituted) or H; and    m = 0-4.