Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
2001-04-24
2002-06-25
Shippen, Michael L. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S677000
Reexamination Certificate
active
06410808
ABSTRACT:
The present invention relates to a method for producing a fluoroalcohol having a 1,1-difluoro-3-hydoxypropyl group or the like.
A fluoroalcohol such as C
a
F
2a+1
(CH
2
)
2
OH (wherein a is an integer of from 1 to 23) having a 1,1-difluoro-3-hydroxypropyl group (—CF
2
CH
2
CH
2
OH) in its molecular structure, is a compound useful as an intermediate for e.g. a water and oil repellent, a surfactant or a release agent.
As a method for producing such a fluoroalcohol, a method is known which comprises reacting C
a
F
2a+1
(CH
2
)
2
X
1
(wherein a is as defined above, and X
1
is a halogen atom) with an alkali metal hydroxide to obtain C
a
F
2a+1
(CH
2
)
2
OH. However, such a reaction has a problem that an olefin compound of the formula C
a
F
2a+1
CH═CH
2
will be formed by a side reaction, whereby the yield of the desired compound decreases. As methods to solve such a problem, the following methods have been proposed wherein a fluoroalkyl iodide or a fluoroalkyl bromide is used as the starting material.
(1) A method wherein it is contacted with fuming sulfuric acid or chlorosulfuric acid to produce a sulfuric acid ester, followed by hydrolysis (JP-B-40-1905, JP-B-58-39135). (2) A method wherein it is contacted with water in the presence of N,N-dimethylformamide (DMF) (JP-B-52-8807). (3) A method wherein it is contacted with water in an organic solvent in the presence of a heavy metal ion catalyst (JP-A-63-22040). (4) A method wherein it is reacted with a betaine compound and water (JP-A-2-142741). (5) A-method wherein it is reacted in a gas phase, if necessary, on a solid acid catalyst having an alkali metal component supported thereon (JP-A-2000-79345).
However, the fuming sulfuric acid or chlorosulfuric acid used in the method (1) has problems such that it is highly corrosive and produces a large amount of byproducts such as dialkylsulfates or chlorides which are hardly hydrolysable. The method (2) has a problem that a formic acid ester of the fluoroalcohol will be formed as a byproduct which is hardly separable by distillation, whereby the purity of the product tends to be low. Further, in order to remove DMF by washing with water, a large amount of waste water will form. There is a further problem that formation of an olefin compound as a byproduct cannot be avoided. The method (3) has a problem that it is a method of using a heavy metal. The method (4) has problems such that the betaine compound is expensive, and recycling is not easy, and it is a method which is disadvantageous from the viewpoint of costs in addition to a problem of the resulting waste liquid. The method (5) has problems such that the useful life of the catalyst is short, and it is difficult to maintain a high conversion and a high selectivity.
The present invention has been made to solve the above problems and provides a method for producing a fluoroalcohol in good yield without using a reagent which is difficult to handle.
The present inventors have found it possible to convert a (—CF
2
(CH
2
)
n
X) group to the desired (—CF
2
(CH
2
)
n
OH) group simply by reacting it with water under certain conditions.
Namely, the present invention provides a method for producing a fluoroalcohol of the following formula 1a, which comprises reacting a compound of the following formula 1 with water in a liquid phase at a temperature of 150° C. or higher under a gauge pressure of 0.4 MPa or higher:
wherein n is an integer of from 1 to 5, X is a chlorine atom, a bromine atom or an iodine atom, p is an integer of at least 1, and R is a p-valent organic group, provided that when p is 1, R may be a hydrogen atom or a halogen atom.
Now, the present invention will be described in detail with reference to the preferred embodiments.
In the compound of the Formula 1, n is preferably 2 from the viewpoint of the availability of the starting material. Further, X is usually a bromine atom or an iodine atom, but is preferably an iodine atom from the viewpoint of the availability of the starting material and the reactivity. Specific examples of the group of the formula —CF
2
(CH
2
)
n
X may be groups shown in the after-mentioned specific examples.
The symbol p represents the number of groups of the formula —CF
2
(CH
2
)
n
X bonded to R. The group of the formula —CF
2
(CH
2
)
n
X is a group bonded to the p-valent organic group. p is preferably 1 or 2. In the Formula 1, R is a p-valent organic group, and the organic group is a group containing at least one carbon atom. R is a group which undergoes no change as between before and after the reaction of the present invention. Accordingly, the p-valent organic group is preferably a group wherein a structure changeable by the reaction of a present invention is not present, and it is preferably a p-valent organic group wherein a structure of the formula —CF
2
(CH
2
)
n
X, an ester bond or an amide bond is not present.
Further, the p-valent organic group is preferably a p-valent saturated hydrocarbon group or a p-valent halogenated saturated hydrocarbon group, and from the viewpoint of the easy availability of the compound of the Formula 1, a p-valent halogenated saturated hydrocarbon group is particularly preferred. The p-valent halogenated saturated hydrocarbon group is preferably a p-valent fluorinated saturated hydrocarbon group, particularly preferably a group having all hydrogen atoms in a p-valent saturated hydrocarbon group substituted by fluorine atoms (i.e. a p-valent perfluoro saturated hydrocarbon group). R may have a straight chain structure or a branched chain structure, or a structure partially having a ring structure.
In a case where p in the Formula 1 is 1, R may be a monovalent organic group, a hydrogen atom or a halogen atom, and it is preferably a monovalent organic group or a halogen atom. As the monovalent organic group, an alkyl group, a halogenated alkyl group or a halogenated (etheric oxygen atom-containing alkyl) group is preferred, and particularly preferred is a perfluoroalkyl group or a perfluoro(etheric oxygen atom-containing alkyl) group.
Further, the compound of the Formula 1 is preferably a compound of the following Formula 2, a compound of the following formula 3 or a compound of the following Formula 4, whereby the objective compound is useful and excellent in the reactivity.
wherein n and X are as defined above, m is an integer of from 1 to 18, preferably an integer of from 6 to 16, k is an integer of from 1 to 10, preferably an integer of from 3 to 8, and r is an integer of from 1 to 10, preferably an integer of from 1 to 3.
Further, X in the Formulae 2 and 4, is preferably a bromine atom or an iodine atom, and X in the Formula 3 is preferably an iodine atom. Further, the group of the Formula C
m
F
2m+1
— in the Formula 2, preferably has a straight chain structure or a branched structure. In the case of a branched structure, the branched portion is preferably present at the terminal portion of said group, and particularly preferably, it essentially has a (CF
3
)
2
CF— structure.
The following compounds may be mentioned as specific examples of the compound of the Formula 1.
CF
3
(CF
2
)
5
CH
2
I,
CF
3
CH
2
CH
2
I,
CF
3
(CF
2
)
7
CH
2
I,
CF
3
(CF
2
)
2
CH
2
CH
2
I,
CF
3
(CF
2
)
5
CH
2
CH
2
I,
CF
3
(CF
2
)
7
CH
2
CH
2
I,
CF
3
(CF
2
)
9
CH
2
CH
2
I,
CF
3
(CF
2
)
11
CH
2
CH
2
I,
(CF
3
)
2
CF (CF
2
)
4
CH
2
CH
2
I,
CF
3
(CF
2
)
7
CH
2
CH
2
Br,
ICH
2
CH
2
(CF
2
)
4
CH
2
CH
2
I,
ICH
2
CH
2
(CF
2
)
6
CH
2
CH
2
I,
BrCH
2
CH
2
(CF
2
)
6
CH
2
CH
2
Br,
F[CF (CF
3
)CF
2
O]
3
CF
2
CF
2
CH
2
CH
2
I.
These compounds are either known compounds or readily available by known production methods disclosed in e.g. J. Org. Chem., 23, 1166 (1958).
In the present invention, the compound of the Formula 1 is reacted with water in a liquid phase at a temperature of 150° C. or higher under a gauge pressure of 0.4 MPa or higher. The reaction of the present invention can be carried out by a method wherein water and the starting material are charged into an autoclave, and they are subjected to certain specific high temperature high pressure conditions,
Furukawa Yutaka
Kasahara Nobuyuki
Oharu Kazuya
Tatematsu Shin
Asahi Glass Company Limited
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Shippen Michael L.
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