TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (disclosed): Phosphorus acid triethyl and phenyl ring containing compound of formula (II) are reacted at 160-200degreesC for 2-6 hours, to obtain phosphorus acid diethyl group containing compound of formula (III). The phosphorus acid diethyl group containing compound reacts with carbonyl group containing compound of formula (IV) in presence of catalyst, to obtain triphenyl ring containing compound of formula (V). Phosphorus acid triethyl reacts with substituted propylene compound of formula (VI), to obtain phosphorus acid diethyl group containing propylene compound of formula (VII). Phosphorus acid diethyl group containing propylene compound and carbonyl group containing compound of formula (VIII) reacts to obtain aromatic group containing butylene compound of formula (IX). Triphenyl ring containing compound reacts with aromatic amine of formula: Ar1-NH2, to obtain aromatic amide of formula (X). The aromatic amide and aromatic group containing butylene compound reacts in presence of catalyst, to obtain diphenylamine derivative of formula (I). SPECIFIC COMPOUNDS - 5 diphenylamine derivative are disclosed, such as (4-butyl-phenyl)-(4-((1E,3E)-4-phenyl-buta-1,3-dienyl)-phenyl)-(4-((E)-2-(4-((E)-styryl)-phenyl)-vinyl)-phenyl)-amine, (4-butyl-phenyl)-(4-((E)-styryl)-phenyl)-(4-((E)-2-(4-((E)-styryl)-phenyl)-vinyl)-phenyl)-amine, (4-butyl-phenyl)-(4-((1E,3E)-4-phenyl-buta-1,3-dienyl)-phenyl)-(3-((E)-2-(4-((E)-styryl)-phenyl)-vinyl)-phenyl)-amine, (4-((E)-2-biphenyl-4-yl-vinyl)-phenyl)-(4-butyl-phenyl)-(4((E)-2-(4-((E)-styryl)-phenyl)-vinyl)-phenyl)-amine and (2-ethyl-6-methyl-phenyl)-(4-((1E,3E)-4-phenyl-buta-1,3-dienyl)-phenyl)-(4-((E)-2-(4-((E)-styryl)-phenyl)-vinyl)-phenyl)-amine.    EXAMPLE - Bromine atom containing compound (in g) (20) of formula (XI) and phosphorus acid triethyl acid (30) were added, stirred and heated at 180degreesC for 8 hours. Then, the reaction mixture was cooled to room temperature and excess phosphorus acid triethyl ester was removed, to obtain phosphorus acid diethyl group containing compound (27) of formula (XII). Phosphorus acid diethyl group containing compound (50), tetrahydrofuran (100 ml), aldehyde group containing compound (10.2) of formula (XIII) and 28% sodium methoxide (15.2) were added and stirred at 0degreesC for 30 minutes, to obtain bromo triphenyl compound (15) of formula (XIV). Chlorine atom containing compound (20) of formula (XV) and phosphorus acid triethyl (43) were heated and stirred at 180degreesC for 8 hours, to obtain phosphorus acid diethyl group containing compound (29) of formula (XVI). Phosphorus acid diethyl group containing compound (15), tetrahydrofuran (100 ml), 28% sodium methoxide (18.2) and bromo benzaldehyde of formula (XVII) were stirred at room temperature for 12 hours, to obtain bromo aromatic compound of formula (XVIII). Bromo triphenyl compound (10) reacts with aromatic amine (4.1) of formula (XIX) and di-cyclohexyl phosphine (0.05) were heated at 12degreesC for 5 hours, to obtain aromatic amide of formula (XX). The aromatic amide reacts with bromo aromatic compound, to obtain (4-butyl-phenyl)-(4-((1E,3E)-4-phenyl-buta-1,3-dienyl)-phenyl)-(4-((E)-2-(4-((E)-styryl)-phenyl)-vinyl)-phenyl)-amine (11) in a yield of 75degreesC. The diphenylamine derivate had excellent solubility. The photoreceptor layer of electrophotographic photoreceptor formed using diphenylamine derivative had excellent sensitivity.