Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acid esters
Patent
1983-09-12
1985-07-23
Killos, Paul J.
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acid esters
562474, C07C 6976
Patent
active
045310092
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to a process for preparing .alpha.,.omega.-bis(2-chlorophenoxy)alkane-4,4'-dicarboxylic acid or its lower alkyl ester in high yield.
DESCRIPTION OF THE PRIOR ART
It is known that a polyester is obtained by condensation reaction of .alpha.,.omega.-bis(2-chlorophenoxy)alkane-4,4'-dicarboxylic acid or its derivatives represented by the following formula ##STR1## (wherein R denotes a radical selected from hydrogen and lower alkyl radical, n denotes an integer of 2,4, and 6), 1795/74 and 13238/74).
In the prior art, the above mentioned chlorinated dicarboxylic acid was prepared by a process comprising chlorinating p-hydroxy benzoic acid or its ester, and reacting the resulting product with .alpha.,.omega.-dihalogeno polymethylene(Published Examined Japanese Patent Application No. 11899/75). ##STR2##
However, in the ether forming reaction of this prior art, when .alpha.,.omega.-dibromo polymethylene is used as a reactant, the yield is 60 to 75 percent (refer to the Examples of Published Examined Japanese Patent Application No. 11899/75), but the following problem has existed. That is, since NaBr which is by-produced in the reaction causes the severe corrosion of the metal, the usual reaction vessel made of stainless steel was not able to be used.
Moreover, .alpha.,.omega.-dibromo polymethylene is expensive. On the other hand, when .alpha.,.omega.-dichloro polymethylene is used as a starting material, the yield is at most 40 percent (refer to Comperative Examples in the present invention). Therefore, since the total yields of the halogenation reaction and the ether forming reaction become even lower, the preparation method is disadvantageous to adapt for industrial use.
Accordingly, the object of the invention is to provide an economical process for preparing pure .alpha.,.omega.-bis(2-chlorophenoxy)alkane-4,4'-dicarboxylic acid or its lower alkyl ester in high yield.
The foregoing object is effectively accomplished by heating p-hydroxybenzoic acid or its lower alkyl ester with alkylene dichloride, to obtain .alpha.,.omega.-bis(phenoxy)alkane-4,4'-dicarboxylic acid or its lower alkyl ester (ether forming reaction), and reacting it with chlorine in the presence of a particular solvent(chlorination reaction).
Typical reactions are: ##STR3##
DISCLOSURE OF THE INVENTION
The present invention is a process for preparing .alpha.,.omega.-bis(2-chlorophenoxy)alkane-4,4'-dicarboxylic acid or its lower alkyl ester which comprises reacting .alpha.,.omega.-bis(phenoxy)alkane-4,4'-dicarboxylic acid or its lower alkyl ester with chlorine in the presence of a solvent selected from the group consisting (a) lower fatty acid having 2 to 6 carbon atoms, (b) hydrocarbon chloride having 1 to 8 carbon atoms, and (c) carbon chloride having 1 to 2 carbon atoms, in the absence or presence of a catalyst at a lower temperature than boiling point of said solvent.
Furthermore, the present invention is a process wherein .alpha.,.omega.-bis(phenoxy)alkane-4,4'-dicarboxylic acid or its lower alkyl ester obtained by heating p-hydroxybenzoic acid or its lower alkyl ester with alkylene dichloride is used as a starting material.
In general, when a complicated compound having a high molecular weight is chlorinated, many by-products are produced lowering the purity or yield of the product, since the complicated compound has various positions capable of being chlorinated. Therefore the chlorination reaction is usually carried out in a simple compound having a low molecular weight, prior to the other reaction.
However, in the present invention, it has found that .alpha.,.omega.-bis(2-chlorophenoxy)alkane-4,4'-dicarboxylic acid or its lower alkyl ester can be prepared by selective mono-chlorination in the ortho-position to the neighboring oxygen atom of the aromatic ring of the .alpha.,.omega.-bis(phenoxy)alkane-4,4'-dicarboxylic acid or its lower alkyl ester.
PREFERRED EMBODIMENT OF THE INVENTION
Hereinafter, the present invention is described in detail.
.alpha.,.omega.-bis(phenoxy)alkane-4,4'-dica
REFERENCES:
patent: 3426035 (1969-02-01), Bremmer
Inoue Toshihide
Komatsu Hideo
Killos Paul J.
Miller Austin R.
Toray Industries Inc.
LandOfFree
Process for preparing .alpha.,.omega.-bis(2-chlorophenoxy)alkane does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for preparing .alpha.,.omega.-bis(2-chlorophenoxy)alkane, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for preparing .alpha.,.omega.-bis(2-chlorophenoxy)alkane will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-635328