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Method for the c-alkylation of hydroxyl aromatic compounds

A technology of aromatic compounds and hydroxylation, applied in the preparation of organic compounds, chemical instruments and methods, organic compound/hydride/coordination complex catalysts, etc., can solve environmental pollution, alkylation and hydroxylation of aromatic compounds good selectivity difficulties etc.

Inactive Publication Date: 2008-06-18
RHODIA CHEM SA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] However, in practice, achieving favorable yields and / or good selectivities between various alkylated hydroxylated aromatic compounds has often proven difficult
[0007] In addition, the catalysts used in the prior art may cause environmental pollution problems

Method used

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  • Method for the c-alkylation of hydroxyl aromatic compounds
  • Method for the c-alkylation of hydroxyl aromatic compounds
  • Method for the c-alkylation of hydroxyl aromatic compounds

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0101] Synthesis of 4-(tert-butyl)catechol (TBC)

[0102] 50 g of catechol and a catalytic amount of acid were added sequentially to a 170 ml reactor. The reaction mixture was purged with nitrogen, heated to a temperature of 120° C., and then stirred. An isobutene pressure of 1 bar was then applied and the reaction was stopped when approximately 11 g of isobutene had been consumed. The reaction times necessary to consume these 11 grams are listed in Table (1A).

[0103] The reaction performed was as follows:

[0104]

[0105] The results obtained are listed in Table (1A):

[0106] Table (1A)

[0107] catalyst

[0108] The TOF of the catalyst was calculated (turnover frequency = moles of isobutylene converted per mole of catalyst per minute) and listed in Table (1B):

[0109] Table 1B

[0110] catalyst

[0111]From this it is evident that the catalyst of the invention, bis-trifluoromethanesulfonimide (TFSIH) acid, exhibits a particularly high ...

Embodiment 2

[0113] Selectivity of Phenol Alkylation Reaction

[0114] 10 grams of phenol and 6 grams of 2,2,4-trimethylpentene were added to a round bottom flask topped with a reflux condenser and equipped with a temperature sensor. The reaction mixture was heated to 38 °C followed by vigorous stirring. 8 mg of different catalysts were added to the reaction mixture. After one hour, the reaction was stopped, and the reaction product was analyzed.

[0115] The reaction performed was as follows:

[0116]

[0117] The results are listed in Table (2):

[0118] Table 2)

[0119] catalyst

DC 2，2，4-三甲基戊烯 (%)

Pair / o(4) / (3) selectivity

PTSA

45.5

1.27

TA

100

6.52

Trifluoroacetic acid (TFA)

18.2

-

Fuming sulfuric acid: H 2 SO 4 +20% SO 3

41.9

1.45

TFSIH

100

15.41

Methanesulfonic acid (MSA)

38

1.12

h 2 SO 4

47.2

1.37

[012...

Embodiment 3

[0123] Selectivity of Phenol Alkylation Reaction

[0124] The comparative results of the alkylation of phenol with 2,4,4-trimethylpentene (addition time: 60 minutes) catalyzed by 5 different acids (1500 ppm by weight) at 60° C. are listed in the table below:

[0125] table 3

[0126] catalyst

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PUM

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Abstract

The invention relates to a method for the selective C-alkylation in para position of a hydroxyl group of a hydroxylated aromatic compound. The inventive method for the C-alkylation of a hydroxlated aromatic compound having at least one hydrogen atom in para position in relation to the hydroxyl group is characterised by the fact that the compound is placed in the presence of an acid catalyst of formula (I) and a compound leading to the formation of a carbocation in the presence of the acid catalyst. The acid catalyst corresponds to the following formula H-A-[SO2-CpHaXb]n (I) wherein A represents a nitrogen (N) or carbon (C) atom, n is equal to 2 when A is a nitrogen atom, and 3 when A is a carbon atom, X is a halogen atom, p is equal to a number between 1 and 10, b is equal to a number between 3 and 21, and a+b=2p+1.

Description

technical field [0001] The present invention relates to a process for the C-alkylation of hydroxylated aromatic compounds having at least one hydrogen atom in the para position relative to the hydroxyl group. [0002] More specifically, the subject of the present invention is a process for the selective C-alkylation of hydroxylated aromatic compounds in the para position relative to the hydroxyl group. [0003] The present invention relates more particularly to the preparation of 4-(tert-butyl)catechol. Background technique [0004] The alkylation of hydroxylated aromatic compounds has been extensively studied. [0005] Part of this research involves the use of acid catalysts to perform the Friedel-Crafts reaction of these hydroxylated aromatic compounds to increase their yield and / or selectivity. [0006] In practice, however, obtaining favorable yields and / or good selectivities between various alkylated hydroxylated aromatic compounds has often proven difficult. [0007...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C39/08C07C37/14B01J31/10B01J31/18
CPCB01J31/0271C07C37/14C07C37/16B01J2231/4205B01J31/0235B01J31/0224
Inventor J－P·西莫纳托
Owner RHODIA CHEM SA
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