DE2359100A1 - PROCESS FOR THE PRODUCTION OF UNSATATULATED HYDROCARBONS - Google Patents

Description

MM 2 Nov 7, 1973

Dr. ί pit ζ I eder / tf

PATENT Attorney *

6510/103

L. Givaudan & Cie Societe Anonyme, Vernier-Geneve (Switzerland)

Process for the production of unsaturated hydrocarbons

The invention relates to a process for the preparation of unsaturated hydrocarbons of the formula

R ¹ R ² R ³ R ⁴

Il Il

CH ₂ = C - C = CH - CH ₂ - CH - C = CH ₂ (I)

in which R and R are hydrogen, lower-alkyl,

2 lower-alkenyl or lower-alkoxy and R and · χ.

R is hydrogen, lower-alkyl or lower-alkenyl mean,

with the proviso that only one of the radicals R or R is hydrogen or lower-alkoxy ». *

The method according to the invention is characterized in that that you can get a compound of the formula

409824/1128

ORIGINAL IN8PSSTED

¹¹ R ²

CH ₂ = CC = CH ₂ (II)

in which R is lower-alkyl or lower-alkenyl

and R mean the same as above,

or a mixture of a compound of the formula (II) and a compound of the formula

^4th
CH ₂ = C - C = CH ₂ (III)

in which R and R mean the same as above, or a G-emiseh. of butadiene and a compound of the formula

CH ₂ = C -CH = CH ₂ (IV)

12th

in which R is lower alkoxy,

with. Pd (II) salts or coordinated Pd (II) complexes treated .

The term "lower" used here relates to groups with up to 7 carbon atoms. Examples of lower alkyl groups are methyl, ethyl, propyl, butyl and isomers. A preferred alkenyl group is 4-methyl-penten-3-yl.

The compounds obtainable according to the invention can be used as fragrances or as intermediates for the production of fragrances. The compounds of the formula (I) in which R or R are lower-alkoxy
also the subject of the invention.

(I) in which R or R represents lower alkoxy are new and

In the German Offenlegungsschrift 2150355

409824/1 128

Preparation of alky! Substituted 1,3 »7-oetatrienes alkyl-substituted 1,3-butadlaien by means of dienophile-coordinated Palladium (O) phosphine complexes, especially bis (triphenylphosphine) maleic anhydride palladium, Such dienophile-coordinated catalysts are relatively expensive and cumbersome and can only be reused after extensive work-up. The present invention avoids these Disadvantage.

The process according to the invention can be carried out in the presence or in the absence of a solvent. as Particularly suitable solvents are those which are inert towards the starting materials and end products and in which the catalyst at least partially dissolves. Examples of such solvents are linear and cyclic Ethers such as diethyl ether, tetrahydrofuran and dioxane; Alcohols such as methanol, ethanol. Propanol; Ketones such as acetone, acid amides such as dimethylformamide; Nitriles such as acetonitrile; Pyridine and homologues; aliphatic hydrocarbons such as hexane, aromatic hydrocarbons such as benzene and toluene; Olefins, Esters, sulfones and phosphoric acid amides. aliphatic carboxylic acids such as acetic acid or propionic acid.

Examples of palladium (II) salts which can be used in the process according to the invention are palladium (II) nitrate, palladium (II) acetate, palladium (II) chloride, bis (triphenylphosphine palladium dichloride, bis - (Triphenylphosphine) palladium (II) nitrate, K ₃ PdGl. And palladium (II) acetylacetonate. The coordinated palladium (II) complexes used according to the invention can contain ligands such as trialkylphosphines, for example tricyclohexylphosphine or tributylphosphine, triarykphosphines such as triphenylphosphines, trialhenylphosphines such as triethyl phosphite and triaryl phosphite such as triphenyl phosphite The complex compounds can also be prepared in situ in the reaction mixture

4 09824/1128

Add excess of the ligands contained in the complex. Phosphorus compounds can also be used as ligands, in which the phosphorus is bound to both oxygen and carbon, such as phenyl-di-n-butoxyphosphine. Even Water and carbon dioxide together or alone can be used as ligands and particularly improve the yields in aprotic solvents. The amount of ligand added is not critical, but it is advantageously between O and 20 moles based on 1 mole of palladium catalyst. Using of carbon dioxide and water, however, this proportion can be considerably exceeded. There can be amounts of 1000 mol and more can be used for 1 mol of palladium catalyst. The amount of catalyst added is not critical, preferably $ 0.01 to $ 10 catalyst, based on the ' Dien, used. In a preferred embodiment leads the inventive reaction in the presence of protons by, which can be supplied by the solvent or the catalyst or the ligands. When using palladium chlorides As a catalyst, it is advantageous to add a base, for example sodium carbonate, to the reaction mixture in order to To bind hydrogen chloride.

The reaction according to the invention can be carried out, for example, at temperatures between 20 and 200 ^° C., preferably between 80 and 150 ^° C. The reaction can be carried out in a pressure vessel under autogenous pressure, but also at elevated pressure or at atmospheric pressure.

The following examples illustrate the invention.

409824/1128

example 1

A 300 ml autoclave was charged with 68 g isoprene, 100 ml dioxane, 5 ml water, Ig palladium acetylacetonate and 4.3 g triphenylphosphine. After 24 hours of heating at 90-100 ⁰ C under autogenous pressure and good stirring was cooled and the reaction mixture at 30-4O ⁰ C and 0.1 mmHg completely distilled off from the catalyst. Removal of the excess isoprene and the solvent gave 62 g of a colorless oil which, according to gas chromatographic analysis, consisted of 83% 2,7-dimethyl-1,3,7-octatriene and 12% cyclic dimers of isoprene. Fractional distillation gave the 2,7-dimethyl

20 1,3,7-octatriene pure at 55 ⁰ C and 10 mmHg (η _β 1.4742) .. The

The catalyst can be removed by recrystallization from acetone / ethyl acetate regain in active form.

Example 2

20.5 g of 2,3-dimethyl-1,3-butadiene were reacted analogously to Example 1 for 48 hours. Could be the work-up gave 16.5 g of a ÖIS, from the 2,3,6,7-tetramethyl-l, 3,7-octatriene by fractional distillation at 60-80 ⁰ C and 10 mmHg at a 50 cm spinning band column purely won .

Example 3

54 g of isoprene were reacted with 27 g of myrcene as in Example 1. During work-up, the reaction mixture could be broken down _{into its C 10} , C 1, and C _{2Q components by distillation.} The C ₁₀ portion (34 g) consisted of 2,7-dimethyl-1,3,7-octatriene

and little unreacted myrcene. The C _n [portion (24 g, bp.

20th
75-80 ° C / 0.15 mmHg; n ^ 1, 4892) was composed of two codimers of myrcene and isoprene in a ratio of 60:40, which could be separated by preparative gas chromatography. To the

409824/1128

Due to its physical spectra, the main product had to have the structure of a 2, ll-dimethyl-7-methylene-l, 5,10-dodecatriene

Cn _n 1.4885), while the second isomer is a

?O

2, ll-dimethyl-7-methylene-1,3,10-dodecatriene (nJJ 1,4903) represented. Cp from the _O moiety could finally 7 g 2,15-dimethyl-6, ll-dimethylene-2,7,14-hexadecatrien (bp. 123 ° C / O, O1 20

mmHg; η _β 1.4970) can be isolated and clearly identified by spectroscopy.

Example 4

1 g of Pd (NO,) _? . 2H _? 0.5 g of triphenylphosphine, 100 ml of isopropanol and 27 g of myrcene were added. The autoclave was sealed, cooled to -80 ⁰ C and evacuated. Then "52 g of butadiene were condensed into the autoclave and the mixture under autogenous pressure heated 48 hours at 100 ⁰ C. Once opened, the solvent and the volatile reaction products were then (Butadiendimere and unreacted myrcene)" at 100 mmHg and 50 ⁰ C removed . Distillation of the residue at 55-65 ° C / 0.01 mmHg gave 41 g of a colorless oil, 64 $ from the codimers II-methyl-7-methylene-l, 3,10-dodecatriene and H-methy1-7- methylene-1,5,10-dodecatriene in a ratio of 60:40. Both isomers could be isolated in pure form by preparative gas chromatography. The physical spectra are consistent with the structures.

Example 5

In a 300 ml autoclave, 30 g of 2-ethoxybutadiene, 68 g of isoprene, 100 ml of dioxane, 1 g of palladium acetyl acetonate and 4.3 g of triphenylphosphine and heated to 100 ° C. for 48 hours heated. After this time, the mixture was cooled and the volatile components were drawn off at 30.degree. C. and 10 mmHg. Fractional distillation the residue gave 38 g of 2,7-dimethyl-1,3 »7-octatriene

409824/1128

and 27 g of two co-dimers of isoprene and 2-Aethoxybutadien in the ratio 1: 4 at 83 ⁰ C and 10 mmHg. From the physical spectra, the structure of a 2-methyl-7-ethoxy-1,3,7-octatriene could be assigned to the main products, while the isomer consisted of a 2-ethoxy-7-methyl-1,3 »7-octatriene . Saponification with 2N HCl gave "the expected ketones.

Example 6

In a 500 ml two-necked flask, 100 g of Myreen, 30 g of 2-ethoxybutadiene, 150 ml of dioxane, 1 g of palladium acetylacetonate and 4.3 g of triphenylphosphine were refluxed for 48 hours. Subsequently, at 50 ⁰ C and 10 mmHg peeled off the volatiles and the residue at 0.01 mmHg over a 20 cm Vigreux column fractionated. At 96 ° C./0.0l nmHg, 47 g of a fraction could be isolated which, according to its gas chromatographic analysis, consisted of 76% of 2-ethoxy-7-methylene-11-methyl-1,5,10-dodecatriene and 2-ethoxy -7-methylen-ll-methyl-1,3 »10-dodecatriene in the ratio 9il consisted. The codimers were obtained in pure form by renewed distillation at 72 ° C./0.01 mmHg in a 30 cm Eischer canned column. Saponification with 2N HCl gave the expected ketones. 13 g of the myrcendxmer already described could also be isolated.

Example 7

In analogy to Examples 5 and 6, 2-ethoxy-1,3,7-octatriene was obtained by dimerizing 2-ethoxybutadiene and butadiene and 2-ethoxy-1,5,7-octatriene obtained.

0-9824 / 1 128

Claims (9)

Claims 1. Process for the preparation of compounds of the formula R ¹ R ² R ⁵ R ⁴ ff ff UxI ₀ OO Uti OxIp O Xl- U UXi ₀ ^ J. ^ 1 4
in which R and R are hydrogen, lower-alkyl, lower-alkenyl or lower-alkoxy and R and R is hydrogen, lower-alkyl or lower-alkenyl, with the proviso that only one of the radicals R or R is hydrogen or lower-alkoxy, characterized in that one is a compound of the formula R ¹¹ f
CH ₂ = CC = CH ₂ (II) in which R is lower-alkyl or lower-alkenyl 2
and R mean the same as above, or a mixture of a compound of the formula (II) and a compound of the formula r3 _R 4
Xt CH ₂ = C - 6 = CH ₂ (III) 3 4 in which R and R mean the same as above, or a mixture of butadiene and a compound of the formula. CH = C - CH = CH ₂ (IV) 12th in which R is lower alkoxy, with Pd (II) salts or coordinated Pd (II) complexes treated. 40982 A / 1128 2. The method according to claim 1, characterized in that that one uses complexes of Pd (II) with organophosphorus compounds. 3. Process according to Claims 1 and 2, characterized in that the palladium (II) compound is palladium acetylacetonate. or palladium (II) nitrate is used. 4. The method according to claims 1-3, characterized in that the reaction medium contains protons. 5. Process according to claims 1-4, characterized in that the starting material used is a mixture of a compound of the formula (III) in which R represents lower alkoxy, and a compound of the formula (II) is used. 6. The method according to claim 5, characterized in that the compound of formula (III) is 2-ethoxybutadiene used. 409824/1 128 7. Compounds of the formula R ¹ R ² R ⁵ R ⁴ CHf = C C = CH CH ₂ CH - C = CH ₂ (I) in which R and R are hydrogen, lower-alkyl, lower-alkenyl or lower-alkoxy and R and R is hydrogen, lower-alkyl or lower-alkenyl mean, with the proviso that a radical R or R is lower-alkoxy. 8. 2-ethoxy-1,3,7-octatriene, 9.2 ~ ethoxy-l, 5.7-octatricn. 409824/1128