* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
Reference：
[1] Journal of the Chemical Society, Perkin Transactions 1, 1989, # 2, p. 283 - 287
3
[ 609-71-2 ]
[ 72648-12-5 ]
Yield
Reaction Conditions
Operation in experiment
72%
at 160℃; for 5 h;
A mixture of 2-hydroxypyridine-3-carboxylic acid (100.0 mmol), phenylphosphonic dichloride (33.0 mmol), and phosphorus pentachloride (330.0 mmol) was slowly heated to 160 °C and the by-product (POCl3) was distilled. Then the mixture was stirred at the same temperature for 5 h. Thin-layer chromatographic (TLC) analysis showed the reaction had been finished. The POCl3 was evaporated in vacuum; the residue was poured into ice water, neutralized with saturated aqueous sodium carbonate solution, and extracted with acetic ether. The organic layer was washed with water, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure, and the obtained crude product was distilled or purified with silica-gel chromatography.
With chlorine;pelletized catalyst TOSOH HSZ-690 HOD (SAR 203) with a silica binder; at 350℃;Gas phase;Product distribution / selectivity;
Example 2; The pelletized catalyst, TOSOH HSZ-690 HOD (SAR 203) with a silica binder, was ground to a coarse powder and screened to obtain a uniform size of 1-2 mm in diameter. A weight of 0.26 g of catalyst was charged into the reactor tube and glass wool (Pyrex) was used to secure it in place. Operating at a chlorine feed of 5 cc/min, a beta-picoline feed rate of 0.13 mg/min (10 cc/min N2 with a chiller temperature of 10 C.), the reagents were fed to the reactor at an initial temperature of 250 C. The system was initially ramped up to 325 C. and allowed to stablize. Under these conditions the product gases were 18.5% 3-trichloromethylpyridine (beta-tri ) and 65.4% beta-2-tet. When the system was allowed to stabilized at 350 C. the amount of beta-tri in the product gases was reduced to 2.6% and the conversion to beta-2-tet increased to 68.6% (see Table 2).; Example 3; The catalyst, TOSOH HSZ-690 HOD (SAR 203) with the silica binder, was sized to a uniform particle size of 1-2 mm in diameter. A weight of 0.26 g of catalyst was charged into the reactor tube and glass wool (Pyrex) was used to secure it in place. The reactor temperature was initially set to 250 C. prior to flowing chlorine at a rate of 5 cc/min. The beta-picoline feed rate was set to 0.13 mg/min (N2 flow 10 cc/min, chiller at 10 C.), while the reactor oven was ramped up to 350 C. over a one hour time period. At 350 C. the amount of beta-2-tet observed in the product gases was 65.6% (see Table 2).; Example 4; The catalyst, TOSOH HSZ-690 HOD (SAR 203) with the silica binder, was sized to a uniform particle size of 1-2 mm in diameter. A weight of 0.51 g of catalyst was charged into the reactor tube and glass wool (Pyrex) was used to secure it in place. The reactor temperature was initially set to 250 C. prior to flowing chlorine at a rate of 5 cc/min. The beta-picoline feed rate was set to 0.13 mg/min (chiller at 10 C.), with a nitrogen flow of 10 cc/min, while the reactor oven was ramped up to 350 C. over 2 hours. When the system had stabilized at 350 C. the amount of beta-2-tet observed in the product gases was 71.7% (see Table 2).; Example 5; The catalyst, TOSOH HSZ-690 HOD (SAR 203) with the silica binder, was sized to a uniform particle size of 1-2 mm. A weight of 0.51 g of catalyst was charged into the reactor tube and glass wool (Pyrex) was used to secure it in place. The reactor temperature was initially set to 250 C. prior to flowing chlorine at a rate of 5 cc/min. The beta-picoline feed rate was set to 0.25 mg/min (N2 at 10 cc/min, chiller at 20 C.), while the reactor oven was slowly ramped up to 350 C. over 2 hours. When the system had stabilized at 350 C. the amount of beta-2-tet observed in the product gases was 66.9% (see Table 2).
With chlorine; at 400℃;Gas phase;Product distribution / selectivity;
Example A; This is the control run where the reactor contained glass wool (Pyrex) plugs and no catalyst. The reactor temperature was initially set to 350 C. prior to feeding chlorine at a rate of 5 cc/min. The beta-picoline feed rate was set to 0.25 mg/min (N2 at 10 cc/min, chiller at 20 C.) at the oven temperature of 350 C. When the system had stabilized the amount of beta-2-tet was only 8.7%, with the majority of the conversion going to beta-tri (65.4%). When the temperature was increased to 400 C. the amount of beta-2-tet increased to 46.1% with a reduction in beta-tri (21.5%). A fair amount of over chlorinated 2,6-dichloro-3-trichloromethylpyridine (beta-2,6-penta,12.2%) was also observed (see Table 2).
With chlorine;0.5% palladium on alumina; at 340℃;Gas phase;Product distribution / selectivity;
Example 1; The pelletized catalyst, 0.5% palladium catalyst on alumina (Harshaw Chemical Co.), was ground to a coarse powder and screened to obtain a uniform size of 1-2 mm in diameter. A weight of 0.25 g of catalyst was charged into the 0.25 reactor tube and glass wool (Pyrex) was used to secure it in place. Operating at an initial temperature of 250 C., a chlorine feed of 5 cc/min, a picoline feed rate of 0.13 mg/min (10 cc/min N2 with a chiller temperature of 10 C.), the reactor was ramped up to 340 C over about one hour. After the system stabilized at the reaction temperature of 340 C., the product gases contained 67.4% beta-2-tet (see Table 1 for conditions and Table 2 for results).
With P,P-dichlorophenylphosphine oxide; phosphorus pentachloride; at 160℃; for 5.0h;
A mixture of 2-hydroxypyridine-3-carboxylic acid (100.0 mmol), phenylphosphonic dichloride (33.0 mmol), and phosphorus pentachloride (330.0 mmol) was slowly heated to 160 C and the by-product (POCl3) was distilled. Then the mixture was stirred at the same temperature for 5 h. Thin-layer chromatographic (TLC) analysis showed the reaction had been finished. The POCl3 was evaporated in vacuum; the residue was poured into ice water, neutralized with saturated aqueous sodium carbonate solution, and extracted with acetic ether. The organic layer was washed with water, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure, and the obtained crude product was distilled or purified with silica-gel chromatography.
With triethylamine; trichlorophosphate; In dichloromethane; at 10 - 25℃;
To a 1 L four-necked flask was added 25 g of 3-trichloromethylpyridine oxynitride (0.13 mol).And 125g DCM (dichloromethane, 96mL),The temperature is then lowered to 10-15 C.POCl3 (40g, 0.26mol)Mix with DCM (25g) to form solution A,Mixing triethylamine (26 g, 0.26 mol) and DCM (50 g) into solution B,At a temperature of 10 C,Start to add 10% of the total amount of solution A,After 20 minutes,Then, the remaining 90% of the solution A and the entire solution B are simultaneously added dropwise.Ensure that both are dripped at the same time within 1-2h.The reaction was carried out at a temperature of 20-25 C for 3 h.Sampling, adding a small amount of water to quench the reaction, and then adding a sodium hydroxide or potassium hydroxide solution with a mass fraction of 10-20%. After centrifugation, the lower organic phase and the upper aqueous phase are separately analyzed and sent to liquid chromatography for analysis.The solution contained 28.5 g of the product 2-chloro-3-trichloromethylpyridine.The product purity is 98.0%.The molar yield was 93.1% (based on 3-chloromethylpyridine oxynitride).
With tetrachloromethane; at 200 - 350℃; for 0.00305556h;Molecular sieve; Inert atmosphere;
40 G ZSM - 5 molecular sieve (silicon-aluminum ratio 200, strip (1 - 2 mm)) by adding [...] 60 cm, diameter of 2.4 cm cylindrical quartz tube, the upper end of the catalyst filling 10 g of inert ceramic ball (diameter 4 mm), the quartz tube using the resistance wire heating. The constant pressure in the funnel 8 g 3 - methyl pyridine and 70 g CCl4[...] 200 C flask, 2 h the raw materials of the completion of the dropping, of the 3 - methyl pyridine with CCl4The steam is N2The carrier gas to the quartz tube, N2The flow rate control in 250 ml/min. Cl2In order to 300 ml/min flow rate individually to the quartz tube with the raw material of the steam in the catalyst bed on the reaction, the reaction temperature is 350 C, time is 11 s. The reaction mixture through the receiving flask condensation, GC normalized 3 - methyl pyridine totally transformed, 3 - dichloro pyridine and isomer 47%, 2 - chloro -5 - trichloromethyl pyridine 27%, 2 - chloro -3 - trichloromethyl pyridine 4.8%, 2, 3 - dichloro -5 - trichloromethyl pyridine 11%. The purity of the purification after rectification>99% of 2 - chloro -5 - trichloromethyl pyridine, the yield of 21%.
With tetrachloromethane; at 200 - 340℃; for 0.00388889h;Molecular sieve; Inert atmosphere;
45 G of a pure silicon TS - 1 molecular sieve (spherical particles (1 - 2 mm)) is added to the long 60 cm, diameter of 2.4 cm cylindrical quartz tube, the upper end of the catalyst filling 10 g of inert ceramic ball (diameter 4 mm). The constant pressure in the funnel 8 g 3 - methyl pyridine and 70 g CCl4[...] 200 C flask, 2 h the completion of the dropping, of the 3 - methyl pyridine with CCl4The steam is N2The carrier gas to the quartz tube, N2The flow rate control in 280 ml/min. Cl2In order to 300 ml/min flow rate individually to the quartz tube with the raw material of the steam in the catalyst bed on the reaction, the reaction temperature is 340 C, time is 14 s. The reaction mixture through the receiving flask condensation, GC normalized 3 - methyl pyridine totally transformed, 3 - dichloro pyridine and isomer 18%, 2 - chloro -5 - trichloromethyl pyridine 78%, 2 - chloro -3 - trichloromethyl pyridine 0.9%, other excessive chlorinated product. The purity of the purification after rectification>99% of 2 - chloro -5 - trichloromethyl pyridine, yield is 73%.
The <strong>[72648-12-5]2-chloro-3-trichloromethylpyridine</strong> is hydrolyzed to obtain a 2-chloronicotinic acid reaction product, and the reaction formula is as follows
As a further technical solution, the 3-methylpyridine and chlorine gas are reacted by heating 3-methylpyridine and chlorine gas at a molar ratio of 1:15 to above 200 C, and entering the shallow chlorination reactor in a gas phase. The reaction is carried out at 355 C to obtain a reaction mixed gas, and then the reaction mixed gas is introduced into the quenching tower. The excess chlorine gas and a small portion of the hydrogen chloride gas are separated by a separation column and returned to the shallow chlorination reactor, and the 2-column is obtained at the bottom of the quenching tower. -5-Dichloromethylpyridine, 2-chloro-5-trichloromethylpyridine, 2-chloro-3-trichloromethylpyridine liquid phase incubation, continuous distillation, separation, respectively for 2-chloro-5 - Dichloromethylpyridine, 2-chloro-5-trichloromethylpyridine, 2-chloro-3-trichloromethylpyridine for storage.
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