DE2533399A1 - PROCESS FOR MANUFACTURING ALIPHATIC ALPHA, BETA UNSATATULATED NITRILE - Google Patents

Description

Process for the preparation of aliphatic α, ß-unsaturates Nitriles In US Pat. No. 3,655,722 there is a method of making and Isolation of certain 7-methyl-octadiene-2,6-nitriles by condensation of Cyanoacetic acid with 2-methylhepten-2-one -6 in the presence of an amine or an amine addition salt or an acid at a temperature between 40 and 180 ° C. You get a mixture of nitriles useful in perfume compositions. Under The compounds produced are neronitrile and geranonitrile.

These compositions for perfumes may be used alone or incorporated can be used in soaps, detergents, aerosols or cosmetics.

This known method gives the unsaturated nitriles in fairly low yields, resulting in a relatively high cost price for this gives nitriles. The direct yield of geranonitrile and neronitrile is about 22, while the actual yield, after recovery of the methylheptenone, that did not respond is around 40%.

In Angewandte Chemie 84, 767 (1972), Angewandte Chemie Internationale output 11, 722, (1972) and in DOS 2 135 666 is the reaction of acetonitrile with ketones, such as cyclohexanone for the production of cyclohexylideneacetonitrile in the presence of a Alkali alcoholate from a high boiling point alcohol, i.

with a boiling point above the highest boiling point of one of the Be components of the reaction mixture described. For example, n-octanol is used. It it is indicated that the reaction with an alkali metal ethylate depends on a degree of conversion from 5 to 10% comes to a standstill as this occurs during hydrolysis of the alcoholate formed ethanol is removed by distillation.

The basicity of the remaining alkali hydroxide would then be insufficient, to attach a proton to the acetonitrile.

The water is azeotroped by distillation according to the sequence removed from the reaction and a yield of 70% is obtained in the case of cyclohexylidene acetonitrile.

In accordance with the invention there has now been a process for making aliphatic a, B-unsaturated nitriles, starting from inexpensive reaction components, found. Excellent yields are obtained, which has the consequence that nitriles, how geranonitrile and neronitrile can be obtained with a low cost price.

According to the invention, an aliphatic ketone is reacted with acetonitrile in the presence of a basic compound selected from the group consisting of the hydroxides of the alkali metals, barium hydroxide, the alcoholates of the alkali metals of low molecular weight alcohols and the quaternary ammonium hydroxides. The acetonitrile pushes a radical CHON instead of oxygen of the carboxyl group of the ketone, with the formation of an unsaturated bond in a, B-position between the methylene carbon of the acetonitrile and the xeto carbon of the ketone. The reaction proceeds according to the following scheme: R ~ R RCR R - C - R (I) C = CHCN C 3 O + CH3CN basic | link RCR RCR RR In the above formulas, the symbols R, which can be identical or different, denote hydrogen atoms, alkyl radicals having 1 to 20 carbon atoms and alkenyl radicals having 2 to 20 carbon atoms.

Using an aliphatic unsaturated ketone gives one is an aliphatic α, ß-unsaturated nitrile, while if one is an aliphatic Monoethylene ketone is used, one is a diunsaturated aliphatic nitrile receives.

If geranonitrile and neronitrile are to be produced, the starting ketone is methylheptenone: Other ketones that can be used are: 3, 6-Dimethylhepten-5-one-2, 3,6-Dimethylheptenone-2, 7-methylocten-6-one-3, 7-methyloctenone-3, 6-methylhepten-5- one-2, 6-methylheptenone-2, 4,7-dimethylocten-6-one-3, 4,7-dimethyloctenone-3, 2, 7-dimethylocten-6-one-3 and 2,7-dimethyloctenone-3.

The following can be mentioned as further ketones: The reaction takes place with stoichiometric proportions of ketone and acetonitrile. It is also possible to use an excess of one and the other of the reactants, if so desired. If you use an excess of ketone or acetonitrile, this can be recovered at the end of the reaction and returned to the circuit.

Any strongly basic compound can be used. For example, the alkali metal hydroxides, such as sodium * r potassium hydroxides and the alkali metal alcoholates of low molecular weight aliphatic alcohols with 1 to 4 carbon atoms, such as potassium tert-butoxide, sodium propoxide, potassium isopropoxide, sodium ethylate, potassium methylate, sodium butoxide, potassium isobutoxide, potassium isobutoxide; one can also use barium hydroxide. One can also use quaternary ammonium hydroxyls, known as strong bases, which correspond to the following formula: in which the symbols R1, which can be identical or different, denote alkyl, cycloalkyl, aryl or haloaryl radicals having 1 to 30 carbon atoms, it being possible for these radicals to be substituted by hydroxyl, alkyl, hydrozyalkyl radicals or by halogen atoms.

The basic compound remains unchanged during the reaction and can therefore be used in a wide variety of dosages, preferably between 0.01 moles and 10 moles per mole of ketone.

In general, between 0.1 and 5 moles of basic compound are used Per mole of ketone. In principle it is not necessary to use more than 1 mol of basic compound To be used per mole of ketone.

It is advantageous if the basic compound is at least partially is in solution, in which case the rate of reaction greater is. So you can use an organic solvent for the reaction gel add basic compound (especially barium hydroxide), such as dimethyl sulfoxide or m-pyrrole. Such solvents increase the activity of the basic compound. However, it is not absolutely necessary to add an inert solvent because the acetonitrile can act not only as a reactant but also as a solvent can be used and for this purpose it can be used in excess. The presence of acetonitrile is also advantageous, since the acetonitrile can serve to hold back the water. The water that has accumulated in the course of the reaction becomes in the course of the hydrolysis in a basic medium of acetonitrile with the formation of Acetamide fixed.

Other water scavengers can also be used, such as molecular filters.

It can also be advantageous to add an inert solvent, which is optionally a solvent for the basic compound, but that is results in an azeotropic mixture with the water, in such a way that in the course of the Water formed in the reaction can be removed by azeotropic distillation. This For example, water can be collected under reflux in a water separator and is not returned to the reaction cycle. As a suitable azeotropic Solvents can be called toluene, benzene and the xylenes.

The reaction occurs already at ordinary or slightly below lying temperature. However, it is accelerated by increasing the temperature. The maximum reaction temperature is determined by the decomposition temperature of the α, ß-unsaturated Nitrile limited. In general, the reaction temperature should not exceed 2000C and can be lowered to 20 0C or below. The preferred temperature range lies between 50 and 1250C.

The reaction can be carried out under atmospheric pressure.

However, if you have a volatile solvent and a reaction temperature used near its boiling point under atmospheric pressure, it is advantageous to to work in a closed vessel like an autoclave to remove the solvent to keep liquid in the reaction mixture; or you can also work under reflux.

The reaction is complete in about 30 minutes, but in some Cases can also last up to 120 hours or more.

However, this is not a deficiency because the α, ß-unsaturated Nitrile is the end product and there is no further conversion of this product. You can increase the reaction time by increasing the reaction temperature, by improving the effectiveness of stirring and by using the reactants in concentrated Abbreviate the state.

After the reaction has ended, the reaction mixture is treated with an acid to neutralize the basic compound.

The reaction product is then dissolved in an organic solvent, such as benzene, which is immiscible with the aqueous phase, and separates on this Separate the aqueous phase from the organic phase containing the reaction product. In order to optimize the yield, the aqueous phase can be mixed with the solvent several times extract.

Another procedure can be used with the reaction mixture Wash water to remove most of the basic compound and the acetamide remove. The remaining organic phase is then washed with a dilute aqueous acid solution to make sure that all residues of the basic Connections are removed. The same result can be achieved by filtering the crude reaction mixture to remove most of the basic compound and the acetamide and reusing the acidic wash waters for removal any alkaline residues. One can use the acidic washing liquids unite and extract them with a low boiling point organic solvent, to optimize the extraction of the product.

The organic phases can be concentrated to drive off the solvent, preferably under reduced pressure and at low temperature and then the Distill residue under reduced pressure to get the starting materials, which are not have reacted to separate, i.e. the starting ketone and the acetonitrile. It remains the a, ß-unsaturated nitriles in the form of a cistrans mixture, if stereoisomers are possible, but their separation is generally not necessary.

The following examples are intended to explain the invention in more detail.

Example 1 The mixture is heated under reflux to 840 with mechanical stirring and the following mixture under a nitrogen atmosphere for 72 hours: sodium hydroxide (1 mole) .................. 40 g acetonitrile (10 mol) ............................ 410 g of 3,6-dimethylhepten-5-one-2 (containing about 15 ffi of 7-methylocten-6-one-3) 135 135 g The reaction mass is allowed to cool and 550 g of an aqueous, 10 percent acetic acid solution to neutralize the basic compound.

50 cc of benzene are added, the mixture is stirred and then decanted and separates the aqueous layer. The aqueous layer is treated twice with 50 cc benzene, then twice with 25 cc benzene and collect the benzene extracts. the Layers of benzene are collected, the benzene removed below 40 mm Hg, and the residue under a pressure of 2 to 5 mm Hg and at a temperature at the top of the column distilled between 50 and 130 ° C, being the temperature of the alley is between 58 and 15,800.

In this way one obtains 111.6 g of the starting ketone which does not react has and 20.4 g of a mixture of 3,4,7-trimethyloctadiene-2,6-nitrile and 3-ethyl-7-methyloctadiene-2,6-nitrile.

The direct yield of dienic nitrile is 13% and the actual Yield is 75%.

This nitrile mixture has an orange-like odor that reminiscent of that of citral, fresh, clean and intense. Its fleeting and lively character is very attractive and in the range of natural orange scents very popular these days. A hint of a distinctly bitter note intensifies his Attractiveness. An intense and persistent fragrance are important additional properties.

Besides its use in compositions with an orange scent, such as Orange, neroli, citron and cologne make this mix an excellent ingredient for lavender, fern or spruce needle smells, for moss, hay and wood smells. It is effective in floral perfumes, such as rose and lily of the valley perfume, when you use it used in small doses. You can find 25% and more of this in perfumes with a lemon scent note use according to the end use purpose. The mixture of nitriles is opposite very resistant to acidic and alkaline environments and, as a result, in products such as Detergents, soaps, depilatory agents, permanent waving agents and hair rinsing agents can be used.

Example 2 The mixture is heated under reflux with mechanical stirring and the following mixture under a nitrogen atmosphere for 15 hours: potassium hydroxide (1 mol) ........................ 56 g acetonitrile (10 mol) ............... ......... 410 g 3,6-dimethylhepten-5-one-2 (containing about 15% 7-methylocten-6-one-3) .................... 135 g. After cooling, the reaction mixture is poured into 900 cc one 10 percent aqueous acetic acid solution to neutralize the basicity.

50 cc of benzene are then added, the reaction mass is stirred and separated the benzene layer off. The aqueous layer is extracted with 50 cc of benzene and combined the benzene layers and chases the benzene below 40 mm Hg. The resulting oil will Washed three times with 25 cc of 10 percent hydrochloric acid and each extract is in turn extracted four times with 10 cc benzene. Combine the benzene extracts, drive away the benzene below 40 mm Hg and the remaining oil distilled below 1 to 5 mm Hg and at a temperature at the top of the column between 50 and 121 ° C, while the The temperature of the reaction mass is between 78 and 1520C. This gives 11.2 g of unchanged starting ketone and 113.6 g of a mixture of 3,4,7-trimethyloctadiene-2,6-nitrile and 3-ethyl-7-methyloctadiene-2,6-nitrile. The direct yield is 72.3% and the actual yield 78.9.

Examples 3 to 21 The mixture is heated under reflux to 840 ° C. under mechanical pressure Stir and under a nitrogen atmosphere for 4 1/2 hours the following mixture: Ealium hydroxide (0.2 mol) ................. 11.2 g acetonitrile (2 mol) ................. .............. 82 g methylheptenone ............................... 25.2 g After cooling, pour the reaction mass is stirred in 125 cc of aqueous acetic acid and the mixture is stirred Mixture with 25 cc of benzene and separates the benzene layer. Wash the benzene layer twice with 10 cc of 10 percent hydrochloric acid and the aqueous layer extracted three times with 15 cc benzene.

The benzene layers are collected and the benzene is chased away in a vacuum, then the remaining oil is distilled below 4.5-0.8 mm Hg at a temperature at the head of the column between 80 and 95 ° O while the temperature the reaction mass is between 94 and 1640C.

This gives 0.5 g of unreacted methylheptenone and 16.9 g of geranonitrile. The direct yield is 56.8% and the actual yield is 58.

Using this procedure, various ketones are converted according to the conditions given in the table below. Tabel MOLE PER MOL% BY GAS / LIQUID KETONE KEITSCHROMATOGRAPHY EXAMPLE ACT% NO. KETONE AND NITRILE ACETO CATALYST TEMP DURATION DIRECT INITIAL% NITRILE TOR ° C HOURS YIELD YIELD KETONE NITRILE 4 10 1 NaOH 81 80 13.0 74.6 84.7 15.3 5 3,6-dimethylhep- 10 4 NaOH 85 35 81.4 18.6 ten-5-on-2 # 6 3,4,7-trimethyloc-10 1 KOH 88 16 75.4 84.4 10.8 89.2 tadiene-2,6-nitrile 7 10 0.1 NaOCH3 84- 42.5 87.2 12.8 86 8 and 10 0.1 KOH 84-91 63.0 77.2 19.3 76.8 85 9 10 1 NaOCH3 82- 45.3 63.5 66.4 5.2 91.5 83 7-methyloctene-6- 10 on-3 10 1 NaOCH33 76-45.5 49.5 68.2 32.0 67.6 # 77 3-ethyl-7-methyl- 11 octadiene-2,6-ni- 10 5 KOH 87-2.5 63.0 76.2 18.6 79.7 tril 100 12 6-methylheptene-5- 10 1 KOH 30-35 46 52.1 45.2 on-2 # 60 6 37.7 61.6 46.1 52.9 3,7-dimethylocta- 13 diene-2,6-nitrile 10 0.1 KOH 83 25 56.5 63.6 13.6 80.9 Table (continued) MOLE PER MOL% BY GAS / LIQUID KETONE KEITSCHROMATOGRAPHY EXAMPLE ACT% NO. KETONE AND NITRILE ACETO CATALYST TEMP DURATION DIRECT INITIAL% NITRILE TOR ° C HOURS YIELD YIELD KETONE NITRILE 4,7-dimethyloctene 14 6-on-3 # 10 1 KOH 83-112 34.1 36.6 13.9 58.8 3-ethyl-4,7-dime-119 thyloctadiene-2,6- nitrile 15 2,7-dimethyloctene-10 1 KOH 84- 88 42.7 67.5 43.6 51.1 6-on-3 # 109 7-methyl-3-isopro- pylnonadiene-2,6- nitrile 16 3,6-dimethylheptene-1 0.1 KOH 128- 46 21.8 50.7 69.4 30.5 5-on-2 # 139 17 3,4,7-trimethyloc-10 0.1 NaOH 1 84-0.6 47 54.4 19.6 80.4 tadiene-2,6-nitrile 105 and 7-methyloctene-6- 18 on-3 # 50 1 KOH 84 24 70.3 96.4 22.6 77.4 3-ethyl-7-methyl- octadiene-2,6-nitrile 19 6-methylheptene-5- 10 1 NaOH 1 27 30 22 51.8 48.2 on-2 # 50-65 1 28.4 31 20.2 79.8 3,7-dimethylocta- diene-2,6 nitrile Table (continued) MOLE PER MOL% BY GAS / LIQUID KETONE KEITSCHROMATOGRAPHY EXAMPLE ACT% N °. KETONE AND NITRILE ACETO- KATALYSA- TEMP. DURATION DIRECT OUTPUT% NITRILE TOR ° C HOURS YIELD YIELD KETONE NITRILE 3,6-dimethylhep- 20 ten-5-one-2 10 1 NaOH 2 50-55 16 51.7 64.5 27.5 72.5 # 85-88 8 3,4,7-trimethyloc- tadiene-2,6-nitrile and choline-4 73 20.4 77.6 75.4 29.2 21 7-methyloctene-6- 10 base 45% 76 on-3 in metha- # nol 3-ethyl-7-methyl- octadiene-2,6-ni- tril 19-1 dimethyl sulfoxide, 780 g per mole of ketone 3 methyl alcohol, 324 g per mole of ketone 2 m-pyrrole, 1000 g per mole of ketone 4 choline base [(CH3) 3 (CH3CH2OH) N] OH Examples 22 to 28 In a pressure-resistant reaction vessel Glass with a magnetic stirrer covered with Teflon is poured: 6-methylhepten-5-one-2 (0.1 mol) ............... ....... 12.6 g acetonitrile (1 mole) ................................. 41 g of potassium hydroxide (0.01 mol) ......................... 0.55 g. The vessel is closed, heated with stirring for 2 hours between 105 and 11400 and then cools down.

The reaction mixture is then poured into 125 cc of aqueous acetic acid, then 25 cc of benzene are added. The benzene layer is separated from the aqueous layer and washes them with 10 cc of 10 percent hydrochloric acid.

The aqueous layer is extracted three times with 15 cc of benzene.

You collect the benzene layers and drive the Benm vacuum away. One distills the remaining oil between 4.5 and 0.8 mm Hg at a temperature at the top of the Column between 80 and 950C, while the temperature of the mass between 94 and 164 ° C amounts to. In this way, 1.4 g of unreacted methylheptenone are obtained and one receives 6.8 g of geranonitrile.

The above procedure is followed and various ketones are used under the conditions given in the table below: Table MOLE PER MOL% BY GAS / LIQUID KETONE KEITSCHROMATOGRAPHY EXAMPLE ACT% N °. KETONE AND NITRILE ACETO- KATALYSA- TEMP. DURATION DIRECT OUTPUT% NITRILE TOR ° C HOURS YIELD YIELD KETONE NITRILE 22 3,6-dimethylheptene-10 0.1 KOH 106- 7.75 61.2 69.4 13.0 79.1 5-on-2 114 # 23 3,4,7-Trimethyloc-10 0.1 NaOH5 108- 8.75 89.9 10.1 tadiene-2,6-nitrile 114 and 24 7-methyloctene-6- 10 0.1 KOtBu 105 11.5 54.9 76.8 30.7 69.3 on-3 # 25 3-ethyl-7-methyl-10 0.1 KOH 148-4.5 49.8 63.6 26.4 73.6 octadiene-2,6-nitrile 150 26 10 1.0 Ba (OH) 24 105 53.71 15.2 44.0 78.2 20 124 4 dimethyl sulfoxide, 780 g / mol ketone 5 36 g methanol / mol ketone The α, β-unsaturated nitriles obtained according to the invention are useful constituents for perfume bases. They can be used alone in such basic bodies or mixed with other organic compounds, such as alcohols, aldehydes, ketones, esters or hydrocarbons, in such a way that the preparations lead to overall pleasant fragrances. Such base bodies for perfumes or fragrances can be used alone or as an additive to soaps, detergents, aerosols, cosmetics, depilatory agents, permanent waving agents or hair rinsing agents.

In the basic bodies for perfumes or fragrances, every connection controls their characteristic scent note, but the overall effect is the sum of all Components. The α, β-unsaturated nitriles obtained according to the invention can be added be used, the fragrance properties of a product for perfumes or

Modify fragrances by the odor contribution of the other ingredients the composition is increased or decreased.

The following examples explain the use of the invention available a, ß-unsaturated nitriles.

Example 27 Preparation of Soaps 100 g of soap flakes are mixed with 1 g of each of the compositions given below until a practical homogeneous mass. The two soaps have a lemon odor and the composition, which contains the mixture obtained according to Example 1, gives the finer flavor.

These compositions have the following ingredients: Parts by weight Geranium bourbon ................................................. .... 175 Citronellol .................................................. ....... 150 Geraniol ......................................... ................... 100 phenylethyl alcohol ................................................ .. 90 amylcinnamon.aldehyde 200 Cyclamal (cyclamenaldehyde) ...................... 20 4- (4-Methyl-4-hydroxyamyl) -cyclohexene-9-carboxaldehyde .................................................. ..... 100 tetrahydrolinalol ........................................... ........ 37.5 tetrahydromyrcenol .............................................. .... 37.5 Linalool ................................................. ........... 75 Citronellyl Acetate .................................................. 125 Phenylethyl acetate 5 Phenyl acetaldehyde dimethyl acetal .................................... 10 cinnamon alcohol ............ ............................................. 35 terpineol ................................................ ........... 100 linalyl acetate .................................................. ..... 25 musk ketone ........................................... ............. 10 indole ................................................ ............... 10 mixture from Example 1 or 2 ................. 10 Example 28 Manufacture of a cosmetic Powders A cosmetic powder is produced by mixing 100 g of talc powder with 0.25 g of the mixture obtained in Example 1.

The powder has a citron-like odor.

Example 29 Preparation of a detergent 100 g of a detergent are mixed Detergent product with 0.15 g of a fragrance composition, which according to Example 1 mixture obtained until you get a practically homogeneous composition with lemon-like odor. The fragrance composition used includes the following Components: Parts by weight of decylaldehyde, 10 percent solution in ethyl phthalate * 4 terpinylacetate ............................................. ......... 100 terpineol ................................................ ........... 40 linalyl acetate .................................................. ..... 100 orange oil ........................................... ................ 350 geranyl acetate ................................................ ....... 100 geraniol .................................................. .......... 35 Coumarin ...................................... ....................... 2 Mixture of Example 1 ........................... 70 Example 30 Liquid detergent.

One makes liquid concentrated detergents with a lemon-like Odor, which contain 0.1, 0.2 or 0.5% of the mixture of Example 1.

The amount of the mixture or the compound according to the invention which is necessary in the fragrance compositions depends on various factors including of the other components, their amount and the desired effect. It was determined, that fragrance compositions, which only 0.02% or even less of the invention Containing compounds, advantageously used for various fragrance compositions can be. It is also possible to use up to 5 percent by weight or more.

In general, about 1 to 3 5 of the fragrance mixtures are used in the soaps. So you can get as little as 0.0002 percent by weight of a product according to Use the invention to make soaps, cosmetics or other products a lemon-like To give smell.

Claims (1)

Claims 9 Process for the preparation of aliphatic α, ß-unsaturated nitriles of the general formula in which the symbols R, which can be identical or different, denote hydrogen atoms, alkyl radicals with 1 to 20 carbon atoms or alkenyl radicals with 2 to 20 carbon atoms, characterized in that acetonitrile is mixed with a ketone of the general formula (R) 3C - CO - C ( R) 3 reacts at a temperature between 20 and 2000C in the presence of a strongly basic agent. 2-. Process according to Claim 1, characterized in that methylheptenone used. 3. Use of the nitriles prepared according to claim 1 for the production of perfumes and other fragrance compositions.