DE1249249B - Process for the preparation of α, β-unsaturated aldehydes or ketones - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C07c

German class: 12 ο-7/03 Ί Z / Hf '> ¹ 9 /

Number: 1249 249

File number: S 81050IV b / 12 ο

Filing date: August 22, 1962

Opened on: September 7, 1967

The invention relates to a method of manufacture of «, ^ - unsaturated aldehydes or ketones Oxidation of Λ. / 5-unsaturated alcohols. The method is characterized in that one unsaturated alcohol of the general formula

; C = CH - CH ₂ OH

in which R a) represents hydrogen, methyl or phenyl, if R 'represents hydrogen, or b) represents the 4-methylpentene- (3) -yl- (l) radical or the 4-methyl-6- [2nd ', 6', 6'-trimethylcyclohexen- (l) -yl- (l ')] -haxatrien- (l, 3, 5) -yl- (l) radical, if R' is methyl, with 1 to Reacts 2 molar equivalents of nickel peroxide in an inert organic solvent at a temperature of 0 to 90 ⁰ C.

The nickel peroxide can be prepared by using a nickel salt, e.g. B. nickel chloride, nickel »o sulfate, nickel carbonate, nickel nitrate, with a strong oxidizing agent such as alkali hypohalite, e.g. B. sodium hypochlorite, Potassium hypochlorite, sodium hypbromite, or alkali persulfate, e.g. B. Sodium Persulfate, Potassium persulfate, treated in an aqueous alkaline medium. A preferred manufacturing method of this nickel peroxide is the following:

To a solution of 130 mg Nickelsulf at hexahydrate in 300 ml of water a solution of 42 g of sodium hydroxide in 300 ml of 6 ° / _o sodium hypochlorite is added dropwise introduced under stirring, and the resulting mixture is stirred for about 30 minutes at a temperature between 10 and 25 ⁰ C stirred. The black precipitate is collected by filtration, washed with water to remove the active chlorine and, after the cake is ground to a powder, dried over anhydrous calcium chloride under reduced pressure.

The nickel peroxide obtained in this way is a black, fine powder which contains a certain amount of water. The analysis revealed a possible molar formula, Ni ₈ O ₃ -SHjO or Ni (OH) ₃ , but the structure of this body is unknown. This nickel peroxide has usually about 0.3 to about 0.4 x 10 ~ ^a gram atoms of free oxygen per gram as measured by titration of precipitated in the reaction between the nickel peroxide and potassium iodide in acetic acid iodine with sodium thiosulfate. A considerable amount of this free oxygen is gradually lost on heating, but remains for a longer time when stored at room temperature under protection from atmospheric processes for the production of \, / J-unsaturates
Aldehydes or ketones

Applicant:

Shionogi & Co., Ltd., Osaka (Japan)

Representative:

Dr. phil. Dr. rer. pole. K. Köhler, patent attorney,

Munich 2, Amalienstr. 15th

Named as inventor:

Kunio Nakagawa, Nishinomiya-shi;

Takamori Konaka, Amagasaki-shi (Japan)

Claimed priority:

Japan August 25, 1961 (30 817)

Moisture. Since the nickel peroxide obtained in this way has a particularly large surface area in proportion to its weight, the free oxygen can be used effectively in the oxidation reaction will. In view of the favorable properties of this reagent, oxidation be terminated advantageously in a short period of time.

The optimum reaction conditions, such as the reaction medium, reaction temperature, reaction time and the amount of oxidizing agent, are essentially dependent on the type of unsaturated alcohol used as the starting material. It is therefore advisable to set the conditions for each case. As a reaction medium, for. B. hydrocarbons, ethers, halogenated hydrocarbons, acid amides and thioethers are used. The reaction is conducted at 0 to 90 ⁰ C, usually at about 30 to 70 ⁰ C is performed. A particular advantage of the process according to the invention is that the reaction can also be ^{carried out in a satisfactory manner at temperatures below 30 ° C.} This is particularly advantageous if the process according to the invention is applied to the oxidation of compounds which are unstable in terms of heat. The reaction time can be from 30 minutes to 12 hours, usually 3 to 6 hours. The amount of nickel peroxide used is 1 to 2, usually 1 to 1.2 molar equivalents.

The recovery of the reaction product from the reaction mixture can take place in such a way that first the nickel peroxide filtered and the filtrate worked up in the usual way.

709 640 / 56t!

The nickel peroxide used in the oxidation reaction can easily be made by treating nickel peroxide with a strong oxidizer, such as Alkali hypohalites or alkali persulfates, are renewed in an aqueous alkaline medium. A Example of this regeneration is the following:

The filtered nickel peroxide is washed with water with about ten times the amount of the nickel peroxide of 6% sodium hypochlorite, in one aqueous alkaline medium stirred for 20 minutes, filtered, washed with water and dried.

The following examples illustrate the process of the invention.

example 1

To a solution of 3.028 g of cinnamyl alcohol in 30 ml of benzene is added nickel peroxide in 1.2facher amount of theoretical and the resulting mixture stirred for 1 hour at 5O ⁰ C and then filtered. After removing the solvent, the crude cinnamaldehyde is obtained, which has been characterized as 2,4-dinitrophenylhydrazone (4.034 g), E. 254 "C.

Example 2

To a solution of 3 g 2-butene-l-ol in 30 ml ether 2 times the theoretical amount NicVeiperoxyd is added, the mixture was stirred for 6 hours at 2O ⁰ C and then filtered. After removal of the solvent from the filtrate gives the crude crotonaldehyde, welcherals2,4-dinitrophenylhydrazone (2.15 g), mp 187 ⁰ C, was characterized.

Example 3

A solution of 3 g of allyl alcohol in 30 ml of ether is added nickel peroxide with the l, 5 times the theoretical amount, the mixture was stirred for 6 hours at 20 ⁰ C and then filtered. After removal of the solvent, to 79 ° / _o yield acrolein.

Example 4

To a solution of 5 g of geraniol in 90 ml of benzene 2 times the theoretical amount of nickel peroxide is added, the mixture was stirred for 6 hours at 50 ⁰ C and then filtered. After removal of the solvent from the filtrate, 4.05 g of citral receives ° / ₀ strength purity in a 91.6.

Example 5

A solution of 100 mg of vitamin A in 15 ml of petroleum ether are added to 250 mg of nickel peroxide, the mixture was stirred for 1 hour at 15 to 20 ⁰ C and then filtered. After removal of the solvent from the filtrate yields the oily retinene in a 79.1. ° / oig ^eri yield.

Claims (1)

Claim: »O Process for the production of χ, / 2-unsaturated Aldehydes or ketones by oxidation of Λ, / S-unsaturated alcohols, characterized in that one unsaturated Alcohol of the general formula R. R ' .: C = CH - CH ₂ OH in which R a) represents hydrogen, methyl or phenyl, if R 'represents hydrogen, or b) represents the 4-methyl-pentene- (3) -yl- (l) radical or the 4-methyl-6- [2 ', 6', 6'-trimethyIcyclohexen- (l ') - yl- (l')] · hydroxatriene- (l, 3,5) -yl- (l) radical, if R 'is methyl, with 1 to 2 molar equivalents of nickel peroxide in an inert organic solvent at a temperature of 0 to 90 ⁰ C. Considered publications:
German patent specification No. 127 388. 709 640/561 8.67 © Bundesdruckerei Berlin