CN103570609B - A kind of preparation method of 2,3-dichloropyridine - Google Patents
A kind of preparation method of 2,3-dichloropyridine Download PDFInfo
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- CN103570609B CN103570609B CN201310514134.0A CN201310514134A CN103570609B CN 103570609 B CN103570609 B CN 103570609B CN 201310514134 A CN201310514134 A CN 201310514134A CN 103570609 B CN103570609 B CN 103570609B
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- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D213/61—Halogen atoms or nitro radicals
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Abstract
The invention discloses a kind of 2, the preparation method of 3-dichloropyridine, its innovative point is: be that raw material and sodium hypochlorite reaction prepare 3-aminopyridine with niacinamide, through dephlegmate, dichloromethane extraction reclaims 3-aminopyridine, by 3-aminopyridine in technical hydrochloric acid reextraction methylene dichloride, 3-aminopyridine yield >=93%; 3-aminopyridine hydrochloric acid soln and hydrogen peroxide react the hydrochloric acid soln obtained containing 2-chlorine-3-aminopyridine, yield >=85% of 2-chlorine-3-aminopyridine, then carry out diazotization and Sang Demaier reaction acquisition 2,3-dichloropyridine simultaneously.Preparation method's side reaction of the present invention is few, and intermediate product is without the need to refining, and product content is high, and yield is high, and technique is simple, easy to operate.
Description
Technical field
The present invention relates to a kind of preparation method of 2,3-dichloropyridine, specifically in particular to a kind of preparation method improving 2,3-dichloropyridines of product content and yield.
Background technology
2,3-dichloropyridine is a kind of chloro-pyridine of comparatively wide, the large usage quantity of purposes in 6 kinds of dichloropyridine isomer, and important fine-chemical intermediate, is widely used at medicine and pesticide field.It is the key intermediate of novel pesticide Rynaxypyr.The preparation method of current 2,3-dichloropyridines mainly adopts niacinamide and clorox to obtain 3-aminopyridine through hoffman degradation reaction, then obtains through oxi-chlorination, diazotization and Sang Demaier reaction, and its main side effect principle is as follows:
Main reaction:
Side reaction:
The method reaction principle is complicated, and it is more to cut side reaction, obtain comparatively that high product yield is more difficult.
Summary of the invention
The object of the invention is to for deficiency of the prior art, provide a kind of side reaction few, the preparation method of 2, the 3-dichloropyridines that product content is high.
For solving the problems of the technologies described above, the present invention adopts following technical scheme to realize: be that raw material and sodium hypochlorite reaction prepare 3-aminopyridine with niacinamide, through dephlegmate, dichloromethane extraction reclaims 3-aminopyridine, by 3-aminopyridine in technical hydrochloric acid reextraction methylene dichloride, 3-aminopyridine yield >=93%; 3-aminopyridine hydrochloric acid soln and hydrogen peroxide react the hydrochloric acid soln obtained containing 2-chlorine-3-aminopyridine, yield >=85% of 2-chlorine-3-aminopyridine, then carry out diazotization and Sang Demaier reaction acquisition 2,3-dichloropyridine simultaneously.
Select the mol ratio of niacinamide and clorox to be 1:1.1 in preparation process of the present invention, the temperature of niacinamide and sodium hypochlorite reaction is 0-5 DEG C.
Drip liquid caustic soda in described niacinamide and sodium hypochlorite reaction process, liquid caustic soda concentration is 50%.
Described dichloromethane extraction reclaims in 3-aminopyridine step, the ratio 18-20:1 of described methylene chloride volume and 3-aminopyridine quality.
In described technical hydrochloric acid reextraction methylene dichloride in 3-aminopyridine step, the mol ratio 11.5-12.5 of technical hydrochloric acid and 3-aminopyridine.
Described 3-aminopyridine hydrochloric acid soln and hydrogen peroxide react the hydrochloric acid soln obtained containing 2-chlorine-3-aminopyridine, hydrogen peroxide is dripped in 3-aminopyridine solution, drip 1.5-2 hour, 5-10 DEG C of insulation reaction, react after 1 hour, temperature of reaction is adjusted to 10-15 DEG C, continue reaction 1 hour, wherein, the concentration of hydrogen peroxide is the mol ratio of 25-30%, 3-aminopyridine and hydrogen peroxide is 1:1.2-1.3.
Diazotization and Sang Demaier react acquisition 2, the concrete steps of 3-dichloropyridine are the cuprous chloride adding 2-chlorine-3-aminopyridine 0.6 times of molar mass in 2-chlorine-3-aminopyridine reaction solution, temperature controls at 33-38 DEG C, agitation and dropping 2-chlorine-3-aminopyridine 1.25-1.35 times of molar mass sodium nitrite solution, churning time 2-3 hour, dropwise rear continuation at 33-38 DEG C of stirring reaction 20-40 minute, described use 40% sodium nitrite in aqueous solution.
The present invention adopts liquid chromatography external standard method, analyzes 3-aminopyridine, 2-chlorine-3-aminopyridine and 2,3-dichloropyridine content, calculates intermediates 3-aminopyridine, 2-chlorine-3-aminopyridine molar yield.
Obtained abovely contain 2,3-dichloropyridine chloroform extraction liquid, through Distillation recovery trichloromethane, refining methanol obtains purified product-2.3-dichloropyridine.
Beneficial effect of the present invention: compared with prior art, the present invention has the following advantages:
1, intermediate product does not need to refine, and walks product under can being directly used in preparation, reduces the generation for the treatment of process waste liquid, save energy, reduces production cost;
2, diazotization and Sang Demaier reaction are carried out simultaneously, shorten preparation process;
3, be that raw material can one pot process 2,3-dichloropyridine by 3-aminopyridine;
4, product content >=98.0%(liquid chromatograph, external standard method);
5, molar product yield >=60%(is in niacinamide).
Embodiment
Below in conjunction with specific embodiment, technical scheme of the present invention is elaborated.
Embodiment 1
The preparation of 3-aminopyridine: in the 1000 milliliters of four mouthfuls of round-bottomed flasks having stirring, thermometer, add 150 ml waters, stir lower input niacinamide 36.6 grams (0.3mol), be cooled to 0-5 DEG C until completely dissolved, then within 30-60 minute period and 0-5 DEG C, drip 9.05% chlorine bleach liquor 272 grams (0.33mol), after dropwising, stir 30min.In same temperature, dripping concentration is 50% liquid caustic soda 48 grams (0.6mol), stirring reaction 30 minutes.
Stirring is had, in 1000 milliliters of four mouthfuls of round-bottomed flasks that temperature takes into account prolong at another, add 240 ml waters, heat between 90-100 DEG C, in this temperature range and 30-45 minute period, drip the above reaction solution preserved at 0-5 DEG C, dropwise and continue insulation reaction 2 hours, after completion of the reaction, reaction solution weight 747 grams, analyze 3-aminopyridine content (liquid chromatograph, external standard method), Nicotinic Acid Content (peak area: 0.72%), 3-aminopyridine molar yield: 95.2%.
With 30% liquid caustic soda, above reaction solution is neutralized neutrality, vacuum distillation is except anhydrating, in room temperature and under stirring, dissolve 3-aminopyridine with 300 milliliters of methylene dichloride, filtration, with 200 milliliters of washed with dichloromethane salt, obtain the dichloromethane solution containing 3-aminopyridine, with the dichloromethane solution of 360 grams of technical hydrochloric acid extraction 3-aminopyridine, obtain the hydrochloric acid soln of 3-aminopyridine, with liquid chromatograph, external standard method is analyzed, 3-aminopyridine molar yield 94.1%.
The preparation of 2-chlorine-3-aminopyridine: having stirring, in 1000 milliliters of four mouthfuls of round-bottomed flasks of thermometer, add above 3-aminopyridine solution, 45.4 grams, the hydrogen peroxide (0.36mol) of 5-10 DEG C of dropping 27%, time for adding 1.5-2 hour, 5-10 DEG C of insulation reaction, react after 1 hour, temperature of reaction is adjusted to 10-15 DEG C, continue reaction 1 hour, start sampling analysis, when reacting to the highest and impurity peak area≤15% of product peak area, reaction terminates, add 10 grams of sodium bisulfites not aobvious blue to starch potassium iodide paper, with liquid chromatograph, external standard method is analyzed, 2-chlorine-3-aminopyridine molar yield 85.2%(is in 3-aminopyridine).
2, the preparation of 3-dichloropyridine: to containing in 2-chlorine-3-aminopyridine reaction solution, add 15 grams of cuprous chlorides, temperature is controlled at 33-38 DEG C, in stirring and 2-3 hour period, drip the sodium nitrite solution prepared by 23 grams of Sodium Nitrites (0.33 mole) and 34.5 ml waters, aobvious blue to starch potassium iodide paper, and through repeatedly detecting, starch potassium iodide paper keeps blue, otherwise also needs to add Sodium Nitrite.Dropwise rear continuation 33-38 DEG C of stirring reaction 30 minutes, reaction terminates.Obtain the reaction solution containing 2,3-dichloropyridine.Under agitation, sampling, with liquid chromatograph, external standard method analysis, 2,3-dichloropyridine molar yield 86.6%.
The extraction and recovery of 2,3-dichloropyridine: in above-mentioned reaction solution, add 150 ml waters, between 40-45 DEG C, with 50 milliliters × 4 chloroform extractions, reclaims the chloroform extraction liquid merged containing 2,3-dichloropyridine, with the liquid caustic soda of 30%, pH value is adjusted to 7-8.
Distillation recovery trichloromethane: neutralization distill to the chloroform extraction liquid of PH7-8, recovery trichloromethane, distillation will at the end of, in still kettle, add water, continue to be distilled to temperature about 100 DEG C, through wet distillation recovery product.Cooling, filtered and recycled 2,3-dichloropyridine.
Refining: to refine with anhydrous methanol, the mass ratio of methyl alcohol and crude product is 0.8:1, through heating for dissolving, be then cooled to 20-25 DEG C of crystallization, filtered and recycled, drying obtain purified product 28.5 grams, content: 98.6%(liquid chromatograph, external standard method), molar yield 64.2%(is in niacinamide).
The preparation of embodiment 2:3-aminopyridine
Method 1: having stirring, in 1000 milliliters of four mouthfuls of round-bottomed flasks that temperature takes into account prolong, add 300 ml waters, stir the lower niacinamide 73.3 grams (0.6mol) dropping into accurate measurement, be cooled to 0-5 DEG C until completely dissolved, be added dropwise to 30% liquid caustic soda 26.7 grams (0.2mol).Then the temperature controlling material, within the scope of 0-5 DEG C, drips 9.05% chlorine bleach liquor 545 grams (0.66mol), after dropwising, stirs 30min.In same temperature index, dripping concentration is 30% liquid caustic soda 213 grams (1.6mol), dropwises rear control material in 0-8 DEG C.Stir intensification in 30 minutes, be warming up to 70-80 DEG C, insulation reaction 2 hours, after completion of the reaction, claim reaction solution weight (1184 grams), with liquid chromatograph, external standard method analyzes 3-aminopyridine content, molar yield: 86%.
Method 2: in the 1000 milliliters of four mouthfuls of round-bottomed flasks having stirring, thermometer, add 150 ml waters, stir lower input niacinamide 36.6 grams (0.3mol), be cooled to 0-5 DEG C until completely dissolved, then add 30% liquid caustic soda 8 grams (0.1mol), within 30-60 minute period and 0-5 DEG C, drip 9.05% chlorine bleach liquor 272 grams (0.33mol), after dropwising, stir 30min.In same temperature, dripping concentration is 30% liquid caustic soda 0.5mol, continues 0-5 DEG C of stirring reaction 120 minutes.Reaction terminates.
Stirring is had, in 1000 milliliters of four mouthfuls of round-bottomed flasks that temperature takes into account prolong at another, reaction solution 395 grams prepared by Adding Way 1, heat between 90-100 DEG C, in this temperature range and 30-45 minute period, drip the above reaction solution preserved at 0-5 DEG C, dropwise and continue 90-100 DEG C of insulation reaction 2 hours, react complete, claim reaction solution weight, with liquid chromatograph, external standard method analyzes 3-aminopyridine content, molar yield: 96.3%.
Embodiment 3
The preparation of 2-chlorine-3-aminopyridine: having stirring, in 1000 milliliters of four mouthfuls of round-bottomed flasks of thermometer, add 360 grams of technical hydrochloric acid (content: 30.5%, 3mol), 0.3mol(28.2 gram) 3-aminopyridine, stirring and dissolving, 45.4 grams, the hydrogen peroxide (0.36mol) of 10-15 DEG C of dropping 27%, time for adding 1.5-2 hour, 10-15 DEG C of insulation reaction, react after 3.5 hours, reaction terminates, add 10 grams of sodium bisulfites not aobvious blue to starch potassium iodide paper, with liquid chromatograph, external standard method is analyzed, 2-chlorine-3-aminopyridine molar yield 86.5%(is in 3-aminopyridine).
Following preparation method with embodiment 1,2,3-dichloropyridine content in the present embodiment: 98.8%, molar yield: 69.5%.
Above-described embodiment is only in order to illustrate technical scheme of the present invention; but not design of the present invention and protection domain are limited; those of ordinary skill of the present invention is modified to technical scheme of the present invention or equivalent replacement; and not departing from aim and the scope of technical scheme, it all should be encompassed in right of the present invention.
Claims (7)
1. one kind 2, the preparation method of 3-dichloropyridine, it is characterized in that: be that raw material and sodium hypochlorite reaction prepare 3-aminopyridine with niacinamide, through dephlegmate, dichloromethane extraction reclaims 3-aminopyridine, by 3-aminopyridine in technical hydrochloric acid reextraction methylene dichloride, 3-aminopyridine yield >=93%; 3-aminopyridine hydrochloric acid soln and hydrogen peroxide react the hydrochloric acid soln obtained containing 2-chlorine-3-aminopyridine, yield >=85% of 2-chlorine-3-aminopyridine, then carry out diazotization and Sang Demaier reaction acquisition 2,3-dichloropyridine simultaneously;
Described dichloromethane extraction reclaims in 3-aminopyridine step, the ratio 18-20:1 of methylene chloride volume and 3-aminopyridine quality;
In described technical hydrochloric acid reextraction methylene dichloride in 3-aminopyridine step, the mol ratio 11.5-12.5:1 of technical hydrochloric acid and 3-aminopyridine;
Described 3-aminopyridine hydrochloric acid soln and hydrogen peroxide react the hydrochloric acid soln step obtained containing 2-chlorine-3-aminopyridine: in 3-aminopyridine solution, drip hydrogen peroxide, drip 1.5-2 hour, 5-10 DEG C of insulation reaction, react after 1 hour, temperature of reaction is adjusted to 10-15 DEG C, continue reaction 1 hour, the concentration of described hydrogen peroxide is the mol ratio of 25-30%, 3-aminopyridine and hydrogen peroxide is 1:1.2-1.3;
Described diazotization and Sang Demaier react acquisition 2, the concrete steps of 3-dichloropyridine are: the cuprous chloride adding 2-chlorine-3-aminopyridine 0.6 times of molar mass in 2-chlorine-3-aminopyridine reaction solution, temperature controls at 33-38 DEG C, agitation and dropping 2-chlorine-3-aminopyridine 1.25-1.35 times of molar mass sodium nitrite solution, churning time 2-3 hour, dropwises rear continuation at 33-38 DEG C of stirring reaction 20-40 minute.
2. the preparation method of a kind of 2,3-dichloropyridines according to claim 1, is characterized in that: the mol ratio of described niacinamide and clorox is 1:1.1.
3. the preparation method of a kind of 2,3-dichloropyridines according to claim 1, is characterized in that: the temperature of described niacinamide and sodium hypochlorite reaction is 0-5 DEG C.
4. the preparation method of a kind of 2,3-dichloropyridines according to claim 1, it is characterized in that: drip liquid caustic soda in described niacinamide and sodium hypochlorite reaction process, liquid caustic soda concentration is 30-50%.
5. the preparation method of a kind of 2,3-dichloropyridines according to claim 1, is characterized in that: use 40% sodium nitrite in aqueous solution.
6. the preparation method of a kind of 2,3-dichloropyridines according to claim 1, is characterized in that: adopt liquid phase chromatography, and external standard method analyzes the molar yield of 3-aminopyridine, 2-chlorine-3-aminopyridine and 2,3-dichloropyridine molar yield.
7. the preparation method of a kind of 2,3-dichloropyridines according to claim 1, is characterized in that: what obtain contains 2,3-dichloropyridine chloroform extraction, Distillation recovery trichloromethane, refines and obtains purified product.
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| CN106146393A (en) * | 2015-04-14 | 2016-11-23 | 利尔化学股份有限公司 | Prepare 3,4,6-trichloropyridine-2-formic acid and the method for corresponding esters thereof |
| CN104926715A (en) * | 2015-06-03 | 2015-09-23 | 安徽绩溪县徽煌化工有限公司 | Method for preparing 2,3-dichloropyridine |
| CN106748980A (en) * | 2015-11-22 | 2017-05-31 | 宁夏际华环境安全科技有限公司 | A kind of dichloropyridine production technology |
| CN105399663B (en) * | 2015-12-23 | 2018-09-14 | 山东天信化工有限公司 | A method of preparing 2,3- dichloropyridines |
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| CN106588756A (en) * | 2016-11-11 | 2017-04-26 | 山东天信化工有限公司 | Method for preparing 2,3-dichloropyridine |
| CN108484492A (en) * | 2018-05-23 | 2018-09-04 | 安徽国星生物化学有限公司 | Niacinamide synthesizes the technical study of 2,3,6- trichloropyridines |
| CN110885311B (en) * | 2019-12-11 | 2023-05-02 | 江西天戌药业有限公司 | Preparation method of 2-chloro-3-aminopyridine |
| CN111170937A (en) * | 2020-01-08 | 2020-05-19 | 山东泓达生物科技有限公司 | Preparation method of 3-aminopyridine |
| CN113149896A (en) * | 2021-03-09 | 2021-07-23 | 利尔化学股份有限公司 | Preparation method of 3-aminopyridine |
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