TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The reaction is carried out in aromatic hydrocarbons, cyclic or acyclic ethers, preferably in tetrahydrofuran or diethyl ether (both preferred), benzene, toluene, xylenes, cumene, chlorobenzene, dichlorobenzenes, nitrobenzene, pyridine, tert-butylbenzene, tert-butyl methyl ether, cyclopentyl methyl ether, methyl tetrahydrofuran or dioxane. In the process, the precursor phosphonium salt, (VII) and the solvent are placed in the reaction vessel, and the base is added subsequently in solid form or as solution to this reaction mixture. After completion of the reaction, the solvent is distilled off and a non-polar solvent is added. The triphenylphosphine oxide is precipitated with the addition of the non-polar solvent, and the precipitate is filtered off. The halogenated styrene product is: distilled from the non-polar solvent solution; and worked-up under non-aqueous conditions. The process further comprises: an upstream process step (A-1) comprising obtaining (VII) by reacting substituted phenyl compounds of formula (VI) with magnesium (in form of turnings or powder) or Grignard reagent, and with a di- or trifluoroacetic acid derivative of formula (R5CF2COR7), where Grignard reagent is a 1-4C alkyl magnesium halogenide; (A-3) reacting (VIII) with substituted 4-bromo-benzaldehyde oxime compounds of formula (IV) in the presence of chlorinating agent and base to give substituted 3-(4-bromo-phenyl)-5-phenyl-4,5-dihydro-isoxazole compounds of formula (XV); (A-4) reacting (XV) with carbon monoxide and amine of formula (NR8R9) in the presence of palladium catalyst to give substituted isoxazoline compounds of formula (I); and upstream step (B) comprising reacting substituted 4-bromo-phenylamine compounds of formula (II) with formoxime of formula (R6-HC=N-OH) to give (IV). The step (A-3) comprises first reacting (IV) with the chlorinating agent to give intermediate 4-bromo-N-hydroxybenzimidoyl chloride compounds of formula (V) and then reacting (V) with (VIII) in the presence of a base to give (XV). The pressure of the reaction in step (A-4) is 0.9-100, preferably 0.9-20 bar. The step (B) comprises reacting (II) with formoxime to give substituted 4-bromo-benzaldehyde compounds of formula (III) in the presence of sodium nitrite, and reacting (III) with hydroxylamine to give (IV). (II) is obtained in a further upstream process comprising bromination of substituted phenylamine compounds of formula (IX).R7 = piperidinyl, morpholinyl or piperazinyl (all are bound via their N atom), OH, F3CCOO, halo, 1-6C alkoxy, N(CH3)2, N(C2H5)2 or N(OCH3)CH3;X = halo, preferably Cl or Br;R1 = H, CH3, CF3, CH2CH3, CH2CF3, Cl, Br, I, CN, NO2, SF5, OCH3, OCF3 or OCHF2;R8 = 1-6C alkyl (optionally substituted with n R10), H or Z-A;Z = bond, CH2, CH2CH2 or C=O;A = 2,2-dichloro-cyclopropyl, pyridin-2-yl, pyrimidin-2-yl, 2-chloro-pyridin-6-yl, 5-chloro-pyridin-2-yl, 4-chloro-pyridin-2-yl, 3-chloro-pyridin-2-yl, 2-chloro-thiazol-4-yl, thiazol-4-yl, pyridin-3-yl, pyridin-4-yl, pyrimidin-4-yl, pyridazin-3-yl, 3-chloro-pyridazin-6-yl, oxazol-4-yl, 2-chloro-oxazol-4-yl, (1,2,4)oxadiazol-3-yl, 1H-(1,2,4)triazol-3-yl, 4-methyl-1H-(1,2,4)triazol-3-yl, 2,2-dichloro-1-methyl-cyclopropyl, 2-chloro-pyridin-5-yl, 3-chloro-pyridin-5-yl, 2-chloro-pyridin-3-yl, 4-chloro-pyridin-3-yl, 3-chloro-pyridin-4-yl, 2-chloro-pyridin-4-yl, 2-chloro-pyrimidin-4-yl or 5-chloro-1H-(1,2,4)triazol-3-yl; eitherR10 = H, halo, CN, azido, NO2, SCN, SF5, 1-6C (halo)alkyl, 1-6C alkoxy-(1-6C alkyl), 3-8C (halo)cycloalkyl, 2-6C (halo)alkenyl, 2-6C (halo)alkynyl, Si(R17)2R18, OR11, OSO2R11, SR11, -S(O)mR11, S(O)nN(R12)R13, N(R12)R13, C(=O)N(R12)R13, C(=S)N(R12)R13, C(=O)OR11, phenyl (optionally substituted by 1-5 radicals R14), or 3-7 membered saturated, partially unsaturated or aromatic heterocyclic ring containing 1-3 heteroatoms (N, O, S, NO, SO or SO2) (optionally substituted by at least one R14); ortwo vicinal radicals R10 = (=CR15R16), (=S(O)mR11), (=S(O)mN(R12)R13), (=NR12, =NOR11) or (=NNR12); ortwo CR10 = 3-8 membered saturated or partially unsaturated carbocyclic or heterocyclic ring containing 1-3 heteroatoms (N, O, S, NO, SO or SO2);R11 = 1-6C alkyl, 2-6C alkenyl, 2-6C alkynyl, 3-8C cycloalkyl (all optionally halogenated and/or oxygenated, and/or substituted with 1-2 T1), H or CN; eitherR12, R13 = 1-6C alkyl, 2-6C alkenyl, 2-6C alkynyl, 3-8C cycloalkyl (all optionally halogenated and/or oxygenated, and/or substituted with 1-2 T1), H or CN; orNR12R13 = 3-7 membered saturated or unsaturated ring by forming a 2-6C alkylene chain (optionally containing 1-2 O, S or N, and optionally substituted with halo, 1-4C haloalkyl or 1-4C (halo)alkoxy);T1 = phenyl, benzyl, pyridyl or phenoxy (all optionally halogenated and/or substituted with 1-3 1-6C (halo)alkyl, 1-6C (halo)alkoxy or (1-6C alkoxy)carbonyl), 1-4C alkoxy, 1-6C (halo)alkoxy, 1-6C (halo)alkylthio, 1-6C alkylsulfinyl, 1-6C alkylsulfonyl, trimethylsilyl, triethylsilyl or tert-butyldimethylsilyl; eitherR14 = H, CN, 1-6C alkyl, 2-6C alkenyl, 2-6C alkynyl, 3-8C cycloalkyl (optionally halogenated and/or oxygenated, and/or substituted with 1-2 T1); or2R14 = =C(1-4C alkyl)2, =N(1-6C alkyl), =NO(1-6C alkyl) or (=O); orNR14 = 3-7 membered saturated or unsaturated ring by forming 2-6C alkylene chain containing 1-2 O, S or N (optionally substituted with halo, 1-4C haloalkyl, 1-4C (halo)alkoxy); eitherR15, R16 = 1-6C alkyl, 2-6C alkenyl, 2-6C alkynyl or 3-8C cycloalkyl (all optionally halogenated and/or oxygenated, and/or substituted with 1-2 T2), H, halo, CN, azido, NO2, SCN or SF5; orCR15R16 = (=C(1-4C alky)2), (=N(1-6C alkyl), (=NO(1-6C alkyl) or (=O);T2 = phenyl, benzyl, pyridyl or phenoxy (all optionally halogenated and/or substituted with 1-3 1-6C (halo)alkyl, 1-6C (halo)alkoxy, (1-6C alkoxy)carbonyl, (1-6C alkyl)amino, di-(1-6C alkyl)amino), 1-4C alkoxy, 1-6C (halo)alkoxy, 1-6C (halo)alkylthio, 1-6C alkylsulfinyl, 1-6C alkylsulfonyl, trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, OH or SH;R17, R18 = 1-4C alkyl, 3-6C cycloalkyl, (1-4C alkoxy)-1-4C alkyl, phenyl or benzyl;R9 = H, CH3, CH2CH3, CH2CH2CH3, C(=O)CH3 or C(=O)OCH3; andn = 1-4.Preferred Components: The methylenating agent used in the process is triphenylmethyl phosphonium bromide or triphenylmethyl phosphonium chloride (both preferred), freshly powdered triphenylmethyl phosphonium iodide, and which is activated by the addition of a base. The base is alkali metal alcoholates (preferred), organolithium reagents, lithium or sodium amides. The base is potassium methoxide or sodium methoxide. The chlorinating agent is chlorine, sodium hypochlorite, N-chlorosuccinimide or chloramine T. The base is triethylamine, pyridine, potassium carbonate, sodium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate or ethyl magnesium bromide. The brominating agent is bromine, N-bromosuccinimide, dibromo dimethyl hydantoin, aqueous hydrogen bromide/hydrogen peroxide, pyridinium hydrobromide, bromine pentafluoroantimonate hydrofluoride or 2,4,4,6-tetrabromo-cyclohexa-2,5-dienone. EXAMPLE - Potassium tert-butoxide (0.62 g) was added to a suspension of methyl-triphenylphosphonium iodide in tetrahydrofuran. After 30 minutes, 3,5-dichloro-2,2,2-trifluoro acetophenone (1.2 g) was added and the reaction mixture was stirred over night. The reaction mixture was separated between tert-butyl methyl ether and aqueous ammonium chloride solution. The organic layer was separated and the solvent was removed in vacuum to obtain 1,3-dichloro-5-(1-trifluoromethyl-vinyl)-benzene (61% yield).