EP3436552B1 - Use of triarylbenzene derivatives as tracers for marking liquid fuels and motor fuels, liquid fuels and motor fuels containing such derivatives and corresponding processes - Google Patents

Description

The present invention relates to the use of triarylbenzene derivatives as labeling tracers for fuels and liquid fuels; fuels and liquid fuels containing such derivatives; a process for marking fuels and liquid fuels with such derivatives; and a method of determining whether fuels or liquid fuels initially containing these tracers have been tampered with, used illegally or stolen.

The labeling of fuels and liquid fuels with various types of chemical markers is well known in the art. A variety of compounds have been used for this purpose, as well as many analytical techniques for the detection of labels (eg, gas chromatography coupled with mass spectrometry). An important application is to mark combustible fuels according to their level of taxation. The deliberate disposal of the tracker for illegal purposes is an important issue. As tracers have been dyes heretofore, “removal methods” have been referred to as “bleaching methods”. These methods are physical (for example: adsorption on carbon or on silica gel) or chemical (for example: acid or basic treatment). Therefore, these markers must be resistant to such removal methods, be fully compatible with fuels and combustibles. liquids, and be identifiable by an appropriate analytical method.

Fraud concerning fuels or liquid fuels covers various forms of activity: falsification by laundering or cutting, illegal use, smuggling and theft. Falsification by laundering concerns the transformation of a fuel or liquid fuel with a low tax rate into fuel or liquid fuel with a higher tax rate, for example - in France - the transformation of domestic fuel oil into diesel. Falsification by cutting concerns the dilution of a fuel or liquid fuel with a high tax rate by a fuel or liquid fuel at a low tax rate. Illegal use refers to the illegal use of a fuel or liquid fuel with a low tax rate instead of a fuel or liquid fuel with a higher tax rate. Smuggling is the purchase of fuel or liquid fuel at low tax rates in one country for resale in another country where taxes are higher.

WO2012 / 153132 A1 describes aromatic organic markers substituted by at least one bromine and / or one fluorine atom, and / or one or more fluoroalkyl groups. The combustion of fuels labeled with such compounds can produce hydrogen bromide and / or hydrogen fluoride in the flue gases. Hydrogen bromide and fluoride are known to be particularly corrosive to the engine. Hydrogen fluoride is well known to be highly toxic to people and the environment.

WO2014 / 008164 describes aryl and trityl alkyl ethers as tracers for labeling hydrocarbons. Such tracers appear not to exhibit good resistance to the abovementioned elimination methods.

US 5,981,283 A describes the use of a wide variety of organic compounds for the labeling of petroleum products, including 1,3,5-triphenylbenzene. This tracer compound appears not to exhibit good resistance to the abovementioned elimination methods.

US 7,858,373 describes the use of a variety of organic compounds for use in the marking of liquid fuels such as hydrocarbons and oils. Combinations of markers can be used as digital labeling systems, the ratio of the concentration of each marker forming a code of the labeled product.

There therefore still remains a need for additional chemical markers compatible with fuels and liquid fuels, detectable in such a complex medium and resistant to physical and chemical bleaching methods, at least to the physical method of bleaching by activated carbon and / or by silica.

Surprisingly, it has been found that certain triarylbenzenes are particularly effective for the labeling of fuels and liquid fuels. In addition, it has been shown that these triarylbenzenes are particularly resistant to bleaching attempts. chemical and physical. In addition, most of these triarylbenzenes contain only carbon and hydrogen and the combustion of these compounds used as markers produces only carbon dioxide and water.

dans laquelle :

• le noyau benzénique A est facultativement substitué dans au moins une des positions 2, 4 ou 6 par :
  • un radical alkyle, linéaire, ramifié ou cyclique, en C₁-C₁₈, facultativement substitué par au moins un halogène et/ou facultativement interrompu par au moins un oxygène ; ou
  • un radical alcoxy, linéaire, ramifié ou cyclique, en C₁-C₁₈, facultativement substitué par au moins un halogène et/ou facultativement interrompu par au moins un oxygène ; ou
  • un radical alcényle, linéaire, ramifié ou cyclique, en C₂-C₁₈, facultativement substitué par au moins un halogène et/ou facultativement interrompu par au moins un oxygène ;
• les noyaux benzéniques B, C et D sont substitués, indépendamment les uns des autres, dans au moins une position ortho, méta ou para par rapport au noyau benzénique A par :
  • un radical alkyle, linéaire, ramifié ou cyclique, en C₁-C₁₈, facultativement substitué par au moins un halogène et/ou facultativement interrompu par au moins un oxygène ; ou
  • un radical alcoxy, linéaire, ramifié ou cyclique, en C₁-C₁₈, facultativement substitué par au moins un halogène et/ou facultativement interrompu par au moins un oxygène ; ou
  • un radical alcényle, linéaire, ramifié ou cyclique, en C₂-C₁₈, facultativement substitué par au moins un halogène et/ou facultativement interrompu par au moins un oxygène ; ou
  • un halogène ;
    au moins un noyau benzénique B, C et D pouvant par ailleurs comporter un cycle aliphatique à 5-7 chaînons accolé à celui-ci, par exemple un cycle à 6 chaînons,

à la condition que, lorsque le noyau benzénique A n'est pas substitué et que les noyaux benzéniques B, C et D sont chacun substitués par un méthyle, ce dernier n'est pas en position para par rapport au noyau benzénique A.The present invention therefore firstly relates to the use as a tracer for marking fuels and liquid fuels of at least one compound of Formula I:

in which :

• the benzene ring A is optionally substituted in at least one of the 2, 4 or 6 positions by:
  • an alkyl radical, linear, branched or cyclic, C ₁ -C ₁₈ , optionally substituted with at least one halogen and / or optionally interrupted by at least one oxygen; or
  • an alkoxy radical, linear, branched or cyclic, C ₁ -C ₁₈ , optionally substituted by at least one halogen and / or optionally interrupted by at least one oxygen; or
  • an alkenyl radical, linear, branched or cyclic, C ₂ -C ₁₈ , optionally substituted with at least one halogen and / or optionally interrupted by at least one oxygen;
• the benzene rings B, C and D are substituted, independently of one another, in at least one position ortho, meta or para with respect to the benzene ring A by:
  • an alkyl radical, linear, branched or cyclic, C ₁ -C ₁₈ , optionally substituted with at least one halogen and / or optionally interrupted by at least one oxygen; or
  • an alkoxy radical, linear, branched or cyclic, C ₁ -C ₁₈ , optionally substituted by at least one halogen and / or optionally interrupted by at least one oxygen; or
  • an alkenyl radical, linear, branched or cyclic, C ₂ -C ₁₈ , optionally substituted with at least one halogen and / or optionally interrupted by at least one oxygen; or
  • a halogen;
    at least one benzene ring B, C and D which may moreover contain a 5-7-membered aliphatic ring attached thereto, for example a 6-membered ring,

with the proviso that when the benzene ring A is unsubstituted and the benzene rings B, C and D are each substituted with a methyl, the latter is not in the para position with respect to the benzene ring A.

Note that, in Formula 1, any atom can be replaced by one of its isotopes.

Preferably, the benzene ring A is unsubstituted or substituted by C ₁ -C ₁₈ alkoxy.

• un radical alkyle, linéaire, ramifié ou cyclique, en C₁-C₁₈, notamment en C₁-C₁₂, en particulier en C₁-C₆, facultativement substitué par au moins un halogène ; ou
• au moins un halogène.

Preferably, the benzene rings B, C and D are substituted by:

• an alkyl radical, linear, branched or cyclic, C ₁ -C ₁₈ , in particular C ₁ -C ₁₂ , in particular C ₁ -C ₆ , optionally substituted by at least one halogen; or
• at least one halogen.

A halogen falling within the definition of Formula I can be F, Cl, Br and I, and in particular F, Cl and Br.

The compound of Formula I can in particular be chosen from:

Particularly preferably, the compound of Formula I is:

A subject of the invention is also a fuel or liquid fuel containing as labeling tracer at least one compound of Formula I.

• les carburants ou combustibles liquides obtenus à partir du pétrole parmi lesquels on peut citer l'essence, le gazole, le fuel domestique, le kérosène, le pétrole lampant ;
• les carburants ou combustibles liquides obtenus à partir des végétaux tels que les biocarburants parmi lesquels on peut citer les huiles végétales, l'éthanol, le butanol, l'éthyl tert-butyl éther (ETBE), les esters méthyliques d'acide gras.

As fuel or liquid fuel, we can cite:

• fuels or liquid fuels obtained from petroleum, among which may be mentioned gasoline, gas oil, domestic fuel oil, kerosene, kerosene;
• fuels or liquid fuels obtained from plants such as biofuels among which there may be mentioned vegetable oils, ethanol, butanol, ethyl tert-butyl ether (ETBE), methyl esters of fatty acids.

Compounds of Formula I can be prepared by palladio-catalyzed Suzuki coupling between a 1,3,5-trihaloarene optionally substituted at positions 2, 4 or 6 and three equivalents of an arylboronic acid in the presence of an inorganic base:

The compounds of Formula I not being substituted on the benzene ring A can also be prepared by cyclotrimerization of aryl methyl ketones according to:

The reaction takes place between 80 and 150 ° C in the presence of catalysts or dehydrating agents. The catalysts are Bronsted or Lewis acids. The use of arenesulfonic acids is well described in the literature. In particular the use of a catalytic amount of 4-toluenesulfonic acid monohydrate is described in Zhao, Y.; Li, J .; Li, C .; Yin, K .; Ye, D .; Jia, X. Green Chem. 2010, 12, 1370 .

The compound of Formula I is added to the fuel or liquid fuel in an amount of 0.01 to 500 mg / L, in particular in an amount of 0.02 to 20 mg / L, and more particularly in an amount of 0.1 to 5 mg / L.

A subject of the invention is also a process for marking fuels or liquid fuels, characterized in that a solution at 0.1 - 40% by weight of the compound of Formula I in a solvent or a mixture of solvents is prepared. and that said solution is injected into the fuel or liquid fuel, for example online in a pipeline or else at the loading arm of a tanker truck, or even in a tank to obtain the target concentration of the marker in the fuel or liquid fuel.

Preferably, a 0.2-20% by weight solution of the compound of Formula I in the solvent or mixture of solvents is prepared.

The solvent (s) can be chosen from aromatic solvents such as toluene, ethylbenzene, xylenes, mesitylene, 1,2,4-trimethylbenzene, cumene, p-cymene, aromatic hydrocarbons (for example Shellsol ® A100, Solvarex® 10, Solvesso® 200); from aliphatic solvents such as pentane, hexanes, cyclohexane, heptanes, 2,2,4-trimethylpentane, white spirits, kerosene, isoparaffins, paraffins; from oxygenated and / or nitrogenous solvents such as ketones, ethers, esters, lactones, phenols, amides, lactams; or from halogenated solvents such as chlorobenzene, 1,2-dichlorobenzene, α, α, α-trifluorotoluene.

The subject of the invention is also a method for determining whether fuels or liquid fuels have been adulterated by bleaching, characterized in that a sample of the fuel or liquid fuel which is suspected to have been adulterated is taken and that It is analyzed to determine whether the concentration of compound of Formula I in said sample is less than the initial concentration, and if so, it is inferred that the sample has been adulterated by bleaching.

The invention also relates to a method for determining whether fuels or liquid fuels have been adulterated by cutting, or have been used illegally or have been the subject of smuggling or theft, characterized in that one take a sample of fuel or liquid fuel suspected of having been adulterated or illegally used, smuggled or stolen, and analyzed to determine if the compound of Formula I is present in said sample, and, if so, it is inferred that the sample has been tampered with or used illegally or is the subject of smuggling or theft.

It can be emphasized here that the marker (s) according to the invention can be used individually or in combination with other markers.

Fuels or liquid fuels labeled with one or more compounds of Formula I can be analyzed qualitatively or quantitatively, for example, by the following methods: gas chromatography coupled to a flame ionization detector or to a mass spectrometer; high performance liquid chromatography coupled to a diode array detector or a mass spectrometer.

The following Examples illustrate the present invention without, however, limiting its scope. In these Examples, the percentages are by weight unless otherwise indicated.

The following tests for physical and chemical removal of the markers were carried out on the compounds of Examples 1 (reference), 2 to 18 (of the invention) and 19 and 20 (comparative).

Physical elimination test

In a test tube, to 10 mL of diesel fuel type B0 conforming to standard EN 590 containing 10 mg / L of chemical marker was added a quantity - specified in the rest of the text - of solid elimination agent: gel silica ¹ , activated carbon ² , alumina ³ .
¹ 0.060 - 0.200 mm, 40A, Acros 241660010
² Comelt Carbosorb 10A
³ Sigma-Aldrich 11028

The tube was shaken using a linear shaker at 300 strokes / min for 10 min.

• Colonne ZB-50 de 15 m x 0,25 mm x 0,25 µm ID.
• Hélium P = 90kPa
• Ecoulement de 50 mL/min.
• Injecteur 280°C
• Détecteur 300°C
• Four : 100°C à 320°C à 20°C/min puis 320°C pendant 19 min.
• Volume injecté : 2 µL.

The liquid was then filtered through a 0.2 µm polytetrafluoroethylene (PTFE) membrane and analyzed by GC / FID.

• ZB-50 column 15 mx 0.25 mm x 0.25 µm ID.
• Helium P = 90kPa
• Flow of 50 mL / min.
• 280 ° C injector
• 300 ° C detector
• Oven: 100 ° C to 320 ° C at 20 ° C / min then 320 ° C for 19 min.
• Volume injected: 2 µL.

Chemical elimination test

In a test tube, to 10 mL of diesel fuel type B0 conforming to standard EN 590 containing 10 mg / L of chemical marker was added 10 mL of chemical elimination agent: H ₂ SO ₄ , HNO ₃ , NaOH , NaClO, HCl at the concentrations indicated.

The tube was shaken using a linear shaker at 300 strokes / min for 10 min. After a few minutes of rest, the liquid constituting the phase upper was removed and then filtered through a 0.45 µm polytetrafluoroethylene (PTFE) membrane and analyzed by GC / FID. The analytical conditions are those indicated above for the physical elimination test.

Gas oil containing the compound of Examples 1 to 18 at a concentration of 10 mg / L was subjected to the physical and chemical elimination tests described above. The concentration of each compound, measured in the gas oil after the stripping treatment, is shown in Tables 1 to 18, respectively, as a percentage of the concentration measured before the stripping treatment.

Example 1 (reference) : 1,3,5-Tris (4-methylphenyl) benzene

A mixture of 134.2 g of 4'-methylacetophenone and 19 g of 4-toluenesulfonic acid monohydrate was heated to 140 ° C with stirring. The water was removed by distillation to reach the temperature and then during the course of the reaction. The temperature of 140 ° C was maintained for 24 h.

After the reaction mixture cooled to room temperature, toluene was added to dissolve the mass. The organic solution was then washed 3 times with water and then dried with magnesium sulfate. The solvent was removed by vacuum distillation.

92 g of 1,3,5-tris (4-methylphenyl) benzene were obtained. Purification by chromatography on silica gel (cyclohexane / ethyl acetate: 99/1) followed by recrystallization from ethanol gave a beige crystalline powder. <u> Table 1 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 68% 50% 20% 107%

Example 2 (of the invention) : 1,3,5-Tris (4-isobutylphenyl) benzene

The title compound was prepared according to the procedure of Example 1 except that the starting mixture was a mixture of 176.3 g of 4'-isobutylacetophenone and 19 g of 4-toluenesulfonic acid monohydrate.

126 g of a very viscous brown liquid containing 68% (m / m) of 1,3,5-tris (4-isobutylphenyl) benzene was obtained. <u> Table 2 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 19 H ₂ SO ₄ at 95% 65% HNO ₃ Alumina 5g 10% NaOH NaClO at 9.5% active chlorine 12% HCl 96% 88% 87% 101% 80% 119% 118% 91% 101%

Example 3 (of the invention) : 1,3,5-Tris (4-butylphenyl) benzene

The title compound was prepared according to the procedure of Example 1 except that the starting mixture was a mixture of 10 g of 4'-butylacetophenone and 1.1 g of 4-toluenesulfonic acid monohydrate.

10.1 g of 1,3,5-tris (4-butylphenyl) benzene was obtained as a very viscous brown liquid. <u> Table 3 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 65% HNO ₃ 100% 86% 63% 112% 83%

Example 4 (of the invention) : 1,3,5-Tris (4-tert-butylphenyl) benzene

1.23 g of 1,3,5-triphenylbenzene were suspended in 10 mL of dichloromethane and 1.5 mL of 2-chloro-2-methylpropane. 25 mg of ferric chloride were then added. After a few minutes, water and dichloromethane were added with stirring. The organic solution was then washed twice with 10% aqueous sodium carbonate solution, dried with magnesium sulfate and evaporated in vacuo. 1.88 g of 1,3,5-tris (4-tert-butylphenyl) benzene was obtained. A white crystalline product was obtained after recrystallization from toluene. <u> Table 4 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 96% 61% 99% 83%

Example 5 (of the invention) : 1,3,5-Tris (4-ethylphenyl) benzene

The title compound was prepared according to the procedure of Example 1 except that the starting mixture was a mixture of 10 g of 4'-ethylacetophenone and 1.3 g of 4-toluenesulfonic acid monohydrate.

7.3 g of 1,3,5-tris (4-ethylphenyl) benzene was obtained as a very viscous brown liquid. <u> Table 5 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 65% HNO ₃ 92% 48% 63% 111% 75%

Example 6 (of the invention) : 1,3,5-Tris (4-fluorophenyl) benzene

Under an argon atmosphere, a mixture of 630 mg of 1,3,5-tribromobenzene, 1.007 g of 4-fluorophenylboronic acid, 15 mg of palladium acetate and 52 mg of triphenylphosphine in 4 mL of aqueous solution of sodium carbonate. 2M sodium and 13 mL of 1-propanol was refluxed with stirring for 3 h.

20 mL of water was then added. The product was extracted twice with ethyl acetate. The organic solution was then washed with a 4% aqueous sodium bicarbonate solution and with saturated brine, dried over magnesium sulfate, filtered through Hyflo® and then evaporated in vacuo. The crude product was recrystallized from ethanol to give 0.53 g of 1,3,5-tris (4-fluorophenyl) benzene as a greyish-white crystalline powder. <u> Table 6 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 97% 67% 40% 102%

Example 7 (of the invention) : 1,3,5-Tris (4-chlorophenyl) benzene

1,3,5-tris (4-chlorophenyl) benzene was prepared according to the procedure of Example 1, replacing 4'-methylacetophenone with 4'-chloroacetophenone. The crude product was recrystallized from ethanol. 36.8 g of yellowish white crystals were obtained. <u> Table 7 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 65% HNO ₃ 88% 58% 9% 104% 100%

Example 8 (of the invention) : 1,3,5-Tris (4-bromophenyl) benzene

1,3,5-tris (4-bromophenyl) benzene was prepared according to the procedure of Example 1, replacing 4'-methylacetophenone with 4'-bromoacetophenone. The crude product was recrystallized from toluene. 54.3 g of yellowish white crystals were obtained. <u> Table 8 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 65% HNO ₃ 113% 85% 0% 122% 92%

Example 9 (of the invention) : 1-Dodecyloxy-2,4,6-tris (4-fluorophenyl) benzene

A mixture of 12.8 g of 2,4,6-tribromophenol, 9.85 g of 1-bromododecane and 10.35 g of potassium carbonate in 25 mL of N-ethylpyrrolidone was heated to 115 ° C under stirring for 2 h. The mixture was then poured into cold water. 16% hydrochloric acid was added until pH <2. The product was then extracted with cyclohexane. The organic solution was then washed with water, dried over potassium carbonate and then evaporated in vacuo to give 18.6 g of 1-dodecyloxy-2,4,6-tribromobenzene.

Under an argon atmosphere, a mixture of 998 mg of 1-dodecyloxy-2,4,6-tribromobenzene, 1.007 g of 4-fluorophenylboronic acid, 15 mg of palladium acetate and 52 mg of triphenylphosphine in 4 mL of solution aqueous 2M sodium carbonate and 13 mL of 1-propanol was heated to reflux temperature with stirring for 3 h.

20 mL of water was then added. The product was extracted twice with ethyl acetate. The organic solution was then washed with 4% aqueous sodium bicarbonate solution and with saturated brine, dried over magnesium sulfate, filtered through Hyflo® and evaporated in vacuo. The crude product was recrystallized from ethanol to give 0.69 g of 1-dodecyloxy-2,4,6-tris (4-fluorophenyl) benzene as a white crystalline powder. <u> Table 9 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 89% 60% 80% 103%

Example 10 (of the invention) : 1-Octyloxy-2,4,6-tris (4-fluorophenyl) benzene

1-Octyloxy-2,4,6-tribromobenzene was prepared following the procedure of Example 9 by replacing 1-bromododecane with 1-bromooctane.

Under an argon atmosphere, a mixture of 1.33 g of 1-octyloxy-2,4,6-tribromobenzene, 1.51 g of 4-fluorophenylboronic acid, 99 mg of palladium acetate and 297 mg of triphenylphosphine in 6 mL of 2M aqueous sodium carbonate solution and 20 mL of 1-propanol was refluxed with stirring for 2 h.

20 mL of water was then added. The product was extracted twice with ethyl acetate. The organic solution was then washed with 4% aqueous sodium bicarbonate solution and with saturated brine, dried over magnesium sulfate, filtered through Hyflo® and evaporated in vacuo. The crude product was recrystallized from ethanol to give 0.4 g of 1-octyloxy-2,4,6-tris (4-fluorophenyl) benzene as a white crystalline powder. <u> Table 10 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 88% 56% 83% 107%

Example 11 (of the invention) : 1-Butoxy-2,4,6-tris (4-fluorophenyl) benzene

1-Butoxy-2,4,6-tribromobenzene was prepared following the procedure of Example 9 by replacing 1-bromododecane with 1-bromobutane.

Under an argon atmosphere, a mixture of 774 mg of 1-butoxy-2,4,6-tribromobenzene, 1.007 g of 4-fluorophenylboronic acid, 15 mg of palladium acetate and 52 mg of triphenylphosphine in 4 mL of 2M aqueous sodium carbonate solution and 13 mL of 1-propanol was heated to reflux with stirring for 2 h.

20 mL of water was then added. The product was extracted twice with ethyl acetate. The organic solution was then washed with a 4% aqueous sodium bicarbonate solution and with saturated brine, dried over magnesium sulfate, filtered through Hyflo® and then evaporated in vacuo. The crude product was recrystallized from ethanol to give 0.52 g of 1-butoxy-2,4,6-tris (4-fluorophenyl) benzene as a white crystalline powder. <u> Table 11 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 96% 52% 103% 100%

Example 12 (of the invention) : 1-Dodecyloxy-2,4,6-tris (3,4-difluorophenyl) -benzene

Under an argon atmosphere, a mixture of 998 mg of 1-dodecyloxy-2,4,6-tribromobenzene (see Example 9), 1.14 g of 3,4-difluorophenylboronic acid, 66 mg of palladium acetate and 200 mg of triphenylphosphine in 4 mL of 2 M aqueous sodium carbonate solution and 13 mL of 1-propanol was refluxed with stirring for 2 h.

20 mL of water was then added. The product was extracted twice with ethyl acetate. The organic solution was then washed with a 4% aqueous sodium bicarbonate solution and with saturated brine, dried over magnesium sulfate, filtered through Hyflo® and then evaporated in vacuo. The crude product was recrystallized from ethanol to give 0.48 g of 1-dodecyloxy-2,4,6-tris (3,4-difluorophenyl) benzene as a white crystalline powder. <u> Table 12 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 93% 71% 64% 104%

Example 13 (of the invention) : 1-Octyloxy-2,4,6-tris (3,4 - difluorophenyl) -benzene

Under an argon atmosphere, a mixture of 886 mg of 1-octyloxy-2,4,6-tribromobenzene (see Example 10), 1.14 g of 3,4-difluorophenylboronic acid, 15 mg of palladium acetate and 52 mg of triphenylphosphine in 4 mL of 2 M aqueous sodium carbonate solution and 13 mL of 1-propanol was refluxed with stirring for 3 h.

20 mL of water was then added. The product was extracted twice with ethyl acetate. The organic solution was then washed with a 4% aqueous sodium bicarbonate solution and with saturated brine, dried over magnesium sulfate, filtered through Hyflo® and then evaporated in vacuo. The crude product was recrystallized from ethanol to give 0.83 g of 1-octyloxy-2,4,6-tris (3,4-difluorophenyl) benzene as a greyish crystalline powder. <u> Table 13 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 89% 62% 70% 100%

Example 14 (of the invention) : 1-Dodecyloxy-2,4,6-tris (4-methylphenyl) benzene

Under an argon atmosphere, a mixture of 998 mg of 1-dodecyloxy-2,4,6-tribromobenzene (see Example 9), 979 mg of 4-tolylboronic acid, 66 mg of palladium acetate and 199 mg of triphenylphosphine in 4 mL of 2M aqueous sodium carbonate solution and 14 mL of 1-propanol was refluxed with stirring for 4 h. 20 mL of water was then added. The product was extracted twice with ethyl acetate. The organic solution was then washed with a 4% aqueous sodium bicarbonate solution and with saturated brine, dried over magnesium sulfate, filtered through Hyflo® and then evaporated in vacuo. The crude product was recrystallized from ethanol to give 0.59 g of 1-octyloxy-2,4,6-tris (4-methylphenyl) benzene is obtained as a white crystalline powder. <u> Table 14 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 82% 47% 80% 108%

Example 15 (of the invention) : 1-Octyloxy-2,4,6-tris (4-methylphenyl) benzene

Under an argon atmosphere, a mixture of 886 mg of 1-octyloxy-2,4,6-tribromobenzene (see Example 10), 979 mg of 4-tolylboronic acid, 66 mg of palladium acetate and 199 mg of triphenylphosphine in 4 mL of 2M aqueous sodium carbonate solution and 14 mL of 1-propanol was refluxed with stirring for 2 h.

20 mL of water was then added. The product was extracted twice with ethyl acetate. The organic solution was then washed with a 4% aqueous sodium bicarbonate solution and with saturated brine, dried over magnesium sulfate, filtered through Hyflo® and then evaporated in vacuo. The crude product was recrystallized from ethanol to give 0.58 g of 1-octyloxy-2,4,6-tris (4-methylphenyl) benzene as a white crystalline powder. <u> Table 15 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 93% 53% 79% 103%

Example 16 (of the invention) : 1-Butoxy-2,4,6-tris (4-methylphenyl) benzene

Under an argon atmosphere, a mixture of 182 mg of 1-butoxy-2,4,6-tribromobenzene (see Example 11), 230 mg of 4-tolylboronic acid, 15 mg of palladium acetate and 47 mg of triphenylphosphine in 1 mL of 2M aqueous sodium carbonate solution and 3.5 mL of 1-propanol was refluxed with stirring for 2 h.

20 mL of water was then added. The product was extracted twice with ethyl acetate. The organic solution was then washed with a 4% aqueous sodium bicarbonate solution and with saturated brine, dried over magnesium sulfate, filtered through Hyflo® and then evaporated in vacuo. The crude product was recrystallized from ethanol to give 0.15 g of 1-octyloxy-2,4,6-tris (4-methylphenyl) benzene as a white crystalline powder. <u> Table 16 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 76% 34% 89% 108%

Example 17 (of the invention) -: 1-Dodecyloxy-2,4,6-tris (3-trifluoromethyl-phenyl) benzene

Under an argon atmosphere, a mixture of 998 mg of 1-dodecyloxy-2,4,6-tribromobenzene (see Example 9), 1.37 g of 3-trifluoromethylphenylboronic acid, 66 mg of palladium acetate and 199 mg of triphenylphosphine in 4 mL of 2 M aqueous sodium carbonate solution and 14 mL of 1-propanol was refluxed with stirring for 3 h.

20 mL of water was then added. The product was extracted twice with ethyl acetate. The organic solution was then washed with a 4% aqueous sodium bicarbonate solution and with saturated brine, dried over magnesium sulfate, filtered through Hyflo® and then evaporated in vacuo. 1.62 g of 1-dodecyloxy-2,4,6-tris (3-trifluoromethylphenyl) benzene in the form of a brownish oil. <u> Table 17 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 65% HNO ₃ 52% 53% 79% 73% 61%

Example 18 (of the invention) -: 1,3,5-Tris (2-methylphenyl) benzene

The product is marketed by Sigma-Aldrich (ref. 764671. <u> Table 18 </u> For 10 ml of marked diesel: Silica 0.5g Silica 2g Activated carbon 1g H ₂ SO ₄ at 95% 65% HNO ₃ 85% 58% 75% 98% 119%

Example 19 (comparative) : ((3- (sec-Butyl) -4- (decyloxy) phenyl) -methanetriyl) tribenzene

The patent application WO2014 / 008164 describes in particular ((3- (sec-butyl) -4- (decyloxy) phenyl) methane-triyl) tribenzene, sold under the name Accutrace S10®.

Gas oil containing ((3- (sec-butyl) -4- (decyloxy) phenyl) methanetriyl) tribenzene at a concentration of 10 mg / L was subjected to the physical and chemical elimination tests described above. The concentration of the compound measured in the gas oil after the stripping treatment is shown in Table 19 as the percentage of the concentration measured before the stripping treatment. <u> Table 19 </u> For 10 ml of marked diesel: Compound Silica 0.5g Silica 2g Activated carbon 1g Alumina 5g H ₂ SO ₄ at 95% 65% HNO ₃ 10% NaOH NaClO at 9.5% active chlorine 12% HCl Ex. 19 (Comp.) 82% 44 % 97% 99% 103% 0 100% 102% 99% Ex. 2 96% 88% 87% 119% 101% 80% 118% 91% 101%

The compound of Example 2 is markedly more resistant to treatment with silica than the compound of Comparative Example 19. On the other hand, the marker of Comparative Example 19 is completely removed by nitric acid while the compound of Example 2 shows very good resistance to this chemical agent.

Example 20 (comparative) : 1,3,5-Triphenylbenzene (TPB)

The product is marketed by Sigma-Aldrich (ref. T82007). Table 20 For 10 ml of marked diesel: Compound Silica 0.5g Silica 2g Activated carbon 1g Alumina 5g H ₂ SO ₄ at 95% 65% HNO ₃ 10% NaOH NaClO at 9.5% active chlorine 12% HCl Ex. 20 (Comp.) 81% 53% 29% 80% 103% 59% 100% 89% 99% Ex. 2 96% 88% 87% 119% 101% 80% 118% 91% 101%

The compound of Example 2 is significantly more resistant to treatment with activated carbon than TPB. In addition, the compound of Example 2 is superior to TPB for resistance to silica treatment.

Example 21 : Fuel injection nozzle clogging test according to CEC F-23-01

This test was carried out on type B0 gas oil conforming to standard EN 590 on the one hand without a marker and on the other hand with the marker of Example 2 added at a rate of 6.8 mg / L.

The average percentage reduction in airflow through the injector at 0.1 mm needle lift is 70.8 for non-marker fuel and 69.5 for marker fuel. The addition of the marker therefore has no significant influence on the fouling of the injection nozzles.

Claims (11)

1. Use as a tracer for marking liquid fuels and motor fuels of at least one compound of Formula I:

   

   where:

   - the benzene ring A is optionally substituted in at least one of the positions 2, 4 or 6 by:

   • a linear, branched or cyclic C₁-C₁₈ alkyl radical, optionally substituted by at least one halogen and/or optionally interrupted by at least one oxygen; or

   • a linear, branched or cyclic C₁-C₁₈ alkoxy radical, optionally substituted by at least one halogen and/or optionally interrupted by at least one oxygen; or

   • a linear, branched or cyclic C₂-C₁₈ alkenyl radical, optionally substituted by at least one halogen and/or optionally interrupted by at least one oxygen;

   - the benzene rings B, C and D are substituted, independently of one another, in at least one ortho, meta or para position relative to the benzene ring A by:

   • a linear, branched or cyclic C₁-C₁₈ alkyl radical, optionally substituted by at least one halogen and/or optionally interrupted by at least one oxygen; or

   • a linear, branched or cyclic C₁-C₁₈ alkoxy radical, optionally substituted by at least one halogen and/or optionally interrupted by at least one oxygen; or

   • a linear, branched or cyclic C₂-C₁₈ alkenyl radical, optionally substituted by at least one halogen and/or optionally interrupted by at least one oxygen; or

   • a halogen;

   at least one benzene ring B, C and D possibly comprising a 5 to 7-membered aliphatic ring fused thereto,
   provided that, when the benzene ring A is not substituted and the benzene rings B, C and D are each substituted by a methyl, the latter is not at para position relative to the benzene ring A.
2. The use according to claim 1, characterized by the fact that the benzene ring A is non-substituted or substituted by C₁-C₁₈ alkoxy.
3. The use according to one of claims 1 or 2, characterized by the fact that the benzene rings B, C and D are substituted by:

   - a linear, branched or cyclic C₁-C₁₈ alkyl radical, in particular C₁-C₁₂, more particularly C₁-C₆, optionally substituted by at least one halogen; or

   - at least one halogen.
4. The use according to one of claims 1 to 3, characterized by the fact that a halogen included in the definition of Formula I is F, Cl, Br and I, and in particular F, Cl and Br.
5. The use according to one of claims 1 to 4, characterized by the fact that the Formula I compound is selected from among:

   

   

   

   

   

   

   

   

   in particular:

   
6. Liquid fuel or motor fuel containing at least one Formula I compound such as defined in one of claims 1 to 5, characterized by the fact that the Formula I compound is added to the liquid fuel or motor fuel in a proportion of 0.01 to 500 mg/L, particularly in a proportion of 0.02 to 20 mg/L, and more particularly in a proportion of 0.1 to 5 mg/L.
7. A method for marking liquid fuels or motor fuels, characterized by the fact that a solution is prepared of 0.1 - 40 weight % of the Formula I compound such as defined in one of claims 1 to 5, in a solvent or mixture of solvents, and said solution is injected into the liquid fuel or motor fuel for example in-line into a pipeline or else into a loading arm of a tanker, or else into a tank to obtain the targeted concentration of the marker in the liquid fuel or motor fuel.
8. The method according to claim 7, characterized by the fact that a solution is prepared of 0.2 to 20 weight % of the Formula I compound in the solvent or mixture of solvents.
9. The method according to one of claims 7 and 8, characterized by the fact that the solvent(s) are selected from among aromatic solvents such as toluene, ethylbenzene, xylenes, mesitylene, 1.2.4-trimethylbenzene, cumene, p-cymene, aromatic hydrocarbons (e.g. Shellsol® A100, Solvarex® 10, Solvesso® 200); from among aliphatic solvents such as pentane, hexanes, cyclohexane, heptanes, 2,2,4-trimethylpentane, white spirits, kerosene, isoparaffins, paraffins; from among oxygen- and/or nitrogen-containing solvents such as ketones, ethers, esters, lactones, phenols, amides, lactams; or from among halogenated solvents such as chlorobenzene, 1,2-dichlorobenzene, α,α,α-trifluorotoluene.
10. A method for determining whether liquid fuels or motor fuels have been tampered with by laundering, characterized by the fact that a sample is taken of the suspected tampered liquid fuel or motor fuel and it is analysed to determine whether the concentration of Formula I compound such as defined in one of claims 1 to 5 in said sample is less than the initial concentration, and in the affirmative it is inferred that the sample has been tampered with by laundering.
11. A method for determining whether liquid fuels or motor fuels have been tampered with by diluting, or have been used illegally, or have been the subject of smuggling or theft, characterized by the fact that a sample is taken of the liquid fuel or motor fuel suspected of having been tampered with or used illegally or of being the subject of smuggling or theft, and it is analysed to determine whether the Formula I compound such as defined in one of claims 1 to 5 is contained in said sample, and in the affirmative it is inferred that the sample has been tampered with or used illegally or is the subject of smuggling or theft.