HU192527B - Process for oxidizing organic compounds containing double bond with singlet oxigen - Google Patents

Abstract

The present invention relates to a process for the oxidation of double bonded organic compounds by double bond. According to the invention, the double bonded organic compound is reacted in a homogeneous phase with the reaction of in-situ singlet oxygen produced by the reaction of organic peroxide or hydroperoxide and organic hypochlorite. -1-

Description

The present invention relates to a process for the oxidation of double-bonded organic compounds with singlet oxygen.

Singlet oxygen is a form of molecular oxygen that has an additional energy of 92 to 155kJ / mol relative to the ground state. The excess energy is caused by the modification of the electronic structure. Singlet oxygen has only recently been studied. A summary of the results so far can be found, for example, in Singlet Molecular Oxygen by A. Paul Schaap (Dowden, Hutchington and Ross, Stroudsburg, Pennsylvania, USA, 1976.) Singlet oxygen is an excellent oxidant, a special oxidant for double bond organic compounds, however, it has a very short lifetime and is rarely used in industrial oxidation processes.

Singlet oxygen in the reaction medium itself can be obtained by reacting hydrogen peroxide with sodium or potassium hypochlorite or hydrogen peroxide with bromine, by decomposing ozonides, especially triphenylphosphite ozonide, at about -30 ° C, and by directed decomposition of peracids and thermal decomposition.

The use of the resulting singlet in the oxidation of oxygen to organic compounds is hampered by many obstacles. Specifically, the disadvantages of the first two methods are that the reagent is difficult or non-soluble in commonly used organic solvents, i.e. in the medium containing the substrate to be oxidized. Thus, it is necessary to carry out the process in a heterogeneous phase in which the singlet oxygen is wholly or partially formed in the inorganic phase and then acts in the organic phase. While moving from one phase to another, some are deactivated. While triphenylphosphite-ozonide is soluble in several organic solvents, some of it is oxidized by itself, it can also oxidize the substrate without decomposing the singlet to oxygen. Thus, many undesirable oxidation by-products are formed, and the product requires a high degree of purification. Ozonides should be prepared and stored at low temperatures, such as -70 ° C. Another disadvantage is that they are explosive. The directed decomposition of the peracids is slow and pH sensitive. The peracids can directly oxidize the substrate and the solvent, and their use results in undesirable by-products. The disadvantage of endoperoxides is that these compounds themselves can only be produced by the oxidation of singlet oxygen and are difficult to isolate. Not all endoperoxides are capable of producing singlet oxygen. Endoperoxides form so-called mass transition complexes with many solvents; the singlet oxygen is generated inside the "cage" and by the time it gets out of it, it will in most cases lose its excitation energy. The use of singlet oxygen for the oxidation of organic compounds thus requires a number of difficulties.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process which is free of the above drawbacks and which allows the oxidation of double-bonded organic compounds in a homogeneous organic medium with singlet oxygen.

In our studies, it has been found that oxidation can be carried out in excellent yields using organic peroxide or hydroperoxide and organic hypochlorite as the reactant and the reaction is carried out in an organic solvent.

SUMMARY OF THE INVENTION The present invention relates to a process for the double bond oxidation of organic compounds containing double bonds with singlet oxygen. According to the present invention, the organic compound containing the double bond is reacted in a homogeneous phase with a singlet oxygen produced in situ by reaction of organic peroxide or hydroperoxide with organic hypochlorite.

The process of the invention depends on the structure of the double-bonded compounds!

suitable for three types of oxidation.

1. Conjugated double bond compounds can be made into endoperoxides, for example as shown in Scheme A or B.

2. Compounds containing isolated double bonds. They can be converted to a hydroperoxide during the en-reaction and then reduced to a hydroxyl group. This reaction type is illustrated in Reaction Scheme C.

3. The so-called. Reactive double bond compounds which do not contain hydrogen at the mobile position may be cleaved to carbonyl containing compounds as shown in Scheme D. Any aliphatic or aromatic moiety as substituent in the formulas herein may be substituted, and the double bond to be oxidized may be part of a three or four membered ring.

It has been found that any organic peroxide or hydroperoxide is capable of carrying out the oxidation, however, it has been found particularly advantageous for the organic substrate oxidation to be organic peroxides and hydroperoxides having one or more oxygen, sulfur, nitrogen and / or halogen substituents or there is a functional group. Namely, such compounds can be complexed or hydrogen bonded to the compounds to be oxidized via their heteroatoms. In this way, the singlet oxygen can exert its oxidative effect on the substrate without losing its excitation energy by colliding with neutral molecules.

Organic peroxides and hydroperoxides having a plurality of peroxy and hydroperoxy groups are also preferred.

The reaction is carried out in any organic solvent suitable for dissolving the substrate to be oxidized. Preferably, a halogenated solvent is used, such as dichloromethane, chloroform, carbon tetrachloride,

192,527 dichloroethane, trichloroethane, tetrachloroethane or various freons. When working with apolar compounds, it is preferable to use an aromatic solvent such as benzene, toluene or xylene.

Advantageously, one of the reagents is dissolved in an organic solvent containing the substrate and the other reagent is added to the reaction mixture. Of course, the reagent that will cause a side reaction by oxidation of the substrate will be added. If both reagents can cause side reactions, it is also possible to add the two reagents simultaneously to the reaction mixture.

A significant advantage of the process according to the invention is that it does not require high temperatures and can be carried out at temperatures between -40 ° C and + 50 ° C. Preferably, the reaction is carried out at room temperature or below. This is also advantageous in terms of suppressing possible side reactions. The reaction mixture is heated to a higher temperature only when required by the solubility of the substrate or by other technological means.

The most important advantage of the present invention is that it allows the homogeneous phase single oxygenation of the singlet compounds.

A further advantage of the invention is that it is highly effective. It is sufficient to use 1-4 equivalents of reagent per mole of substrate. In the prior art processes using inorganic reagents, much more, about one order of magnitude, is required for the oxidation.

The invention is illustrated by the following examples, which are not intended to limit the scope of the invention.

In our experiments, we mainly investigated the production of anthracene endoperoxide, since according to the literature the reaction of antnacene and its 9,10-substituted derivatives in Scheme A can only be performed with singlet oxygen.

In our studies, assuming R-OC1 + R'OOH (ROOR ')> RC1 + ROH + Cri, 1 mole of anthracene can be oxidized with 1-4 equivalents depending on the structure of R, R' or R '. The amount of reactant required depends not only on the structure of the R, R 'or R' group, but also on the solvent.

Example 1

1.7 g (0.01 mol) of atracene are dissolved in 100 cm ^{3 of} chloroform. After complete dissolution, 1.16 g (0.01 mol) of cyclohexyl hydroperoxide are dissolved in the solution. (Compound of formula I). While stirring slowly, a solution of 1.08 g (0.01 mol) of t-butyl hypochlorite in 10 cm ^{3 of} chloroform is added dropwise. After the addition, the reaction mixture was stirred for 10 minutes and then 50 cm ^{3 of} methanol was added. Chloroform was distilled off on a Rotadest apparatus. The residual methyl alcohol precipitates as white powdery crystals. The crystals were filtered off with suction, washed with 10 cm ^{3 of} methyl alcohol and dried in vacuo at room temperature.

The product is anthracene-9,10-endoperoxide. Yield: 1.84 g (0.0087 mol, 87%). M.p. 205-215 (dec).

Example 2

1.7 g (0.01 mol) of anthracene are dissolved in 100 cm @ 3 of chloroform. After judged dissolution, 0.88 g (0.0033 mole) of 1,1'-dihydroperoxide dicyclohexyl peroxide-1 (compound of formula II) is dissolved in the solution. A solution of 1.08 g (0.01 mol) of t-butyl hypoclonite in 10 cm @ 3 of chloroform is added dropwise with constant stirring. After the addition, the reaction mixture was stirred for 1 hour. Add 50 om ³ methyl alcohol. Chloroform was distilled off on a rotary evaporator. The residual methyl alcohol precipitates as white powdery crystals. The crystals are filtered off with suction, washed with 10 cm ^{3 of} methanol and dried in vacuo at room temperature. The product is anthracene -, 10-endoperoxide. Yield: 1.69 g (80.4%).

Example 3

1.7 g (0.01 mol) of anthracene are dissolved in 100 cm ^{3 of} chloroform. After complete dissolution, 1.08 g (0.01 mol) of t-butyl hypochlorite is dissolved in the solution. While stirring, a solution of 2.32 g (0.01 mol) of Ι, Γ-dioxydiocyclohexyl peroxide-1 (compound III) in 15 cm ^{3 of} chloroform is added dropwise. After the addition was complete, the reaction mixture was stirred for 90 minutes, methyl alcohol (50 mL) was added and the chloroform was distilled off in a Rotavade apparatus. The residual methyl alcohol precipitates as white powdery crystals. The crystals were filtered off with suction, washed with 10 cm ^{3 of} methyl alcohol and dried in vacuo at room temperature. The product is anitracene-9,10-endoperoxide. Yield: 1.46 g (69%).

Example 4

1.7 g (0.01 mol) of anthracene are dissolved in 100 cm ^{3 of} chloroform. After complete dissolution, 1.35 g (0.01 mol) of cyclohexyl hypochlorite is dissolved in the solution. While stirring, a solution of 1.38 g (0.01 mol) of benzoeperic acid (compound IV) in 20 cm @ ^{3 of} chloroform is added dropwise. Stir the reaction mixture for 45 minutes after the addition of the brine. Meanwhile, little benzoic acid precipitates out of solution as white crystals. 50 cm ³ of methyl alcohol are added. As a result, even the dissolved benzoic acid precipitates out of solution. The white crystals were filtered off with suction and washed with 15 cm ^{3 of} chloroform. The washings are combined with the reaction mixture. From this, chloroform is distilled off on a Rotadest apparatus. The residual methyl alcohol precipitates as white powdery crystals. The crystals are filtered off with suction, washed with 10 cm @ 3 of methanol and dried in vacuo at room temperature. The product is anthracene-9,10-endoperoxide. Yield:

1.15 g (54%).

5-14. examples

The procedure of Examples 2 and 3 is repeated with the reagents given in the table below. The molar amount and yield of reagents are also shown in the table.

192,527

The number of the example

Example Peroxide has the formula Mole

hypochlorite

Sign Mole Yield

5 2 V 0.01 B 0.01 80 6 2 VII 0.02 THE 0.02 83 7 2 IX 0,015 THE 0,015 87 8 2 X 0.02 B 0.02 73 9 3 VI 0.03 C 0.03 78 10 3 VII 0.01 C 0.01 70 11 3 VIII 0,015 C 0,015 82 12 3 XI 0.01 THE 0.01 87 13 3 XII 0,015 B 0,015 80 14 3 XIII 0.03 C 0.03 73

A - 1,1-Diethyl-propyl-hypochlorite

B = 2-Phenylethyl hypochlorite

C = trifluoroacetyl hypochlorite

Example 15

Preparation of 2-N-piperidinyl-1-phenylethanol A solution of 17.4 g (0.1 mol) of N-piperidino-styrene in cm ^{3 of a} 1: 1 mixture of methyl alcohol and dichloromethane was prepared. The solution was cooled to 5 ° C with stirring and dissolved in t-butyl hypochlorite (16.2 g, 0.15 mol). With constant stirring at the above temperature, ca. A solution of 17.4 g (0.15 mol) of cyclohexyl hydroperoxide in 40 ml of dichloromethane was added dropwise over 1 hour. After the addition was complete, the reaction mixture was stirred at 5 ° C for 15 minutes and then sodium borohydride (8.13 g, 0.22) was added. The reaction mixture was stirred for 5 hours at 5 ° C and then warmed to room temperature. The solvent was evaporated in vacuo and the solid residue was sublimated. Sublimation yields 13.6 g of 2-N-piperidinyl-1-phenylethanol.

M.p. 69.5-70'C, liter 68-69 ° C.

Example 16

The procedure of Example 15 was repeated with 0.15 moles of phenylethyl hypochlorite and 0.15 moles of peroxide VII to give 13 g of product. (8%). M.p. 69.5-70.5 'C.

Example 17

Preparation of benzaldehyde 17 g (0.1 mol) of stilbene are dissolved in cm 'of benzene. The solution was cooled to 5 ° C and 23.55 g (0.15 mol) of 2-phenylethyl hypochlorite was added. A solution of 17.1 g (0.075 mol) of dicyclohexyl dipeoroxide (compound V) in 50 cm @ 3 of benzene is added at 5 'C. After the addition was complete, the reaction mixture was warmed to room temperature and then distilled under a stream of nitrogen. 11.5 g (67%) of benzaldehyde are obtained.

Claims (5)

A process for the double bond oxidation of organic double-bonded organic compounds, wherein the organic double-bonded organic compound is in a homogeneous phase, in an organic solvent, preferably a halogenated hydrocarbon or an aromatic solvent, and reacted with organic peroxide and hydroperoxide. singlet oxy20 gene at -40 ° C to + 50 ° C. Process according to claim 1, characterized in that organic hypochlorite containing oxygen, sulfur and / or halogen as well as organic peroxide or organic hydroperoxide are used in the molecule. The process according to claim 1 or 2, characterized in that (the organic peroxide having several peroxy groups is used as the reagent. θθ The process according to claim 1 or 2, wherein the reagent is an organic hydroperoxide containing a plurality of hydroperoxide groups. 5. A process according to any one of claims 1 to 4, characterized in that the reactions are carried out at room temperature or below.