Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
2003-03-11
2004-12-07
Shippen, Michael L. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
Reexamination Certificate
active
06828467
ABSTRACT:
DETAILED DESCRIPTION OF THE INVENTION
1. Technical Field
The present invention relates to a process for producing fluorinated methyl-benzyl alcohols by hydrogenolysis of one hydroxyl group in a fluorinated benzene dimethanol, particularly by hydrogenolysis in a solvent in the presence of a catalyst. Fluorinated methyl-benzyl alcohols are useful as a starting material or an intermediate of medical and pharmaceutical products, agricultural chemicals or other organic compounds. For example, JP-B-1-20143/1989 discloses that fluorinated methyl-benzyl alcohols are reacted with cyclopropane carboxylic acids to obtain ethers having high insecticidal activities.
2. Background Art
For example, the following processes are proposed as the process for producing fluorinated methyl-benzyl alcohols.
1) JP-B-4-6694/1992 discloses a process for producing 4-methyl-2,3,5,6-tetrafluorobenzyl alcohol by reducing 4-methyl-2,3,5,6-tetrafluorobenzoic acid with lithium aluminum hydride in dried ether, and a process for producing 3-methyl-2,4,5,6-tetrafluorobenzyl alcohol by reducing 3-methyl-2,4,5,6-tetrafluorobenzaldehyde with sodium borohydride in methanol.
2) JP-A-63-77829/1988 discloses a process for producing 2-methyl-3,4,5,6-tetrafluorobenzyl alcohol by allowing pentafluorobenzyl alcohol to react with magnesium methyl bromide in tetrahydrofurane.
3) DE-B-3714602 discloses a process for producing 4-methyl-2,3,5,6-tetrafluorobenzyl alcohol by reducing 4-methyl-2,3,5,6-tetrafluoro benzoic acid with sodium borohydride in 1,2-dimethoxyethane.
4) GB-B-2155464 discloses a process for producing 4-methyl-2,3,5,6-tetrafluorobenzyl alcohol by reducing 4-methyl-2,3,5,6-tetrafluorobenzoic acid chloride with sodium borohydride.
However, these processes are not favorable for carrying out industrially because of having problems in that expensive reducing agents are used and strict moisture control for these reducing agents is required.
OBJECT OF THE INVENTION
Accordingly, it is an object of the invention to provide a process for producing a fluorinated methyl-benzyl alcohol, which process can be carried out industrially.
MEANS TO SOLVE THE PROBLEMS
The present invention comprises the following subjects.
[1] A process for producing a fluorinated methyl-benzyl alcohol represented by formula (2):
(wherein m represents an integer of 0 to 3, n represents an integer of 1 to 4, and m+n is an integer of 1 to 4), which process comprises hydrogenolysis of one hydroxyl group in a fluorinated benzene dimethanol represented by formula (1):
(wherein m and n are the same as above).
[2] The process for producing a fluorinated methyl-benzyl alcohol as described in [1], wherein the fluorinated benzene dimethanol is represented by formula (3)
(wherein n represents an integer of 1 to 4), and the corresponding fluorinated methyl-benzyl alcohol is represented by formula (4)
(n is the same as above).
[3] The process for producing a fluorinated methyl-benzyl alcohol as described in [1], wherein the fluorinated benzene dimethanol is tetrafluorobenzene dimethanol represented by formula (5)
and the corresponding fluorinated methyl-benzyl alcohol is tetrafluoromethyl-benzyl alcohol represented by formula (6)
[4] The process for producing a fluorinated methyl-benzyl alcohol as described in [3], wherein the tetrafluorobenzene dimethanol of the formula (5) is 2,3,5,6-tetrafluorobenzene-1,4-dimethanol and the tetrafluoromethyl-benzyl alcohol of the formula (6) is 2,3,5,6-tetrafluoro-4-methyl-benzyl alcohol.
[5] The process for producing a fluorinated methyl-benzyl alcohol as described in any one of [1] to [4], wherein the hydrogenolysis is carried out in a solvent in the presence of a catalyst.
[6] The process for producing a fluorinated methyl-benzyl alcohol as described in [5], wherein the catalyst comprises at least one metal selected from cobalt, iron, copper, nickel, platinum, palladium and rhenium, and the hydrogenolysis is carried out using hydrogen.
[7] The process for producing a fluorinated methyl-benzyl alcohol as described in [6], wherein the catalyst is at least one catalyst selected from the group consisting of a sponge cobalt catalyst, a modified sponge cobalt catalyst, a sponge nickel catalyst and a modified sponge nickel catalyst.
[8] The process for producing a fluorinated methyl-benzyl alcohol as described in [6], wherein the catalyst is a sponge cobalt catalyst or a modified sponge cobalt catalyst.
[9] The process for producing a fluorinated methyl-benzyl alcohol as described in [6], wherein the catalyst is a supported cobalt catalyst, a supported nickel catalyst, a supported palladium catalyst or a supported rhenium catalyst.
[10] The process for producing a fluorinated methyl-benzyl alcohol as described in any one of [5] to [9], wherein the solvent is a single or mixed solvent comprising at least one selected from saturated aliphatic or alicyclic hydrocarbon, aromatic hydrocarbon, alcoholic solvent, ether of aliphatic or alicyclic hydrocarbon and water.
[11] The process for producing a fluorinated methyl-benzyl alcohol as described in [10], wherein the solvent is a single or mixed solvent comprising at least one selected from toluene, xylene, methanol, ethanol, dioxane, dioxolane and water.
[12] The process for producing a fluorinated methyl-benzyl alcohol as described in any one of [1] to [11], wherein the hydrogenolysis reaction is carried out in a hydrogen partial pressure of from 0.05 to 15 MPa.
[13] The process for producing a fluorinated methyl-benzyl alcohol as described in any one of [5] to [12], wherein the amount of the solvent used in the hydrogenolysis reaction is 1 to 20 times by mass based on the fluorinated benzene dimethanol.
[14] The process for producing a fluorinated methyl-benzyl alcohol as described in any one of [6] to [13], wherein the amount of hydrogen used in the hydrogenolysis reaction is 100 to 180% by mole based on the fluorinated benzene dimethanol.
MODE FOR CARRYING OUT THE INVENTION
The present invention is described in detail below.
The present invention relates to a process for producing fluorinated methyl-benzyl alcohols by hydrogenolysis of one hydroxyl group in fluorinated benzene dimethanol, particularly, hydrogenolysis in a solvent in the presence of a catalyst.
The fluorinated benzene dimethanol used as a starting material in the invention can be synthesized by known methods. For example, tetrafluorobenzene dimethanol can be easily prepared by hydrolysis of 2,3,5,6-tetrafluorobenzene dimethanol diacetate, as described in JP-A-1-238555/1989.
As the catalyst used in the invention, metal catalysts are favorable, particularly, a catalyst comprising at least one metal selected from cobalt, iron, copper, nickel, platinum, palladium and rhenium is more favorable.
The catalyst used may be a metal itself, a sponge metal catalyst or a supported catalyst.
The “sponge metal catalyst” used in the present invention is a porous metal catalyst obtainable from an alloy which comprises a metal insoluble in alkali or acid such as nickel or cobalt, and a metal soluble in alkali or acid such as aluminum, silicon, zinc or magnesium to thereby eluting a metal soluble in alkali or acid by use of alkali or acid.
In the present invention, it is preferred to use the sponge cobalt catalyst and sponge nickel catalyst.
Further, a modified sponge metal catalyst obtainable by modification in the presence of a metal other than nickel or cobalt, or a metal oxide thereof may be used in the present invention. Examples thereof may include a modified sponge nickel catalyst modified with molybdenum and a modified sponge cobalt catalyst modified with manganese.
The “supported catalyst” used in the present invention is a catalyst supporting a highly dispersed fine divided metal containing at least
Miura Motoo
Morikawa Kohei
Suyama Yuseki
Shippen Michael L.
Showa Denko K.K.
Sughrue & Mion, PLLC
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