# US 5,710,292 A · Process for the selective oxidation of aromatic compounds

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- Number: US 5,710,292 A
- Document ID: US5710292A
- Status: Granted
- Kind: A
- Application number: 08/459,836
- Filed: 1995-06-02
- Granted: 1998-01-20
- Earliest claimed: 1994-06-06
- Assignees: Hoechst Aktiengesellschaft
- Inventors: Wolfgang Anton Herrmann; Joao Domingos Galamba Correia; Richard Walter Fischer
- Web page: https://patentgrep.com/patent/US5710292A

## CPC

- B01J 31/1815: {with more than one complexing nitrogen atom, e.g. bipyridyl, 2-aminopyridine}
- B01J 31/1805: {the ligands containing nitrogen}
- C07B 41/00: Formation or introduction of functional groups containing oxygen
- C07C 37/60: by oxidation reactions introducing directly hydroxy groups on a =CH-group belonging to a six-membered aromatic ring with the aid of other oxidants than molecular oxygen or their mixtures with molecular oxygen
- C07C 41/26: by introduction of hydroxy or O-metal groups
- C07C 46/06: of at least one hydroxy group on a six-membered aromatic ring
- B01J 2231/646: of aromatic or heteroaromatic rings
- B01J 2531/74: Rhenium
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C07B: GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR (preparation of carboxylic acid esters by telomerisation C07C67/47; telomerisation C08F)
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

The invention relates to the use of compounds of the formula Re.sub.a O.sub.b X.sub.c L.sub.d, (I) in which X=F, Cl, Br, I or OH, L=Lewis base, a=an integer 1, 2 or 3 b=zero or an integer from 2 to 9, c=zero or an integer from 1 to 9, d=zero or an integer from 1 to 6, and the sum of a, b and c is such that it is appropriate to the zerovalency or trivalency to heptovalency of the rhenium with the proviso that if b is not equal to zero, b.gtoreq.2.multidot.a, as catalysts for the oxidation of electron-rich aromatic compounds and derivatives thereof and a process for the oxidation of electron-rich aromatic compounds, in which electron-rich C.sub.6 -C.sub.22 aryl compounds and derivatives thereof are oxidized in an organic solvent in the presence of a catalyst of the formula (I) and of a peroxide-containing compound.

## Claims

### Claim 1

A method of using compounds of the formula (I) as catalysts for the oxidation of electron-rich aromatic compounds and derivatives thereof, wherein the formula (I) is:
Re.sub.a O.sub.b X.sub.c L.sub.d (I)
in which
X=F, Cl, Br, I or OH,
L=Lewis base,
a=an integer 1, 2 or 3,
b=zero or an integer from 2 to 9,
c=zero or an integer from 1 to 9,
d=zero or an integer from 1 to 6,
and the sum of a, b and c is such that it is appropriate to the zerovalency or trivalency to heptovalency of rhenium with the proviso that if b is not equal to zero, b.gtoreq.2.multidot.a, comprising the steps of adding the aromatic compounds and catalyst to a solvent and oxidizing the aromatic compounds at the aromatic core.

### Claim 2 (depends on 1)

A method as claimed in claim 1, wherein b is an integer from 2 to 7 and c is zero or 1.

### Claim 3

A process for oxidizing in an organic solvent electron-rich C.sub.6 -C.sub.22 -aryl compounds and derivatives thereof comprising the step of oxidizing the C.sub.6 -C.sub.22 -aryl compounds in the presence of a catalyst of the formula Re.sub.a O.sub.b X.sub.c L.sub.d (I), in which
X=F, Cl, Br, I or OH,
L=Lewis base,
a=an integer 1, 2 or 3,
b=zero or an integer from 2 to 9,
c=zero or an integer from 1 to 9,
d=zero or an integer from 1 to 6,
and the sum of a, b and c is such that it is appropriate to the zerovalency or trivalency to heptovalency of rhenium with the proviso that if b is not equal to zero, b.gtoreq.2.multidot.a, and of a peroxide-containing compound and wherein said C.sub.6 -C.sub.22 -aryl compounds are oxidized at the aromatic core.

### Claim 4 (depends on 3)

The process as claimed in claim 3, wherein the peroxide-containing compound used is hydrogen peroxide.

### Claim 5 (depends on 3)

The process as claimed in claim 3, wherein a C.sub.6 -C.sub.14 -aryl compound is oxidized.

### Claim 6 (depends on 3)

The process as claimed in claim 3, wherein naphthalene and derivatives thereof are oxidized.

### Claim 7 (depends on 3)

The process as claimed in claim 3, wherein 2-methylnaphthalene is oxidized.

### Claim 8 (depends on 1)

The method as claimed in claim 1, wherein the said aromatic compounds comprise C.sub.6 -C.sub.22 -aryl compounds.

### Claim 9 (depends on 1)

The method as claimed in claim 1, wherein said aromatic compounds comprise C.sub.6 -C.sub.14 -aryl compounds.

### Claim 10 (depends on 1)

The method as claimed in claim 1, wherein said aromatic compounds are selected from the group consisting of naphthalene and derivatives thereof.

### Claim 11 (depends on 1)

The method as claimed in claim 1, wherein said aromatic compounds comprise 2-methylnaphthalene.

### Claim 12 (depends on 1)

The method as claimed in claim 1, wherein the catalysts are selected from the group consisting of ReO.sub.2, ReO.sub.3, Re.sub.2 O.sub.7, FReO.sub.3, ClReO.sub.3 and the corresponding Lewis-base L-adducts thereof.

### Claim 13 (depends on 1)

The method as claimed in claim 1, wherein the catalysts comprise ReO.sub.3, Re.sub.2 O.sub.7, or mixtures thereof.

### Claim 14 (depends on 1)

The method as claimed in claim 1, wherein said aromatic compounds are aryl compounds and said aryl compounds are oxidized to the corresponding quinoid systems.

### Claim 15 (depends on 1)

The method as claimed in claim 1, wherein said aromatic compounds are aryl compounds and said aryl compounds are oxidized to the corresponding hydroxyl systems.

### Claim 16 (depends on 1)

The method as claimed in claim 1, wherein said aromatic compound is dissolved in an organic solvent and said catalyst is subsequently added to said organic solvent to form a reaction mixture and said aromatic compound is oxidized at the aromatic core.

### Claim 17 (depends on 16)

The method as claimed in claim 16, wherein the concentration of the dissolved aromatic compounds in said reaction mixture is 0.2 mol in 10-1000 ml of solvent.

### Claim 18 (depends on 16)

The method as claimed in claim 16, wherein said reaction mixture is stirred at a temperature of 10.degree.-100.degree. C.

### Claim 19 (depends on 3)

The process as claimed in claim 3, wherein said aromatic compounds are aryl compounds and said aryl compounds are oxidized to the corresponding hydroxyl systems.

### Claim 20 (depends on 3)

The process as claimed in claim 3, wherein said oxidized aryl compounds are subsequently extracted and dried.