TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The reaction (i) is done in a solvent comprising acetone, methylethylketone, dichloromethane, carbon tetrachloride, chloroform, benzene, fluorobenzene, benzonitrile, acetonitrile, propionitrile, ethyl acetate, butyl acetate, tetrahydrofuran (THF), methyl-THF, dioxane, toluene and/or xylene. The reaction (i) is done in the presence of a compound (iA) comprising magnesium sulfate, calcium chloride, alumina, sodium sulfate or molecular sieves derived from alumosilicates or zeolites. The reaction (i) is done in the presence of an acid (iB) comprising fluoroboric acid, hexafluorophosphoric acid, hydrochloric acid, hydrobormic acid, phosphoric acid, trifluoromethane sulfonic acid, methane sulfonic acid, 4-toluenesulfonic acid or sulfuric acid. The compound (II) has been prepared by (ii) reacting an aniline compound of formula (V) with compound (iiA) comprising a nitroalkane compound of formula (R12-O-NO), potassium nitrate or sodium nitrate in the presence of acid (iiB) comprising fluoroboric acid, hexafluorophosphoric acid, hydrochloric acid, hydrobormic acid, phosphoric acid or sulfuric acid. The method further comprises, after step (i): (iii) reacting (I) with an acid (iiic) in the presence of water to form the product (NBEA), which is a n-buten-1-al compound, where the n-buten-1-al compound is unsubstituted except for one phenyl residue of formula (X-res) at the C4 atom; or (iv) reducing (I) to form the substituted phenyl compound (I-red). The method further comprises, after step (iv), (v) reacting (I-red) with an acid (E) in the presence of water to form the substituted 4-phenyl-butyraldehyde compound (I-red-aid).R12 = 1-10C alkyl; andres = bond of residue (X-res), which connects the residue to the C4 atom of the n-buten-1-al compound.Preferred Components: The palladium source is palladium chloride, palladium acetate, bis(dibenzylideneacetone)palladium(0), tris(dibenzylideneacetone)dipalladium(0), trans-bis(benzonitrile)dichloropalladium(II), bis(acetonitrile)dichloropalladium(II), dichlorobis(triphenylphosphane)palladium(II), bis(tri-tert-butylphosphine)palladium(0), bis(tri-1-adamantylphosphine)palladium(0), tris(tri-1-adamantylphosphine)dipalladium(0), tetrakis(triphenylphosphine)palladium(0), and/or palladium on charcoal or on barium sulfate. (I) is an ester compound of formula (I-p-ester), (II) is an ester compound of formula (II-p-ester), and (V) is an ester compound of formula (V-p-ester). Preferred Definitions:    X = BF-; and    R4, R5 = methyl.    Provided that at least one of the substituents R1-R3 is not H; and when two of the three substituents R1-R3 are H, then the phenyl ring is not substituted on para position by F, OCH3 or acetyl.    ACTIVITY - Cytostatic.    MECHANISM OF ACTION - None given.    SPECIFIC COMPOUNDS - Preparation of 9 compounds (I) is specifically claimed e.g. 1-bromo-4-((E)-4,4-dimethoxybut-1-enyl)benzene of formula (Ia), 1-chloro-2-((E)-4,4-dimethoxybut-1-enyl)benzene, (4-((E)-4,4-dimethoxybut-1-enyl)phenyl)azinic acid, methyl 2-((E)-4,4-dimethoxybut-1-enyl)benzoate and methyl 4-((E)-4,4-dimethoxybut-1-enyl)benzoate. 2 Compounds (NBEA) are specifically claimed i.e. (E)-4-(2-chlorophenyl)but-2-enal of formula (N1) and (E)-4-(2-chlorophenyl)but-3-enal. 1 Compound (I-red) is specifically claimed i.e. methyl 2-(4,4-dimethoxybutyl)benzoate of formula (I-red-a). 1 Compound (I-red-aid) is specifically claimed i.e. 2-(4-oxo-butyl)-benzoic acid methyl ester of formula (I-red-aid-a).    EXAMPLE - Crotonaldehyde (0.29 ml) was added to a mixture of palladium acetate (18 mg), magnesium sulfate (0.46 g), and methanol (8.0 ml) at room temperature. Then 2-methoxycarbonyl-benzenediazonium tetrafluoro borate (439 mg) was added, the mixture was stirred for 1 minutes at 50 degrees C and then for 5.5 hours at room temperature. The resulting mixture was poured into an aqueous solution of sodium bicarbonate (150 ml), extracted with ethyl acetate (2 x 30 ml), the combined organic extracts were washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure, to provide a dark oil. The crude product was subjected to bulb-to-bulb distillation at 200 degrees C and 4 mbar to yield methyl 2-((E)-4,4-dimethoxybut-1-enyl)benzoate (250 mg).