Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acids and salts thereof
Patent
1998-06-12
2000-12-26
Killos, Paul J.
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acids and salts thereof
562405, C07C 6510
Patent
active
061662461
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a novel 4-fluorosalicylic acid derivative which can be easily converted to a 3-fluorophenol derivative very useful as an intermediate for liquid crystal, recording material, medicine, agricultural chemical, etc., as well as to a process for production of said 4-fluorosalicylic acid derivative.
BACKGROUND ART
The 4-fluorosalicylic acid derivative of the present invention is a novel compound which has been unknown and which is not described in any literature. It has been also unknown that the 4-fluorosalicylic acid derivative can become a useful raw material for producing a 3-fluorophenol derivative useful as an intermediate for liquid crystal [refer to Japanese Patent Application Kokai (Laid-Open) No. 291899/1995 and Japanese Patent Application Kokai (Laid-Open) No. 10847/1995], recording material [refer to Japanese Patent Application Kokai (Laid-Open) No. 264587/1991], agricultural chemical [refer to Japanese Patent Application Kokai (Laid-Open) No. 345740/1994], medicine [refer to Japanese Patent Application Kokai (Laid-Open) No. 309837/1995], etc.
The objects of the present invention are to provide a novel 4-fluorosalicylic acid derivative which can be easily converted to a 3-fluorophenol derivative useful as mentioned above, and a process for producing the 4-fluorosalicylic acid derivative.
The present inventors made a study in order to achieve the above objects. As a result, the present inventors found out that a useful 3-fluorophenol derivative can be easily produced by decarboxylation of a 4-fluorosalicylic acid derivative and that the 4-fluorosalicylic acid derivative used as a raw material in the decarboxylation is a novel compound not described in any literature and is useful not only as an intermediate in production of the 3-fluorophenol derivative but also in production of liquid crystals, etc. The present invention has been completed based on the above finding.
DISCLOSURE OF THE INVENTION
The present invention provides a 4-fluorosalicylic acid derivative represented by the following general formula (1): ##STR2## (wherein X.sup.1, X.sup.2 and X.sup.3 are each independently a hydrogen atom or a halogen atom with a proviso that there is no case in which all of X.sup.1, X.sup.2 and X.sup.3 are hydrogen atoms or fluorine atoms simultaneously).
The present invention also provides a process for producing a 4-fluorosalicylic acid derivative represented by the following general formula (1): ##STR3## (wherein X.sup.1, X.sup.2 and X.sup.3 are each independently a hydrogen atom or a halogen atom with a proviso that there is no case in which all of X.sup.1, X.sup.2 and X.sup.3 are hydrogen atoms or fluorine atoms simultaneously), which process comprises reacting a 2,4-difluorobenzoic acid derivative represented by the following general formula (4): ##STR4## (wherein X.sup.1, X.sup.2 and X.sup.3 are each independently a hydrogen atom or a halogen atom with a proviso that there is no case in which all of X.sup.1, X.sup.2 and X.sup.3 are hydrogen atoms or fluorine atoms simultaneously) with an alkali metal hydroxide in at least one solvent selected from the group consisting of a compound represented by the following general formula (2): ##STR5## [wherein A is a group --CH.sub.2 -- or a group --NR'-- (wherein R' is a lower alkyl group); R is a lower alkyl group; W is a lower alkyl group; X is a hydrogen atom or a lower alkyl group when A is a group --CH.sub.2 --, and is a lower alkyl group when A is a group --NR'--; W and X may combine with each other to form a lower alkylene group and become a 5- to 7-membered ring together with --N--C--A--] and a compound represented by the following general formula (3): independently a lower alkyl group; Y and Z may combine with each other to form a lower alkylene group and become a 4- to 6-membered ring together with a group --SO-- or a group --SO.sub.2 --).
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention is hereinafter described in detail.
The compound of the present invention is a 4-fluorosalicylic
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Ihara Chemical Industry Co. Ltd.
Killos Paul J.
Oh Taylor V.
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