Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
1999-09-10
2001-01-23
Padmanabhan, Sreeni (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S411000, C568S419000, C570S168000
Reexamination Certificate
active
06177595
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements in a process of producing chlorofluoroacetones, particularly 3,3-dichloro-1,1,1-trifluoroacetone and 1,1,3,3-tetrachloro-1-fluoroacetone, which are useful as intermediate materials of medicines and agricultural chemicals and as reagents for introducing fluorine-containing groups.
2. Description of the Prior Art
A variety of processes of producing chlorofluoroacetones have been hitherto proposed and put into practical use. For example, an English translation (pages 241 to 245) of Doklady Akademii Nauk SSSR, Vol. 307, No. 6, pages 1385 to 1390, August 1989 discloses that 3,3-dichloro-1,1,1-trifluoroacetone is synthesized from 3,3,3-trichloro-1,1,1-trifluoropropane-2-one in an anhydrous solvent, through an Al-enolate intermediate, by using a mercury compound as a catalyst. Additionally, Japanese Patent Provisional Publication No. 10-287609 discloses that pentachloroacetone is fluorinated by hydrogen fluoride in a liquid phase in the presence of an antimony pentachloride thereby to form 3,3-dichloro-1,1,1-trifluoroacetone. Further, Japanese Patent Provisional Publication No. 11-1451 discloses that pentachloroacetone is fluorinated in a gas phase in the presence of a fluorination catalyst thereby to form 3,3-dichloro-1,1,1-trifluoroacetone.
The technique disclosed in the English translation of Doklady Akademii Nauk SSSR not only requires to maintain a production process strictly in an anhydrous condition but also uses mercury, which is problematic in case of employing the technique in an industrial scale. The technique disclosed in Japanese Patent Provisional Publication No. 10-287609 uses the antimony pentachloride catalyst and therefore provides corrosion of a reactor, which is problematic as an industrial process. Further, by the technique disclosed in Japanese Patent Provisional Publication No. 11-1451, a relatively large amount of reduction products such as 3-chloro- 1,1,1 -trifluoroacetone and 1,1,1 -trifluoroacetone is produced.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved process of producing chlorofluoroacetones, which can overcome drawbacks encountered in the above conventional techniques.
Another object of the present invention is to provide an improved process of producing chlorofluoroacetones, which is suitable for being carried out in an industrial scale.
A further object of the present invention is to provide an improved process of producing chlorofluoroacetones, which is high in yield of chlorofluoroacetones while suppressing corrosion of a reactor in such an extent as to be allowable.
A process according to the present invention is for producing chlorofluoroacetones represented by a general formula
where X represents independently chlorine atom or fluorine atom. The process comprises fluorinating in a liquid phase pentachloroacetone by hydrogen fluoride in the presence of a catalyst containing at least one metal selected from the group consisting of metals of the groups 4, 5, 6, 7, 8, 14 and 15 of the periodic table, the metals excluding antimony.
According to the production process of the present invention, objective chlorotrifluoroacetone, particularly 3,3-dichloro- 1,1,1 -trifluoroacetone and 1,1,3, 3-tetrachloro- 1-fluoroacetone, can be effectively produced from the corresponding organic chlorinated compound under a single step reaction.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, a process of producing chlorofluoroacetones represented by the following general formula (1):
where X represents independently chlorine atom or fluorine atom. The process comprises fluorinating in a liquid phase pentachloroacetone by hydrogen fluoride in the presence of a catalyst containing at least one metal selected from the group consisting of metals of the groups 4, 5, 6, 7, 8, 14 and 15 of the periodic table, the metals excluding antimony.
According to the production process of the present invention, chlorine atoms in —CCl
3
group of pentachloroacetone are successively substituted with fluorine atom, and therefore intermediately produced lower fluorine compounds may be used in place of pentachloroacetone, which is also a mode of the present invention.
Chlorofluoroacetones represented by the general formula (1) are 3,3-dichloro- 1,1, 1-trifluoroacetone, 1,3,3-trichloro-1,1-difluoroacetone and 1,1,3,3-tetrachloro- 1-fluoroacetone, and preferably 3,3-dichloro- 1,1,1-trifluoroacetone and/or 1,1,3,3-tetrachloro- 1-fluoroacetone.
The production process according the present invention can be carried out as a batch process, a half-batch process in which reaction is conducted removing only products from a reactor, and a continuous or flowing process. While discussion will be made mainly on reaction in the batch process hereinafter, it will be appreciated that reaction conditions (discussed below) for the reaction in the batch process may be applicable to other processes upon being modified to such extents as to be readily adjustable by persons skilled in the art.
Pentachloroacetone used as a starting (raw) material in the production process of the present invention can be synthesized by known methods, for example, usually by chlorinating acetone with chlorine in the presence of light or a catalyst such as metal chloride, acid, metal-organic acid salt, or by oxidizing chlorinated alcohol.
The catalyst to be used in the production process of the present invention includes at least one metal compound containing one of metals of the groups 4, 5, 6, 7, 8, 14 and 15 of the periodic table, the metals excluding antimony. Antimony is high in fluorination activity so that reaction can proceed within a short time; however, it is high in corrosion action to a metal reactor and therefore is not preferable to be used as catalyst. It is preferable to use for the catalyst tin, titanium, molybdenum, tantalum, lead, manganese, niobium, bismuth, tungsten and/or iron, in which tin is more preferable. Specifically, it is preferable to use as the catalyst only tin compound, or a combination (mixture) of tin compound and at least one of compounds of titanium, molybdenum, tantalum, lead, manganese, niobium, bismuth, tungsten and iron, in which the combination of tin compound and titanium compound, or the combination of tin compound and niobium compound is more preferable.
According to kinds of the catalyst, modes of reaction in the production process change. In case of using the catalyst of only tin compound, reaction proceeds relatively gently so that a relatively long reaction time is required, providing advantage of producing less by-products. In case of using the catalyst of the combination of tin compound and titanium compound or the combination of tin compound and niobium compound, formation of decarbonylation product is found while providing advantage of completing reaction within a relatively short time. Additionally, it is more preferable to use only tin compound mainly in case of producing 1,1,3,3-tetrachloro-1-fluoroacetone. In any cases of the above-mentioned, requirements for industrial production processes can be sufficiently met.
It is assumed that the metal compound serving as the catalyst takes the form of a specified compound according to conditions of a reaction system of the fluorination, and therefore it is unnecessary that the metal compound in the form of a specified compound when supplied into a reactor. Accordingly, the metal compound to be supplied to the reactor is in the form of chloride, bromide, fluoride, oxide, nitrate, sulfate, carbonate and/or the like of the above-mentioned metal, in which chloride or fluoride is preferable. It is preferable that the metal of the metal compound is one in the state of higher valence which are usually takable, such as tin having the valence of 4, titanium having the valence of 4, molybdenum having the valence of 5, tantalum having the valence of 5, lead having the valence of 4, manganese having the valence of 4, niobium having the valence of 5, bismuth having the valence of 4, t
Goto Yoshihiko
Nadano Ryo
Nakamichi Toshihiro
Sakaya Takashi
Suenaga Shigeru
Central Glass Company Limited
Evenson, McKeown, Edwards & Lenahan P.L.L.C.
Padmanabhan Sreeni
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