Method for the production of 2,7-octadienyl derivatives
View Patent ↗Process for preparing 1-octa-2,7-dienyl derivatives by reacting a 1,3-butadiene-containing hydrocarbon mixture, in particular a C 4 fraction from a cracker, with nucleophiles, in which acetylenically unsaturated compounds are removed from the starting hydrocarbon mixture by selective hydrogenation and a telomerization is subsequently carried out.
1. A process for preparing a compound of the formula I
in which X is an OR 1a or NR 1a R 1b radical, where R 1a and R 1b are selected independently from among hydrogen, a linear, branched or cyclic C 1 C- 22 -alkyl group, an alkenyl group, an alkynyl group, a C 5 -C 18 -aryl group or a —CO-alkyl-(C 1 -C 8 ) group or a —CO-aryl-(C 5 -C 10 ) group, with these groups being able to contain substituents selected or the group consisting of —CN, —COOH, —COO-alkyl-(C 1 -C 8 ), —CO-alkyl-(C 1 -C 8 ), -aryl-(C 5 -C 10 ), —COO-aryl-(C 6 -C 10 ), —CO-aryl-(C 6 -C 10 ), —O-alkyl-(C 1 -C 8 ), —O—CO-alkyl-(C 1 -C 8 ), —N-alkyl 2 -(C 1 C 8 ), —CHO, —SO 3 H, —NH 2 , —F, —Cl, —OH, —CF 3 , —NO 2 and the radicals R 1a and R 1b being able to be joined to one another via covalent bonds, from a 1,3-butadiene-containing hydrocarbon stream comprising allenically unsaturated compounds and more than 100 ppm by mass of acetylenically unsaturated compounds, in which process the acetylenically unsaturated compounds are removed in a first process step and 1,3-butadiene is reacted with a nucleophile in the presence of a metal compound in a second process step (telomerization step), wherein the hydrocarbon stream which is obtained from the first process step and is used as starting material in the second process step has a content of acetylenically unsaturated compounds of less than or equal to 100 ppm by mass and a content of allenically unsaturated compounds which is at least 75% (relative) of the original content of allenically unsaturated compounds.
2. The process as claimed in claim 1 , wherein a compound of the formula IIA or IIB,
is prepared by reacting 1,3-butadiene with a nucleophile of the formula III, IV or V
R 1a —O—H (III)
(R 1a )(R 1b )N—H (IV)
R 1a —COOH (V)
where R 1a and R 1b are as defined in claim 1 .
3. The process as claimed in claim 1 , wherein a C 4 -hydrocarbon fraction is used as hydrocarbon stream.
4. The process as claimed in claim 1 , wherein the acetylenically unsaturated compounds are separated by extraction.
5. The process as claimed in claim 1 , wherein acetylenically unsaturated compounds are removed by hydrogenation.
6. The process as claimed in claim 5 , wherein a copper-containing catalyst is used in the hydrogenation.
7. The process as claimed in claim 5 , wherein a palladium-containing catalyst is used in the hydrogenation.
8. The process as claimed in claim 5 , wherein compounds having more than 4 or 5 carbon atoms are separated from the hydrocarbon stream obtained as hydrogenation product mixture from the first process step before it is fed to the second process step (telomerization).
9. The process as claimed in claim 1 , wherein the hydrocarbon stream obtained as process product from the first process step is used directly as starting material in the second process step.
10. The process as claimed in claim 1 , wherein the hydrocarbon stream obtained as process product from the first process step is mixed with a 1,3-butadiene stream from a butadiene plant and this mixture is used in the second process step.
11. The process as claimed in claim 1 , wherein the content of acetylenically unsaturated compounds in the hydrocarbon mixture which is fed to the telomerization step is less than 50 ppm by mass.
12. The process as claimed in claim 11 , wherein the content of acetylenically unsaturated compounds in the hydrocarbon mixture which is fed to the telomerization step is less than 20 ppm by mass.
13. The process as claimed in claim 1 , wherein the nucleophile used in the second process step is methanol, ethanol, 2-ethylhexanol, octanol, octenol, octadienol, isopropanol, n-propanol, isobutanol, n-butanol, isononanol, formic acid, acetic acid, propionic acid, n-butanoic acid, iso-butanoic acid, benzoic acid, phthalic acid, phenol, dimethylamine, methylamine, ammonia or water.
14. The process as claimed in claim 1 , wherein a metal-carbene complex is used as telomerization catalyst in the second process step.
15. The process as claimed in claim 14 , wherein a palladium-carbene complex is used as telomerization catalyst n the second process step.
16. The process as claimed in claim 1 , wherein the allenically unsaturated compounds are separated from the telomerization product mixture by distillation.
17. The process as claimed in claim 1 , wherein a C 4 fraction is separated from the output from the second process step and dienes are removed from the treated output by selective hydrogenation.
18. The process as claimed in claim 17 , wherein the hydrogenated C 4 fraction is worked-up like raffinate I.
19. The process as claimed in claim 1 , wherein X in the formula I is OR 1a or NR 1a R 1b , where
R 1a H, methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-butyl, sec-butyl, pentyl, hexyl, heptyl, octyl, octenyl, octadienyl, isononyl, 2-ethylhexyl, n-nonyl, phenyl, m-, o- or p-methylphenyl, naphthyl, 2,4-di-tert-butylphenyl, 2,6-di-ter-butylmethylphenyl, hydrogencarbonyl, methyl-carbonyl, ethylcarbonyl, propylcarbonyl or phenylcarbonyl and
R 1b is H, methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-butyl, sec-butyl, pentyl, hexyl, heptyl, octyl, octenyl, octadienyl, isononyl, 2-ethylhexyl, n-nonyl, phenyl, m-, o- or p-methylphenyl, naphthyl, 2,4-di-tert-butylphenyl, 2,6-di-tert-butylmethylphenyl, hydrogencarbonyl, methyl-carbonyl, ethylcarbonyl, propylcarbonyl or phenylcarbonyl.