JP3018263B2 - Method for dehalogenating halogen compounds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dehalogenating a halogen compound using a hydrogen storage alloy.
INDUSTRIAL APPLICABILITY The method of the present invention is useful for synthesizing chemical products used in the fields of food, medicine, agrochemicals and the like.

[0002]

2. Description of the Related Art Many examples of reactions for reducing halogen compounds by hydrogenation have been known for a long time. As a typical example, there is a method of hydrogenating and reducing in a hydrogen atmosphere using a metal catalyst such as palladium, platinum, nickel, cobalt and copper. According to this method, there is an advantage that the reaction can be performed without polluting the reaction system because the operation is simpler than the reaction using another reducing agent, and the product and the catalyst can be easily separated. Of the metal catalysts that can be used at this time, palladium and platinum have relatively high catalytic activities and can perform hydrogenation even at low temperatures and low pressures, but nickel, cobalt, copper, etc. have catalytic activities. Low and often require high temperature and high pressure reactions. On the other hand, industrially, from the viewpoint of running cost when utilizing this reaction, noble metals such as palladium and platinum are expensive even though they can be regenerated, and are not necessarily suitable for use on an industrial scale. I can not say.

[0003] Hydrogen storage alloys, which have been recently developed and are attracting attention for their applications, are currently used in the fields of automobiles, heat pumps, and indoor cooling and heating systems. However, hydrogen storage alloys include, for example, LaNi ₅ , MgNi, Ti
There are many types such as Fe, and the functions such as hydrogen storage amount, discharge pressure, and discharge temperature of the alloy vary greatly depending on the constituent metals thereof. Therefore, selection of the alloy is important in using the alloy.

As examples of the hydrogenation reduction reaction using a hydrogen storage alloy, hydrogen reduction of olefins, hydrogenation of carbon monoxide, and synthesis of ammonia are described in “Hydrogen Storage Alloy Data Book” (published by Yono Shobo 1987). ,further,
The _C18 alcohol production reaction by atmospheric pressure hydrogenolysis of methyl oleate is described in The Chemical Society of Japan (54th Annual Spring Meeting 19
(Held in 1987). Also, hydrogenation of fats and oils (JP-A-63-268799), production of sugar alcohols (Japanese Patent Application No. 2-219100), reduction of disulfide bonds (Japanese Patent Application No.
277808), and the Deprotection Law (Japanese Patent Application No. 2-277809).

However, there is no report on an example in which a halogen compound is dehalogenated using a hydrogen storage alloy.

[0006]

SUMMARY OF THE INVENTION The present invention relates to the dehalogenation of a halogen compound by catalytic hydrogenation.
Since a highly reactive hydrogen storage alloy is used, there is no need to use a conventional catalyst at all, and a large amount of hydrogen discharged from the hydrogen storage alloy can be used at a low pressure. It is another object of the present invention to provide a method for dehalogenating a halogen compound by catalytic hydrogenation.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method for dehalogenating an organic halide by catalytic hydrogenation, wherein M (representing a rare earth element or Ca element) and N
Using a hydrogen storage alloy whose main phase is a compound having a hexagonal CaCu ₅ type crystal structure with i as an essential element, catalytic hydrogenation is performed with hydrogen released from the alloy to dehalogenate halogen compounds. It is characterized by doing.

Hereinafter, the present invention will be described in detail. The organic halide used in the present invention has a general formula of R-X
(R represents an organic atomic group, and X represents a halogen element). The hydrogen storage alloy used in the present invention is hexagonal CaCu ₅ containing M (representing a rare earth element or Ca element) and Ni as essential elements.
The main phase is a compound having a type crystal structure. The CaCu ₅ type crystal phase contained in the hydrogen storage alloy is 50% by weight or more, and the remainder contains intermetallic compounds, impurities, and additional elements other than the main phase as a second phase or a mixed phase. Since these hydrogen storage alloys themselves have a high catalytic activity for the reduction reaction, by appropriately setting the type of alloy used and the temperature conditions for the reduction reaction, 10 kg
Even under a hydrogen gas pressure condition of less than / cm ² , a halogenated compound can be safely dehalogenated at a high reduction rate.

After this hydrogen storage alloy is pulverized, hydrogen is stored in the alloy at a temperature of 0 ° C. or lower under a hydrogen atmosphere for a certain period of time to absorb hydrogen. In the present invention, a reaction solution containing a halogen compound and a hydrogen storage alloy preliminarily storing hydrogen are put into a reaction tank, and after degassing, the reaction solution is adjusted to an appropriate temperature condition while stirring, or the reaction is performed. By encapsulating the hydrogen storage alloy in a tray column capable of cooling the hydrogen storage alloy according to the formula, and circulating the reaction solution maintained at an appropriate temperature condition,
The halogen compound is dehalogenated.

After the reaction, the hydrogen gas and the reaction liquid are recovered, and the hydrogen storage alloy is cooled. This hydrogen storage alloy can be repeatedly used for the next reduction reaction by recycling hydrogen. Note that, in the present invention, due to the characteristics of the hydrogen storage alloy, it is possible to sufficiently perform dehalogenation of a halogen compound under a condition that the hydrogen gas pressure is less than 10 kg / cm ² ,
This is advantageous in terms of maintenance safety of the manufacturing apparatus. Further, as the hydrogen storage alloy, a plating powder, a surface treatment powder, and an encapsulated alloy of copper, silicon, or the like, which are surface-modified for the purpose of improving corrosion resistance, thermal conductivity, and the like, can also be used in the present invention.

[0011]

The present invention will be specifically described below with reference to examples. Example 1 A dead-end type reaction vessel having a capacity of 1 liter is charged with 100 g of a hydrogen storage alloy CaNi _{5 in} which hydrogen is stored in advance. After degassing at 0 ° C and vacuum of 750mmHg for 5 minutes,
A cooled 4% strength by weight solution of 3-chloro-2- (4-isobutylphenyl) propionic acid in 0.01 M NaOH 100
ml was injected into the reaction vessel. Thereafter, the reaction temperature was adjusted to 40 ° C. while stirring. At this time, the hydrogen gas pressure in the reaction vessel was 1.3 kg / cm ² . Two hours later, the main product in the reaction solution was separated by HPLC and confirmed by IR and NMR. As a result, target 2- (4-isobutylphenyl) propionic acid was produced in a yield of 81%. It was confirmed.

Example 2 A dead end type reaction vessel having a capacity of 1 liter is charged with 100 g of a hydrogen storage alloy LaNi _{5 in} which hydrogen is stored in advance. After degassing at 0 ° C and vacuum of 750mmHg for 5 minutes,
100 ml of a cooled 5% by weight solution of 4-chloro-2,6-dihydroxymethylphenol in 0.01 M KOH in methanol was injected into the reaction vessel. Thereafter, the reaction temperature was adjusted to 40 ° C. while stirring. At this time, the hydrogen gas pressure in the reaction vessel was 1.2 kg / cm ² . After 3 hours, H
The main product in the reaction solution was separated by PLC, and IR and NMR
As a result, it was confirmed that the desired 2,6-dihydroxymethylphenol was produced in a yield of 80%.

Example 3 100 g of hydrogen storage alloy LaNi _4.2 Al in which hydrogen was previously stored in a dead-end type reaction vessel having a capacity of 1 liter.
_{Insert 0.8} . After degassing at 0 ° C. and a vacuum of 750 mmHg for 5 minutes, the solution was cooled and cooled to an ethanol solution containing 0.02 M KOH of 4,7-dichlorocarbostyril at a concentration of 8% by weight.
00 ml was injected into the reaction vessel. Thereafter, the reaction temperature was adjusted to 40 ° C. while stirring. At this time, the hydrogen gas pressure in the reaction vessel was 1.3 kg / cm ² . After 5 hours, the main product in the reaction solution was separated by HPLC and confirmed by IR and NMR. As a result, it was confirmed that the desired 7-chlorocarbostyril was produced in a yield of 69%.

Example 4 A dead end type reaction vessel having a capacity of 1 liter is charged with 50 g of a hydrogen storage alloy CaNi _{5 in} which hydrogen is stored in advance. After degassing at 4 ° C and a vacuum of 750mmHg for 4 minutes,
Chilled 2% by weight 4-acetamido-1,2,2
20 ml of ethanol solution of 3-tri-O-acetyl-5-bromocyclopentanetriol was injected into the reaction vessel in the presence of 5 g of an ion exchange resin (Amberlite IR-4B). Thereafter, the reaction temperature was adjusted to 50 ° C. while stirring. At this time, the hydrogen gas pressure in the reaction vessel was 0.9 kg / cm ²
Met. After 3 hours, the main product in the reaction solution was separated by HPLC and confirmed by IR and NMR.
It was confirmed that acetamido-1,2,3-tri-O-acetylcyclopentanetriol was produced at a yield of 89%.

[0015]

As described above, when a halogen compound is dehalogenated using a hydrogen storage alloy according to the present invention, the hydrogen storage alloy itself has a high catalytic ability, so that a conventional catalyst such as nickel is required. 10kg / c hydrogen gas pressure
The halogen compound can be efficiently dehalogenated under a highly safe condition of less than m ² , and can be repeatedly subjected to the reaction. Further, the hydrogen storage alloy can store a larger amount of hydrogen gas than an industrial hydrogen storage device, and can operate at a low pressure as described above. Furthermore, the use of the upflow tray column as described above has an operational advantage that the load on the separation of the reaction solution and the hydrogen storage alloy can be greatly reduced.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI C07C 233/23 C07C 51/377 // C07C 51/377 57/30 57/30 B01J 23/74 321 (72) Inventor Dosako Shunichi 5-15-39-616 Kitaurawa, Urawa City, Saitama Prefecture (72) Inventor Eiji Eiji 1-6-6-802, Irumagawa, Sayama City, Saitama Prefecture (56) References JP-A-2-269797 (JP, A) JP-A-2-107332 (JP, A) JP-A-63-268799 (JP, A) JP-A-59-195501 (JP, A) JP-A-56-133221 (JP, A) JP-A-52-95629 (JP, A) JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C07B 35/06 C07C 37/00 C07C 39/08 C07C 233/23 C07C 51/377

Claims (1)

(57) [Claims] A compound of the general formula RX (R represents an organic atomic group,
When dehalogenating a halogen compound represented by X represents a halogen element, hexagonal CaCu containing M (representing a rare earth element or Ca element) and Ni as essential elements
_A method for dehalogenating a halogen compound, comprising using a hydrogen storage alloy containing a compound having a type ₅ crystal structure as a main phase and catalytically hydrogenating with hydrogen released from the alloy to perform dehalogenation.