JPS5829765A - Manufacture of 3-trichloromethylpyridine and 3-chloro-5-trichloromethylpyridine - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of 3-trichloromethyl- and 3-trifluoromethylpyridine.

2-Chloro-5-trichloromethylpyridine: 2-chloro-5-trifluoromethylpyridine; Compounds such as 2,5-dichloro-5-trichloromethylbilirin and 2,5-dichloro-5-trifluoromethylpyridine ,
A compound with herbicidal activity.

For example, intermediates useful in the production of compounds described in European Patent Publication No. 0001475 ◎ 5-trichloromethyl birilin: 3-trifluoromethylpyridine; 3-chloro-5-trichloromethylpyridine and 3-chloro -5-Trifluoromethylpyridine compounds are useful in preparing some of the above intermediates by chlorination and side chain fluorination.

That is, for example, 5-trichloromethylpyridine can be side chain fluorinated to obtain 3-trifluoromethylpyridine, which can then be selectively chlorinated to obtain 2-chloro-5-trifluoromethylbiriline. (See the European Patent Publication mentioned above). Similarly, 3-chloro-5-
Trichloromethylpyridine and 3-4-5-trifluoromethylpyridine are selectively chlorinated to produce 2,3-dichloro-5-trichloromethylpyridine and 2,5-dichloro-5-trifluoromethylpyridine, respectively. You can get phosphorus.

The present inventors have now developed a method for producing 3-trifluoromethylbiridine from s-methylpyridine by a method that can be easily integrated with subsequent fluorination species.
It has been discovered that trichloromethylpyridine can be selectively produced.

According to the present invention, therefore, 5-methylpyridine and chlorine are reacted in the gas phase at a temperature of 200 to 550"C in the presence of a halomennation catalyst consisting of a metal oxide or a metal halide. A method for producing 3-trichloromethylpyridine is provided.

The process of the invention is particularly applicable when the organic starting material is 3-methylpyridine itself. However, further substituents may be present in the pyridine ring; these substituents may be inert substituents (e.g. chlorine or fluorine atoms) or groups which can themselves be chlorinated 2, e.g. another methyl group. Get a foot.

That is, for example, 5,5-lutidine is chlorinated by the method of the present invention to produce '5,5-bis(trichloromethyl).
- Pyridine can be produced.

Catalysts are usually those considered to be fluorination catalysts, such as chromium, manganese, iron, cobalt, nickel, etc.
The catalyst can also be a metal ordinarily involved in chlorination:
Thus, for example, the catalyst may be a chloride of one or more of the metals mentioned above, or an oxide, chloride or fluoride of one or more of steel, silver, magnesium, calcium, zinc, cadmium and mercury. could be.

The catalyst can be used in fixed bed or fluidized bed form. The metal oxide or halide may be unsupported or supported on a support material such as aluminum fluoride, alumina, silica or silica-alumina support. o If the catalyst is a copper oxide, fluoride or chloride If the starting material is 3-methylpyridine itself, a substantial proportion of 3-chloro-5-trichloromethylbiridine can be formed in the product.

According to another aspect of the invention, therefore, 3-methylpyridine and chlorine are mixed in the gas phase at a temperature of 200-550@C in the presence of a catalyst consisting of a copper oxide, fluoride or chloride. Provided is a method for producing 5-trichloromethylpyridine and/or 5-chloro-5-trichloromethylpyridine, which comprises reacting.

The reaction between 3-methylpyridine and chlorine is 225-525@C
It is preferable to carry out the reaction at a temperature of .

Preferably, the proportion of chlorine Fi5 is at least 6 mol per methyl group of the methylpyridine.

The upper limit of the proportion of chlorine varies depending on the reaction temperature.

Significantly more than 3 moles of chlorine per methyl group of Fi5-methylpyridine (e.g. up to 10 moles of chlorine per methyl group) at the lower limits of the specified reaction temperatures mentioned above.
However, at temperatures of 250° C. or higher, products containing Schif-chloro-5-trichloromethylpyridine can be obtained by using more than about 5 moles of chlorine per methyl group. can be obtained; the proportion of this product increases as the temperature and/or the proportion of chlorine increases.

The reaction of 5-methylpyridine with chlorine is carried out using an inert diluent, preferably nitrogen (e.g. #/mol 5-methylpyridine).
2 to 20 moles of nitrogen), but other inorganic diluents can also be used, as well as organic diluents (e.g. chlorinated hydrocarbons, carbon tetrachloride). The optimum residence time will vary depending on the specific catalyst temperature used and the relative proportions of chlorine and 3-methylpyridine; suitable residence times are typically 1.
~60 seconds ◇ The 3-trichloromethylgyridine and/or 3-chloro-5-trichloromethylpyridine thus obtained can be distilled if desired by conventional methods, e.g. by fractional distillation and/or acid extraction. , can be separated from other reaction products.

Alternatively, the gaseous reaction products are passed to a second reaction zone where 3-trichloromethylpyridine and hydrogen fluoride are reacted in the gas phase in the presence of a fluorination catalyst to produce the corresponding 3-trifluoromethylpyridine can be obtained. Suitable catalysts include the fluorination catalysts already mentioned. The fluorination is preferably carried out at a temperature of 250 to 450@C.

3-Methylpyridine is converted to 5-trifluoromethylpyridine and/or 3-chloro-5-trifluoromethylpyridine by the method described above in which the reaction zone is continuous and the chlorination step and fluorination step are performed separately. The whole process of converting into can be carried out with high selectivity and good conversion.

If desired, the 3-trifluoromethylpyridine obtained in the second reaction zone is separated from the reaction zone and then chlorinated according to the method described in European Patent Publication No. 0 013 474. middle), 2-chloro-
5-trifluoromethylpyridine and/or 2,
6-dichloro-5-trifluoromethylpyridine can be produced. Similarly, the 3-chloro-5-trifluoromethylpyridine produced can be chlorinated to produce 2,3-dichloro-5-trifluoromethylpyridine using the same method as above. However, the production of the additional chlorinated derivatives mentioned above can be carried out by the method of T1, namely:
The gaseous product from the second reaction zone (as described above) is passed to a fifth reaction zone where 5-trifluoromethylpyridine and chlorine are reacted in the gas phase to form a 2-chloro-
5-trifluoromethylpyridine and/or 2,
1,s- by producing 6-dichloro-5-trifluoromethylpyridine, while 5-chloro-5-trifluoromethylpyridine, which in turn produces 2,3-dichloro-5-trifluoromethylpyridine. The production of trifluoromethylpyridine and/or 3-riao-5-trifluoromethylpyridine can be combined.

Examples of the present invention are shown below. In the examples, parts and - are by weight unless otherwise specified.Example 1 Fluid of evaporated 6-methylpyridine (0.0% per hour)
42 mol) with gaseous chlorine and nitrogen at a temperature of 220@C to obtain a mixture containing 4 mol of chlorine and 14 mol of nitrogen per mole of 3-methylpyridine. This mixture was prepared using Inconel (1ncon@l), which had a length of 1 m and an inner diameter of 5 am, and was filled with red into a 41 Il of chromia catalyst.
(The catalyst was previously treated with gaseous hydrogen fluoride).

The catalyst bed temperature was 220°C and the contact time was 8.3 seconds.

The gaseous reaction products were condensed in a water-cooled condenser.

(A fluid of gaseous hydrogen fluoride was introduced into the reaction product fluid between the reactor outlet and the condenser; this hydrogen fluoride acts as a diluent and solvent for the chlorinated products; significant fluoride Formation #'i was not observed) 0 The condensate was diluted with water, neutralized with an aqueous potassium hydroxide solution, and extracted with chloroform. This chloroform solution was subjected to capillary gas-liquid chromatography.

Analyzed by nuclear magnetic resonance and mass spectral.

The main reaction products were as follows: 3-trichloromethylbiridine 56 3-dichloromethylpyridine 14ts5-monochloromethylpyridine 1:1 (unconverted 3-methylpyridine 1o-) slI! Example 2 The same procedure as Example 1 was repeated, except that the reaction temperature was 250'C and the contact time was 7.9 seconds.

The main reaction products were as follows: 3-trichloromethylpyriline 54-3-dichloromethylpyridine 15-5-monochloromethylpyridine 9-2-chloro-5-trichloromethylbiridine 412-chloro- 5-Dichloromethylpyridine 2. Example 3 The same procedure as Example 1 was repeated except that the reaction temperature was 510"C and the contact time was 7.1 seconds.

The main reaction products were: 3-trichloromethylpyridine 48 5-dichloromethylpyridine 9-5-monochloromethylpyridine 7 2-chloro-5-trichloromethylpyridine 101G2-chloro-3- J)
Chloromethylpyridine 4 - Example 4 For comparison, a procedure similar to Example 1 was repeated, except that an empty reactor was used in place of the catalyst bed.

The reaction mixture contained 1 mole of 3-methylbilyrif, 4 J+ chlorine, 8 moles of nitrogen, and 5 moles of hydrogen fluoride (hydrogen fluoride was present as a diluent and solvent for the chlorination product). ; no significant fluorination was observed).

The reaction temperature was 560"C and the contact time was 21 seconds. The main reaction products are as follows: 3-trichloromethylpyridine 2415-dichloromethylpyridine 2012-chloro-5-dichloromethyl Viridine 14% 2-chloro-5-
Trichloromethylpyridine 11 Compared to the previous examples, it can be seen that the production rate of 3-trichloromethylpyridine is lower in this example even when relatively high temperatures and longer contact times are used.

Example 5 Aluminum trifluoride carrier (average particle size 150 m) containing K ferric chloride aqueous solution, based on the weight of the carrier,
-A catalyst containing iron was prepared.

This catalyst (900f) was transferred to a vertical Inconel reactor (diameter 5
After filling the crane (1 length), the temperature was increased to 500＠C with a nitrogen flow.
The mixture was allowed to flow for 1 hour at SOO'C and treated with chlorine (2 mol/h) for 30 minutes.

A fluid consisting of S-methylpyridine (0.42 mol/h) and nitrogen was preheated to 220 CK and reacted in a fluidized bed with chlorine, which was also preheated to 220"C. The reaction mixture was 3- Each mole of methylpyridine contained 5 moles of chlorine and 10 moles of nitrogen.The temperature of the fluidized bed was 31
The temperature was maintained at 0'''C; the residence time in the fluidized bed was 6.3 seconds. Analysis of the reaction products by capillary gas chromatography revealed that the main reaction products were concentrated: 5-Trichloromethylpyridine 53thi3-
Dichloromethylpyridine 2013-Monochloromethylpyridine 8-2-chloro-
5-Trichloromethyl birilin 7 times Example 6 Aluminum fluoride (1000f, "F uniform particle a 1s.

μm) was placed in a vertical reactor (diameter: 50 mm, length: 1 mm), and 32 F anhydrous cuprous chloride powder was added.

The catalyst bed was flushed with nitrogen and heated to 400°C.

After 1 hour, the catalyst was treated with K chlorine (2 mol/h).

After cooling the catalyst bed to 280 °C, a nitrogen stream (220
5-picoline (0.42 mol/h) in a solution (preheated to 220 C) was reacted in a catalyst bed with chlorine, which was also preheated to 220 C. The reaction mixture contained 5 moles of chlorine and 10 moles of nitrogen per mole of 3-methylbilyrif. The temperature of the catalyst bed was maintained at 280"C; the residence time in the catalyst bed was 4
．． It was 2 seconds.

The main reaction products were: 3-trichloromethylpyridine 60 2-chloro-5-trichloromethylpyridine 12 S-chloro-5
-Trichloromethylpyridine 10s 2-chloro-3-trichloromethylpyridine 4m Gaseous reaction product flowing out from the fluidized bed was mixed with gaseous hydrogen fluoride (6-methylpyridine introduced at the beginning of the reaction) preheated to 500''C. 1 mole of ! > 5 moles of HF) and the resulting mixture was placed in a reactor with a diameter of 25 mm filled with the chromia catalyst described in Example 1.
The length of this catalyst bed (1%) K is 350
Holded at °C; residence time was 1.2 seconds. Second
The main products from the reactor were: 3-trifluoromethylpyridine 43962
-Chloro-5-trifluoromethylpyridine 11
Thi-3-chloro-5-trifluoromethylpyridine
9th Example 7 A mixture consisting of 3-methylpyriline, chlorine and nitrogen (
A fluidized bed of a 2-copper-containing chlorination catalyst prepared by impregnating aluminum fluoride with cuprous chloride. (The catalyst was heated to 400 @C before use.
(treated with chlorine by passing a gaseous chlorine stream through for 4 hours).

The fluidized bed was maintained at soo@c. The residence time of the reaction mixture in the fluidized bed (gas velocity, 531 seconds) was approximately 15 seconds.

The gaseous reaction product (containing 3-chloro-5-trichloromethylpyridine) from the fluidized bed was passed through a fixed bed of chromia fluorination catalyst maintained at 330°C without intermediate separation. The reaction product from the pre-fluidized bed was then reacted with gaseous hydrogen fluoride (OHF was introduced at a rate of 5 moles per mole of 5-methylpyridine fed to the fluidized bed). The residence time in the fixed bed was 1 second.

The composition of the product obtained was as follows: 3-chloro-5-trifluoromethylpyridine 15%2
-Chloro-5-trifluoromethylpyridine 28
俤2-chloro-5-trifluoromethylpyridine
9 yen 3-trifluoromethylpyridine 24
5G procedural amendment (method) % formula % 1. Indication of the case 1979 Patent Application No. 79295 2. Name of the invention 3. Person making the amendment Relationship with the case Patent applicant 4, agent 5, amendment order 1972 #-B Month 13 6. Column for the title of the invention in the specification to be amended, application and power of attorney (translation) 7. Contents of the amendment (1. The title of the invention is amended as follows. .

“3-Trichloromethylpyridine and 3-chloro-5
-Production method of trichloromethylpyridine”

Claims (1)

[Claims] t 5-Methylpyridine and chlorine are mixed in a gas phase at a temperature of 200 to
1. A method for producing 3-trichloromethylpyriline, characterized in that the reaction is carried out at a temperature of sso@c in the presence of a halogenation catalyst consisting of a metal oxide or a metal halide. z The method according to claim 1, wherein the catalyst is an oxide of one or more of chromium, manganese, iron, cobalt and nickel, and the fluoride is a chloride. ◇ 1 The catalyst is copper, silver, Magnesium, calcium. A method according to claim 1, comprising one or more oxides, fluorides or chlorides of zinc, cadmium and mercury. 4.3-Methylpyridine and chlorine in a gas phase at 200~
5-trichloromethylpyriline and/or S, characterized in that the reaction is carried out in the presence of a catalyst consisting of copper oxides, fluorides or chlorides at a temperature of 550@C.
- Method for producing chloro-5-trichloromethylpyriline. 5. The method according to any one of claims 1 to 4, wherein the i reaction is carried out at a temperature of 225 to 325°C. 4. Claims 1 to 4, wherein the proportion of chlorine is at least 3 moles per methyl group of 3-methylpyridine.
The method according to any of paragraph 5. l The gaseous reaction product is passed to a second reaction zone where 5-trichloromethylpyridine and hydrogen fluoride are reacted in the gas phase in the presence of a fluorination catalyst to form the corresponding 5-trichloromethylpyridine. A process according to any one of claims 1 to 6 for obtaining methylpyridine @ & passing the gaseous product from the second reaction zone to a third reaction zone where 5- Trifluoromethylpyridine and chlorine are reacted in the gas phase to produce 2-dichloro-5-trifluoromethylpyridine/and/or 2,6-dichloro-
5-trifluoromethylpyridine is produced, while 3
-Chloro-5-trifluoromethylpyridine to 2.3
8. The method according to claim 7, wherein -dichloro-5-trifluoromethylpyridine is produced. 93-chloro-5-trichloromethylpyridine〇