DE1043319B - Process for the production of new unsaturated ketones with special fragrance properties - Google Patents

Description

Process for the production of new unsaturated ketones with special odorous substance properties The invention relates to a process for the production of new unsaturated ketones with special odorous substance properties, which is characterized in that a tertiary alcohol of the general formula is used in which R1 is an alkyl radical with 2 to 4 carbon atoms and R2 is either the methyl radical or, together with the radical Rj, the pentamethylene radical, treated with an inorganic halogenating agent, the substituted primary allyl halide formed is condensed with an alkali acetoacetic ester and the substituted acetoacetic ester formed is saponified and decarboxylated, Examples of starting alcohols are as follows: 3,7-dimethyl-nonadiene- (1,6) -ol - (3) -3,7,9-trimethyl-decadiene- (1,6) -ol- (3) and 3-methyl -6-cyclohexylidene-hexen- (1) -ol- (3).

Preferred halogenating agents in the first reaction stage are concentrated, aqueous hydrohalic acids, e.g. B. the commercially available concentrated hydrochloric acid or hydrobromic acid, or phosphorus halides, such as Phosphorus trichloride is used.

During halogenation, an allyl rearrangement takes place with migration the double bond in the 2,3-position and linkage of the halogen with the istender Carbon atom.

In the next reaction stage, the substituted, primary allyl halide reacted with an acetoacetic ester. This happens in at known way z. B. by adding the halide in an inert solvent with the alkali salt of an acetoacetic ester, e.g. B. the sodium salt of ethyl acetoacetate, or by adding an alkali metal alcoholate to the mixture of the halide and the acetoacetic ester.

In the last stage of the reaction, the obtained are substituted Acetoacetic ester saponified and decarboxylated in a manner known per se. this happens expediently by treatment with an alkali hydroxide and subsequent acidification.

New ketones with fragrance character are formed, which have the following general formula: In this formula, R1 and R2 have the same meanings as above.

These new ketones have previously unknown, new odor nuances and can be used for the production of fragrance mixtures and perfumes.

Compared to related, previously known compounds such. B. geranylacetone, the substances prepared according to the invention are surprisingly different like odor qualities particularly suitable for perfumery purposes. You wise pleasant fruity Odor notes similar to those found only in esters are. However, esters are unstable in an alkaline medium. In contrast to such Esters, the ketones according to the invention are stable in a basic medium, so that they z. B. can be used in the perfuming of soap products without the The fragrance of such products is altered over time. Also is the adhesive strength of the new substances that can be produced according to the invention are significantly larger than that of fruity smelling esters.

Example 1 417.4 g of 3,7-dimethyl-nonadien- (1,6) -ol- (3) are mixed with Chilled to - 100C with the help of a bath made of solid carbon dioxide and acetone. Then, while stirring, 2080 cm3 of 370 / above aqueous hydrochloric acid is added to such an extent that that the temperature in the reaction vessel remains below 0 ° C. The encore lasts 30 Minutes after which the mixture is stirred for an additional 30 minutes.

The oil is removed with the aid of a separatory funnel and three times with Washed 500 cm3 of water each, after drying over calcium chloride, 485 is obtained g 1-chloro-3,7-dimethyl-nonadiene- (2.6) ft8S = 1.4750.

A 5 liter capacity with a stirrer, thermometer, condenser and dropping funnel The three-necked flask is filled with 2 l of benzene and 440 g of ethyl acetoacetate loaded. 175 g of sodium methylate are then added to this mixture in portions. When the latter is added, the temperature rises to 60 ° C. After stirring 485 g of 1-chloro-3,7-dimethylnonadiene are added dropwise over 30 minutes over the course of 30 minutes. (2,6) added. Di - the temperature of the realdione mixture is increased to 65 to 700 ° C and the mixture was stirred at this temperature for 10 hours.

Water is then added. The aqueous phase is removed and the benzene layer was washed twice with 200 cm3 of water each time. - The benzene will then removed in vacuo, with 3-carbethoxy-6,10-dimethyldodecadien- (5,9) -one- (2) remains, which is used for the next reaction stage without further purification will.

The total amount of 3-carbethoxy-6,1 0-dimethyl-dodecadiene (5 , 9) -on- (2) is mixed with 1.8 l of ethyl alcohol and with a solution of 280 g of potassium hydroxide mixed in 350 cm3 of water. This mixture is stirred for 4 hours 50 to 60 "C. The resulting solution of the potassium salt of 6,10-dimethyl-dodecadien- (5,9) -one- (2) -3-carboxylic acid is then obtained by the dropwise addition of 420 cm3 of 37% aqueous hydrochloric acid acidified, which takes 1 hour. The reaction mixture is left for 5112 hours Stirred at 60 to 70 ° C. and then mixed with 41 ° of water. The organic layer is separated off and the aqueous layer extracted three times with a total of 11 petroleum ether. The combined extracts to which the organic layer is added; earth over Calcium chloride dried, whereupon the solvent was removed and the residue passed through a Vigreux column is distilled.

In this way, 6,10-dimethyl-dodecadien- (5,9) -one- (2), which boils at 83 to 85 ° C / 0.1 mm; ort25 = 1.467. This connection developed a fine scent reminiscent of rose and lavender.

Example 2 142 g of 3,7,9-trimethyl-decadiene- (1,6) -ol- (3) become concentrated for 1 hour with 450 cm3, aqueous hydrochloric acid (37 percent by weight HCl) stirred at 25 "C.

The oily layer is separated, washed twice with water and dried over calcium sulfate. The dried liquid consists of 1-chloro-3,7,9-trimethyl-decadiene- (2,6); n25 = 1.472.

A 2 l flask is filled with 1000 cm3 of benzene and 104 g of ethyl acetoacetate and charged with 40 g of sodium methylate. After stirring the mixture for 30 Minutes are left within 30 minutes 145.5 g of 1-chloro-3,7,9-trimethyl-decadiene- (2,6) add dropwise using a dropping funnel. The reaction mixture is left for 4 hours stirred at 60 to 70 "C. After cooling to room temperature, the mixture is mixed with Washed 1000 cm3 of water and the benzene was then removed by distillation in vacuo. The one remaining in the flask The residue consists mainly of 3-carbethoxy-6,10,12-trimethyl-tridecadiene- (5,9) -on- (2).

The total amount of 3-carbethoxy-6,10,12-trimethyl-tridecadiene produced in this way Flask containing (5,9) - on - (2) is mixed with 500 cm3 of ethyl alcohol, 70 g of potassium hydroxide and 50 cm3 of water are added and the saponification is carried out by stirring the mixture during 4 hours at 40 to 50 ° C. The decarboxylation of the potassium salt formed of 3-carboxy-6,10,12-trimethyl-tridecadien- (5,9) -one- (2) is carried out by adding concentrated aqueous hydrochloric acid while stirring the mixture until it is strongly acidic reacted. The mixture is then stirred at 40 to 50 ° C. for a further 2 hours Cooling, the solution is diluted with 50 acm3 of water, the oily layer is separated and the aqueous part extracted with 500 cm3 of petroleum ether. The oily layer, which is combined with the oil obtained by extracting with petroleum ether washed with water and the solvent removed, whereupon the product in vacuo is fractionated. The 6,10,12-trimethyl-tridecadien- (5,9) -one- (2) distills at 107 to 109 "C / 0.7 mm; n2s - 1 4652 This material has a pleasant fruit-like appearance Smell and can be used to make floral-scented perfume compositions to give a fruity note. The compound thus obtained can also be used as a Component for synthetic fruit flavors, such as. B. those of pineapples, pears and Apples, can be used. Compared with those previously in similar perfumes and flavoring Esters used in compositions - the aforementioned ketone has an excellent, persistence not achieved.

Example 3 56 g of 6-cyclohexylidene-3-methyl-hexen- (1) -ol- (3) become at 25 "C for 1 hour with 150 cm3 of concentrated aqueous hydrochloric acid (37 percent by weight H Cl) stirred.

The oily layer is separated, washed twice with water and dried over calcium sulfate. The dried liquid consists of 3-methyl-6-cyclohexylidene-hexen- (2) -yl- (l) -chloride; n205 = 1.487.

500 cm3 of benzene and 52 g of ethyl acetoacetate are placed in a 2 l flask and registered 16.2 g of sodium methoxide. The mixture is stirred for 30 minutes and then drop by drop from a dropping funnel within 30 minutes with 55 g of 3-methyl-6-cyclohexylidene-hexen- (2) -yl- (l) chloride are added. The reaction mixture is stirred for 4 hours at a temperature of 60 to 70 "C. After cooling the mixture is washed at room temperature with 500 cm3 of water and the benzene removed in vacuo. The remaining, straw-colored oil consists mainly of from 3 - carbethoxy - 6 - methyl- 9 - cyclohexylidene - nonen- (5) -one- (2).

200 cm3 of ethyl alcohol, 35 g of potassium hydroxide and 50 cm3 of water are used in which the total amount of 3-carbethoxy-6-methyl-9-cyclohexylidene-nonen- (5) -one- (2) containing piston introduced. The saponification is carried out by stirring the mixture for 4 hours at 40 to 500 ° C. The decarboxylation of the potassium salt formed des 3-carboxy-6-methyl-9-cyclohexylidennonen- (5) -one- (2) is then added by adding of concentrated aqueous hydrochloric acid while stirring the reaction mixture until the same is strongly acidic. Then the mixture is stirred for a further 2 hours at 40 to 500 C, the solution cooled and diluted with 200 cm3 of water and the resulting oily layer severed. The aqueous part is extracted with 200 cm3 of petroleum ether. The oily one Layer and the oil obtained by extraction with petroleum ether are combined and washed neutral with water. Then the solvent is removed and the obtained product subjected to fractional distillation in vacuo. Included 6-methyl-9-cyclohexylidene-nonen- (5) -one- (2) is obtained, which at 114 "C / 0.4 mm distilled; n205 = 1.4886.

Claims (2)

PATENT CLAIMS: 1. Process for the production of new unsaturated ketones of the general formula which have special odorant properties in which R1 is an alkyl radical having 2 to 4 carbon atoms and R2 is either the methyl radical or, together with the radical R1, the pentamethylene radical, characterized in that a tertiary alcohol of the general formula in which R1 and R2 have the above meaning, treated with an inorganic halogenating agent which condenses the substituted primary allyl halide formed by allyl rearrangement in a manner known per se with an alkali acetoacetic ester and saponifies and decarboxylates the substituted acetoacetic ester formed in the customary manner. 2. The method according to claim 1, characterized in that as Halogenating agent concentrated aqueous hydrobromic acid or hydrochloric acid is used. References considered: U.S. Patent No. 2,638 484.