JPS584700B2 - Transesterification method using alkoxo copper and phenoxo copper compounds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION It is industrially important to exchange carboxylic acid esters and carbonate esters with new esters by exchange reactions with alcohols.

Conventionally, acids, alkalis, and various typical metal alkoxides have been used as catalysts for this transesterification reaction.

Among these, typical metal alkoxides are particularly important catalysts for transesterification in non-aqueous systems, and are widely used in the synthesis of polyesters.

An object of the present invention is to provide a method for carrying out transesterification using a copper complex having a tertiary phosphine in which an alkoxine group or a phenoxo group is bonded to copper as a ligand.

That is, the above-mentioned copper compound under non-aqueous mild conditions,
Aluminum alkoxide, which is already used industrially,
This is because it has a higher catalytic activity than other metal alkoxides such as titanium alkoxide.

For this reason, the method of the present invention uses a compound in which an alkoxo group or a phenoxo group is bonded to copper as a catalyst, and in the presence of alcohol, phenol, or substituted phenol, the alkoxy groups of carboxylic acid esters, phosphite esters, and dialkyl carbonate esters are Alternatively, it is characterized by converting an aryloxy group into another alkoxy group or an aryloxy group.

According to the method of the present invention described above, there is an advantage that ester exchange is carried out extremely efficiently and reliably.

Next, general embodiments of the present invention will be described.

First, the ester and alcohol are placed in a container, mixed, and then a catalytic amount of an alkoxo copper compound or a phenoxo copper compound is added and stirred.

After a predetermined period of time has elapsed, the reaction product is taken out.

Example 1 20 mmol of methyl methacrylate and 400 mmol of ethyl alcohol were dissolved in 10 ml of tetrahydrofuran, and 200 ~ phenoxobis(triphenylphosphine) copper C6H5OCu (PPhs) was added as a catalyst.
2(PPh3)triphenylphosphine) and 5
Stir at 0-60°C for 5 hours.

As a result, 94% of the raw material methyl methacrylate was converted to ethyl methacrylate.

By similar methods, alkoxy groups or aryloxy groups of various carboxylic esters including saturated carboxylic esters, unsaturated carboxylic esters, and aromatic carboxylic esters are converted to other alkoxy groups or aryloxy groups.

Examples are shown in the table below.

In this table, when C6H5OCu(PPh3)2 is used as a catalyst, toluene is used as the reaction solvent, and when other copper catalysts are used, the reaction is conducted without a solvent.

Example 2 200 mmol of trimethyl phosphite was mixed, and 2
00 mg of ethoxobis(triphenylphosphine)copper C2H5OCu(PPh3)2 was added as a catalyst and heated at 0 °C.
Stir for 12 hours.

Through this operation, the raw material trimethyl phosphite was reduced to 12 mmo.
l (yield=60%) of triethyl phosphite, 7.4 mm
ol (yield = 37%) of methyl diel phosphite and 0
．． Converted to 4 mmol (yield=2%) of diethylmethyl phosphite.

Example 3 20 mmol of dimethyl carbonate was mixed and stirred at 0° C. for 12 hours using 200 mg of C2H50Cu(PPh3)2 as a catalyst.

Through this operation, the raw material dimethyl carbonate was 12.6 mmol.
(yield=63%) of diethyl carbonate and 6.8 mmol (yield=34%) of methylethyl carbonate.

Claims (1)

[Claims] 1 Using as a catalyst a copper complex having a tertiary phosphine, in which an alkoxo group or a phenoxo group is bonded to copper, as a ligand,
Copper alkoxo, characterized in that the alkoxy or aryloxy groups of carboxylic esters, phosphites and dialkyl carbonates are converted into other alkoxy or aryloxy groups in the presence of alcohols, phenols or substituted phenols. and transesterification using phenoxo copper compounds.