PL155265B1 - Method of obtaining a mixture of methyl-1-methyl-2-phenyl-methyl and methyl-2-methyl-2-phenyl-methyl carbinols for perfume making purposes - Google Patents

Description

RZECZPOSPOLITA PATENT DESCRIPTION 155 265 POLAND

Additional patent to patent no - Pending: 87 03 11 (P. 264559)

Precedence - Int. Cl. ⁵ C07C 33/20 C11B 9/00

OFFICE

PATENT

RP ^Notification announced: 88 ^{10 13}

Patent description published: 1992 03 31

G 6 Łfl A

Creators of the invention: Iwona Szydłowska, Grzegorz Wiśniewski, Andrzej Malasiewicz, Maria Bełdowicz, Władysław Brud, Mirosław Pilecki,

Urszula Chmielowiec

The holder of the patent: Industrial Chemistry Research Institute,

Warsaw Poland)

Method of obtaining a mixture of methyl-1-methyl-2-phenylethyl carbinol isomers and methyl-2-methyl-2-phenylethyl carbinol for perfumery purposes

The invention relates to a continuous process for the preparation of a mixture of methyl-1-methyl-2-phenylethyl and methyl-2-methyl-2-phenylethyl carbinol isomers for perfumery purposes by hydrogenating methyl benzylidene acetone in the presence of a catalyst.

So far, the hydrogenation processes of methylbenzylidene acetone have been carried out under batch conditions, using Raney nickel or using sodium in ethanol. Sodium reduction methods are non-technological and have no industrial significance today.

In the presence of Raney nickel, methyl-2-methyl-2-phenylethyl carbinol was obtained from methyl benzylidene acetone for perfumery with the scent of patchouli leaves with a green hint (as assessed by the FSZ Fragrance Laboratory "Pollena-Aroma). The conversion is 90% and the selectivity is 85%. The disadvantage of the processes in which Raney nickel is used is the necessity of such technological operations as the preparation of the catalyst and its filtration after the finished process, and the associated generation of large amounts of sewage and waste.

It turned out that by carrying out the hydrogenation process of methylbenzylidene acetone on a copper catalyst bed, a mixture of methyl-1-methyl-2-phenylethyl and methyl-2-methyl-2-phenylethyl carbinols is continuously obtained with a very high yield of over 90%. It turned out that by carrying out the hydrogenation process on the bed of the mixing catalyst in a basic medium, preferably in an organic solvent, a mixture of isomers of substitution of the methyl group in the a and β position in relation to the aromatic ring was obtained, which unexpectedly resulted in the obtained mixture being characterized by very interesting new aroma characteristics. .

The obtained mixture of methyl-1-methyl-2-phenylethyl and methyl-2-methyl-2-phenylethyl carbinols is characterized by a rose-lily of the valley smell and received a rating of 6 on an 8-point scale (according to the FSZ Smell-Applied Laboratory "Pollena-Aroma" ).

155 265

The hydrogenation process is carried out under strictly defined conditions of temperature, pressure and substrate loading of the catalyst, so that the content of the partial hydrogenation product of only the double bond in the unsaturated ketone does not exceed 2%.

The method of obtaining a mixture of methyl-1-methyl-2-phenylethyl and methyl-2-methyl-2-phenylethyl carbinols according to the invention consists in passing methylbenzylidene acetone co-current, preferably in an organic solvent with the addition of 0.25-0.5% KOH and hydrogen gas through the catalyst bed copper, placed in an industrial reactor at a temperature of 423-443 K, under a pressure of up to 2.0 MPa and a substrate load of 0.08-0.24 dm ³ / dm ³ cat / hour on the catalyst. The perfume-pure product is obtained by vacuum rectification.

The process carried out in this way is characterized by a very high degree of conversion equal to 100%, an exceptionally high selectivity of over 90%. Other advantages of the continuous hydrogenation process in the presence of a copper casalizer are the lack of wastewater and waste as well as the high apparatus simplicity of this technology.

The subject of the invention is shown in the example.

Example in a tube reactor^ym cleaned up^0,7 dm^{3 k}ataHzator copper^gabout.^K.atah the embolus was activated at 468 K under a stream of hydrogen. After the reduction was completed, the temperature was lowered to 423 K and hydrogen was passed through co-current at a pressure of 1.5 MPa and methyl benzylidene acetone dissolved in anhydrous ethanol with 0.5% KOH added at the required load. After passing through the water condenser, the product mixture was collected in a separator.

The results of the chromatographic analysis of the crude product are shown in the table.

As a result of vacuum rectification of the raw product with the composition presented in the table, a product with a purity of 98.1% and a very good fragrance quality is obtained. The perfume fraction of perfume-pure synthetic material was collected at 384 K under a vacuum of 0.3 kPa.

The results obtained in the example show that the method of obtaining a fragrance from methylbenzylideneacetone provides 100% conversion of the raw material, and the main product (over 90%) is a mixture of methyl-1-methyl-2-phenylethyl and methyl-2-methyl-2-phenylethyl carbinol, rose-lily of the valley.

Table

Hydrogenation of methylbenzylidene acetone under variable catalyst load. Temperature 423 K, pressure 1.5 MPa

The composition of the reaction mixture in% by weight

Catalyst loading with raw material dm ³ / dm ³ cat / hour Propanol Benzene 1-phenyl-1,3-butadiene 3 methyl 1-phenylbutane 4 methyl-benzy- loacetone mixture isomers carbinols others products Degree transformations % '. Selek- agility % 0.11 trace trace trace trace 1.68 91.74 6.62 100 91.7 0.14 0.59 0.27 0.42 0.25 0.75 96.55 1.12 100 96.6 0.20 0.32 0.35 - - 1.35 95.98 2.0 100 96.0

Claims (1)

Patent claim A process for the preparation of a mixture of methyl-1-methyl-2-phenylethyl carbinol isomers and methyl-2-methyl-2-phenylethyl carbinol by hydrogenation of methylbenzylideneacetone in the presence of a catalyst, characterized in that methylbenzylidene acetone is hydrogenated, preferably in an organic solvent in the presence of 0.25- 0.5% KOH with hydrogen gas, co-current passed on the copper catalyst, maintaining the hydrogen pressure to 2.0 MPa with the substrate loading of the catalyst 0.08-0.24 dm ³ / dm ³ cat / hour. at a temperature of 423-443 K. Department of Publishing of the UP RP. Circulation 100 copies Price: PLN 3,000