BRANCHED ALKANES AND PROCESS FOR PREPARING SAME

Abstract

The present application relates to branched alkanes comprising n carbon atoms, n being an integer between 9 and 50, to the process for preparing same and to uses thereof. The present application also relates to the olefins for obtaining these branched alkanes.

Claims

1. A branched alkane of the following formula (I): ##STR00021## R.sup.1, R.sup.2, R.sup.3 and R.sup.4, identical or different, are selected from H, alkyls, linear or branched, comprising 1 to 46 carbon atoms and the total number of carbon atoms in all the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 groups being between 7 and 48; provided that: at most two of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 groups are H one of the R.sup.1, R.sup.2, R.sup.3 or R.sup.4 groups includes or is a tert-butyl group.

2. The branched alkane according to claim 1, with one of R.sup.1, R.sup.2, R.sup.3 or R.sup.4 representing a methyl group.

3. A mixture comprising at least two branched alkanes according to claim 1, for which the n carbon atoms are identical or different.

4. The mixture according to claim 3, free from aromatic compounds.

5. A branched olefin of formula (III) ##STR00022## R.sup.1, R.sup.2, R.sup.3 and R.sup.4, identical or different, are selected from H, alkyls, linear or branched, comprising 1 to 46 carbon atoms and the total number of carbon atoms in all the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 groups being between 7 and 48; provided that: at most two of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 groups are H one of the R.sup.2, R.sup.2, R.sup.3 or R.sup.4 groups includes or is a tert-butyl group.

6. A mixture comprising at least two branched olefins according to claim 5, the n carbon atoms are identical or different.

7. A method for obtaining a branched alkane according to claim 1 or of a mixture comprising at least two of the branched alkanes, comprising a step of dehydrogenation of a branched olefin of formula (III) ##STR00023## R.sup.1, R.sup.2, R.sup.3 and R.sup.4, identical or different, are selected from H, alkyls, linear or branched, comprising 1 to 46 carbon atoms and the total number of carbon atoms in all the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 groups being between 7 and 48; provided that: at most two of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 groups are H one of the R.sup.1, R.sup.2, R.sup.3 or R.sup.4 groups includes or is a tert-butyl group or a mixture comprising at least two of the branched olefins.

8. The method according to claim 7, wherein the branched olefin or the mixture is obtained by dimerisation of a mixture of branched olefin isomers comprising n/2 carbon atoms when n represents 16, 24, 32, 40 or 48, by codimerisation or by metathesis of lower olefins.

9. The method according to claim 8, wherein the branched olefin mixture comprising n/2 carbon atoms is obtained from bioresources.

10. The method according to claim 8, wherein the dimerisation step is implemented in the presence of a catalyst selected from Brönsted acids in solution; solid Brönsted acids; Lewis acids; organometallic compounds; ionic liquids; clays with lamellar structures; organometallic compounds.

11. The method according to claim 8, wherein the codimerisation method is implemented with lower olefins of formulae (IV) and (V):
R.sup.5R.sup.6C═CR.sup.7R.sup.8  (IV)
R.sup.9R.sup.10C═CR.sup.11R.sup.12  (V) the olefin (IV) being an exo olefin (terminal double bond) or endo olefin (non-terminal double bond) comprising m carbon atoms, the olefin (V) comprising p carbon atoms, with m+p=n with n representing an integer between 9 and 50, m between 4 and 32 and p between 3 and 46, thus, in the formulae (IV) and (V) R.sup.7 and R.sup.8 represent H and R.sup.5 and R.sup.6, identical or different, represent an alkyl group, linear or branched, comprising in total, with the carbon atoms carrying the double bond, m carbon atoms; or R.sup.5, R.sup.6, R.sup.7 and R.sup.8, identical or different, represent a linear or branched alkyl group comprising in total, with the carbon atoms carrying the double bond, m carbon atoms; or R.sup.5 represents H and R.sup.6, R.sup.7 and R.sup.8, identical or different, represent a linear or branched alkyl group comprising in total, with the carbon atoms carrying the double bond, m carbon atoms; R.sup.9, R.sup.10, R.sup.11 and R.sup.12, identical or different, represent an alkyl group, linear or branched, comprising in total, with the carbon atoms carrying the double bond, p carbon atoms; or R.sup.9, R.sup.11 and R.sup.12 represent H and R.sup.10 represents an alkyl group, linear or branched, comprising in total, with the carbon atoms carrying the double bond, p carbon atoms.

12. The method according to claim 8, wherein the metathesis method is implemented with lower olefins of formulae (VI) and (VII):
R.sup.13R.sup.14C═CR.sup.15R.sup.16  (VI)
R.sup.17R.sup.18C═CR.sup.19R.sup.20  (VII) the olefin (VI) being an exo olefin (terminal double bond) or endo olefin (non-terminal double bond) comprising q carbon atoms; the olefin (VII) comprising r carbon atoms, q is between 4 and 32 and r is between 3 and 40; thus, in the formulae (VI) and (VII) R.sup.15 and R.sup.16 represent H and R.sup.13 and R.sup.14, identical or different, represent an alkyl group, linear or branched, comprising in total, with the carbon atoms carrying the double bond, q carbon atoms; or R.sup.13, R.sup.14, R.sup.15 and R.sup.16, identical or different, represent an alkyl group, linear or branched, comprising in total, with the carbon atoms carrying the double bond, q carbon atoms; or R.sup.13 represents H and R.sup.14, R.sup.15 and R.sup.16, identical or different, represent an alkyl group, linear or branched, comprising in total, with the carbon atoms carrying the double bond, q carbon atoms; R.sup.17, R.sup.18, R.sup.19 and R.sup.20, identical or different, represent an alkyl group, linear or branched, comprising in total, with the carbon atoms carrying the double bond, q carbon atoms; or R.sup.17, R.sup.19 and R.sup.20 represent H and R.sup.18 represents an alkyl group, linear or branched, comprising a total, with the carbon atoms carrying the double bond, r carbon atoms.

13. The method according to claim 9, wherein the codimerisation step is implemented in the presence of a catalyst selected from Brönsted acids in solution; solid Brönsted acids; Lewis acids; ionic liquids; clays with lamellar structures; organometallic compounds.

14. The method according to claim 10, wherein the metathesis step is implemented by reacting the two olefins in the presence of a metathesis catalyst.

15. A method for formulating a cosmetic composition, a plasticising composition or a lubricating composition comprising including an alkane according to claim 1 or mixture comprising at least two of the branched alkanes.

16. A mixture comprising at least two branched alkanes according to claim 2, for which the n carbon atoms are identical or different.

17. The mixture according to claim 16, free from aromatic compounds.

18. A method for obtaining a branched alkane according to claim 2 or of a mixture comprising at least two of the branched alkanes, comprising a step of dehydrogenation of a branched olefin of formula (III) ##STR00024## R.sup.1, R.sup.2, R.sup.3 and R.sup.4, identical or different, are selected from H, alkyls, linear or branched, comprising 1 to 46 carbon atoms and the total number of carbon atoms in all the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 groups being between 7 and 48; provided that: at most two of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 groups are H one of the R.sup.1, R.sup.2, R.sup.3 or R.sup.4 groups includes or is a tert-butyl group or a mixture comprising at least two of the branched olefins.

19. The method according to claim 9, wherein the dimerisation step is implemented in the presence of a catalyst selected from Brönsted acids in solution; solid Brönsted acids; Lewis acids; organometallic compounds; ionic liquids; clays with lamellar structures; and organometallic compound.

20. The method according to claim 10, wherein the metathesis step is implemented by reacting the two olefins in the presence of a metathesis catalyst selected from the 2.sup.nd generation Grubbs catalyst.

Description

EXAMPLE 1: DIMERISATION OF ISOOCTENE

[0163] The following are loaded into a stirred autoclave, closed and put under inert atmosphere: [0164] 100 g of isooctene [0165] 10 g of Montmorillonite [0166] 5 g of isooctane

[0167] Heating is carried out gradually and dimerisation commences at around 150° C.

[0168] The temperature is continued to be increased up to 200° C.

[0169] The mixture is maintained under stirring and at this level temperature for 3 hours.

[0170] The reaction mixture is cooled to ambient temperature.

[0171] The Montmorillonite catalyst is separated from the liquid phase by filtration.

[0172] The liquid phase is diluted in a cyclohexane solvent for analysis requirements.

[0173] The conversion of isooctane is between 70 and 95%. The yields of dimerisation products of isooctane (hexaisododecenes) are between 50 and 90%.

EXAMPLE 2: DIMERISATION OF ISOOCTENE

[0174] The catalyst used in this example is sold by AXEN and is a solution of dichloroalkylaluminium at 50% by weight in a C.sub.6-C.sub.8 paraffinic petroleum fraction, and nickel-based liquid catalyst.

[0175] The following are loaded into a stirred autoclave closed and put under inert atmosphere: [0176] 100 g of isooctene [0177] 0.45 g of the catalytic solution defined above

[0178] The reaction mixture is maintained at between 45 and 50° C. for 2 hours.

[0179] The mixture is cooled to ambient temperature.

[0180] The mixture is treated by a basic aqueous solution of sodium carbonate or of soda and the organic and aqueous phases are next separated by settling.

[0181] The organic phase is analysed.

[0182] The conversion of the isooctane is between 70 and 100%.

[0183] The yields of dimerisation products of the isooctane (hexaisododecenes) are between 60 and 90%.

EXAMPLE 3: HYDROGENATION OF THE COMPOUNDS RESULTING FROM EXAMPLES 1 AND 2

[0184] After 3 purges under nitrogen stream, the following are loaded into a hydrogenation reactor (stirring and maintenance under pressure): [0185] 100 g of dimer of the isooctane obtained at examples 1 and 2 [0186] 5 g of Raney Ni catalyst [0187] 50 g of isooctane.

[0188] The stirred mixture is heated to a temperature of 80° C.

[0189] Hydrogen is introduced while adjusting the pressure to a constant value of 20 atmospheres.

[0190] The reaction mixture is kept stirred, at 50° C., under constant pressure of hydrogen for a period of 3 hours.

[0191] At the end of the reaction, the excess hydrogen is eliminated by pressure reduction and the top of the reactor is purged 3 times with nitrogen.

[0192] The reaction medium is diluted in cyclohexane for analytical purposes.

[0193] The reaction medium is analysed:

[0194] The conversion of dimer of the isooctane is 100%.

[0195] The yield of hydrogenated dimer (branched alkane according to the invention) is 100%.

EXAMPLE 4: METATHESIS OF ISOOCTANE AND OCTENE]

[0196] The following are added successively in a Schlenk flask: 18.5 mmol of isooctene (2.1 mL) 4 mmol of octene (0.45 mL) and (1,3-dimesitylimidazolidine-2-ylidene)(tricyclohexylphosphine)benzylidene ruthenium dichloride (68 mg, 0.08 mmol). The solution is heated to 55° C. and regularly degassed. After 40 h, 0.3 mL of ethyl vinyl ether is added. The product is dissolved in toluene (50 mL) and then filtered on neutral alumina. 42% of product (C.sub.14 olefin) is obtained after the solvent is evaporated.

[0197] An identical method can be implemented for the following reactions:

##STR00018##

EXAMPLE 5: CODIMERISATION

[0198] The following are loaded into a stirred autoclave, closed and put under inert atmosphere: [0199] 100 g of isooctene [0200] 100 g of n-octene [0201] 10 g of Montmorillonite [0202] 5 g of isooctane

[0203] Heating is carried out gradually and codimerisation commences at around 150° C.

[0204] The temperature is continued to be increased up to 200° C.

[0205] The mixture is maintained under stirring and at this level temperature for 3 hours.

[0206] The reaction mixture is cooled to ambient temperature.

[0207] The Montmorillonite catalyst is separated from the liquid phase by filtration. The liquid phase is diluted in a cyclohexane solvent for the requirements of analysis.

[0208] The conversion is between 70 and 95%. The yields of hexadodecene and products of the codimerisation of isooctane with n octene are between 50 and 90%.

[0209] An identical method can be implemented for the following reactions:

##STR00019##

EXAMPLE 6: OBTAINING C.SUB.12 .OLEFINS

[0210] The methods of the invention (codimerisation and metathesis) can be implemented to obtain olefins comprising 12 carbon atoms, in accordance for example with the following reaction diagrams:

##STR00020##