Fluorovinyl ether having terminal oxygen-containing...

Details Fluorovinyl ether having terminal oxygen-containing... Fluorovinyl ether having terminal oxygen-containing...

1998-07-15

2001-02-13

Gerstl, Robert (Department: 1613)

Organic compounds -- part of the class 532-570 series

Organic compounds

Carboxylic acid esters

C560S229000

Reexamination Certificate

active

06187948

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fluorovinyl ether having a terminal oxygen-containing functional group and a process for the preparation of the same. A fluorovinyl ether having a terminal oxygen-containing functional group is useful as a monomer component for the preparation of a fluoropolymer having an oxygen containing functional group.
SUMMARY OF THE INVENTION
JP-A-60-156632, JP-A-60-168711 and U.S. Pat. No. 4,138,426 disclose processes for the preparation of a fluorovinyl ether having a terminal alkoxycarbonyl group of the formula:
CH
3
OCOCF
2
CF
2
[OCF(CF
3
)CF
2
]
n
OCF═CF
2
using CH
3
OCOCF
2
CF
2
OCH
3
as a starting material, and JP-A-5-503935 and U.S. Pat. No. 4,982,009 disclose processes for the preparation of a fluorovinyl ether having a terminal hydroxyl group of the formula:
HOCH
2
CF
2
CF
2
[OCF(CF
3
)CF
2
]
n
OCF═CF
2
by the reduction of the above fluorovinyl ether having a terminal alkoxycarbonyl group with sodium borohydride.
JP-A-52-3017, JP-A-58-85832, JP-B-61-21457 and JP-B-61-21458 disclose processes for the preparation of a fluorovinyl ether having a terminal alkoxycarbonyl group: CH
3
OCOCF
2
CF
2
CF
2
O—CF═CF
2
, and a fluorovinyl ether having a terminal hydroxyl group:
HOCH
2
CF
2
CF
2
CF
2
OCF═CF
2
.
The above processes have their own problems. For example, the processes disclosed in JP-A-60-156632, etc. have a drawback that it is difficult to obtain the starting material, while the processes disclosed in JP-A-52-3017, etc. necessitate a number of reaction steps. In addition, the both processes should use SO
3
the handling of which is difficult.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a novel process for the preparation of a fluorovinyl ether having a terminal oxygen-containing group, which does not suffer from the problems of the above conventional processes.
Another object of the present invention is to provide a fluorovinyl ether having a new chemical structure which has not been able to be prepared by the conventional processes.
Firstly, the present invention provides a fluorovinyl ether of the formula:
R
1
CO(OCH
2
CF
2
CO)
k
(OCH
2
CF
2
CF
2
)
m
[OCF(CF
3
)CF
2
]
n
OCF═CF
2
  (I)
wherein R
1
is an aliphatic or halogenated aliphatic group having 1 to 8 carbon atoms or an aromatic group which may optionally have at least one substituent, k is an integer of at least 0, m is an integer of at least 1, and n is an integer of at least 0, preferably k is an integer of 0 to 10, m is an integer of 1 to 5, and n is an integer of 0 to 10.
Secondly, the present invention provides a process for the preparation of a fluorovinyl ether having a terminal oxygen-containing group of the formula (I), comprising the steps of:
reacting hexafluoropropeneoxide with an acid fluoride of the formula:
R
1
CO(OCH
2
CF
2
CO)
k
(OCH
2
CF
2
CF
2
)
m−1
OCH
2
CF
2
COF  (II)
wherein R
1
, k and m are the same as defined above, in the presence of a metal fluoride to obtain an acid fluoride of the formula:
R
1
CO(OCH
2
CF
2
CO)
k
(OCH
2
CF
2
CF
2
)
m
[OCF(CF
3
)CF
2
]
n
OCF(CF
3
)COF  (III)
wherein R
1
, k, m and n are the same as defined above,
pyrolyzing the acid fluoride of the formula (III) as such, or after the conversion of the acid fluoride of the formula (III) to a corresponding carboxylate salt through a reaction with a metal salt, to obtain the compound of the formula (I).
Thirdly, the present invention provides a process for the preparation of a fluorovinyl ether having a terminal hydroxyl group of the formula:
H(OCH
2
CF
2
CO)
k′
(OCH
2
CF
2
CF
2
)
m
[OCF(CF
3
)CF
2
]
n
OCF═CF
2
  (IV)
wherein m and n are the same as defined above, and k′ is an integer of 0 to k, comprising the step of converting the terminal acyloxy group of a fluorovinyl ether having a terminal oxygen-containing functional group of the formula (I) to a hydroxyl group by hydrolysis to obtain the compound of the formula (IV).
The process of the present invention uses an acid fluoride of the formula (II) as a starting material. When this acid fluoride is used as a starting material, the fluorovinyl ether of the present invention can be prepared from a readily available starting material in a fewer reactions steps. An acyl group functions as a protecting group of a hydroxyl group, since the hydroxyl group reacts with a fluorovinyl ether group.
DETAILED DESCRIPTION OF THE INVENTION
The acid fluoride used as a starting material in the process of the present invention, which is represented by the formula (II), is preferably a halogenated carboxylic acid ester-acid fluoride which is prepared by reacting a halogenated carboxylic acid salt with 2,2,3,3-tetrafluorooxetane as disclosed in JP-A-61-130254.
The group R
1
having the larger number of halogen atoms is more preferable. Thus, preferable examples of the group R
1
are a perfluoroalkyl group having 1 to 8 carbon atoms, &ohgr;-H-perfluoroalkyl group having 1 to 8 carbon atoms, &ohgr;-Cl-perfluoroalkyl group having 1 to 8 carbon atoms, and Cl(CF
2
CFCl)
p
CF
2
— wherein p is 1, 2 or 3, etc.
Examples of the aromatic group are phenyl, 1-naphthyl, 2-naphthyl, 2-furyl, 3-furyl, 2-thienyl, 3-thienyl, etc., and examples of substituents present on the aromatic rings are a methyl group, a methoxy group, an acetyl group, a nitro group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, etc.
The reaction between hexafluoropropeneoxide (hereinafter referred to as “HFPO”) and the acid fluoride of the formula (II) may be carried out by a process which is used for reacting a general acid fluoride and HFPO.
As a solvent, any solvent that does not react with the acid fluoride (II) can be used. Glymes are preferable. The amount of a solvent is not limited. Usually, the amount of a solvent is 0.5 to 5 times the volume of the acid fluoride (II).
The kind of a metal fluoride is not limited. Preferable examples of metal fluorides are alkali metal fluorides such as otassium fluoride and cesium fluoride.
The amount of a metal fluoride is not limited either. referably, the metal fluoride is used in an amount of 0.9 to 1.2 moles per one mole of the acid fluoride (II).
The reaction temperature is not critical. Usually, the reaction temperature is maintained in the range between −60° C. and −20° C. when HFPO is added.
In an optional step, an acid fluoride of the formula (III), which has been formed by the reaction of the acid fluoride (II) and HFPO, maybe converted to a carboxylate salt by various methods, for example, neutralization with an alkali or a carbonate salt. In particular, the transfer reaction of an acid fluoride moiety with a metal salt is preferable for avoiding the hydrolysis of the carboxylate ester moiety.
The kind of a solvent used in the step for forming the carboxylate salt is not limited. Glymes are preferably used like in the reaction with HFPO. The amount of a solvent is not limited either. Preferably, a solvent is used in an amount of 0.5 to 5 times the volume of the acid fluoride of the formula (III).
A metal salt may be any one of organic and inorganic salts of oxyacids. In particular, salts of aliphatic carboxylic acids having 1 to 8 carbon atoms, salts of halogenated aliphatic carboxylic acids having 1 to 8 carbon atoms or salts of aromatic carboxylic acids having 6 to 8 carbon atoms (in the aromatic moiety) are preferable. The kind of a metal in the metal salt is not limited. Alkali metals are preferable.
The amount of a metal salt is at least 0.9 mole, preferably 1.0 to 1.2 moles, per one mole of the acid fluoride (III).
When the acid fluoride (III) as such or its carboxylate salt is pyrolyzed, a solvent is not always used. When a solvent is used, one that does not react with the fluorovinyl ether is used. Glymes are preferable, like in the previous reaction.
The amount of a solvent is not limited. After the solvent and a by-produced acid fluoride are removed from the reaction mixture from the pre

Affiliated with

Also associated with

Rating

Fluorovinyl ether having terminal oxygen-containing... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Fluorovinyl ether having terminal oxygen-containing..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fluorovinyl ether having terminal oxygen-containing... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2612169