2-Chloronicotinic acid has many uses, including:
1. Used as pharmaceutical intermediate: 2-Chloronicotinic acid is an important intermediate for the preparation of a variety of drugs, such as drugs for the treatment of heart disease and cancer.
2. Used as a precursor of pesticides and herbicides: 2-Chloronicotinic acid can be used as a precursor for the preparation of pesticides and herbicides.
3. Used as organic synthesis reagent: 2-Chloronicotinic acid can be used as organic synthesis reagent, for example, to prepare pyridine compounds.
4. Used to prepare organic photoelectric materials: 2-Chloronicotinic acid can be used to prepare various organic photoelectric materials, such as light-emitting diodes (LEDS), organic field-effect transistors (OFETS), etc.
In short, 2-Chloronicotinic acid has a broad application prospect in the fields of pharmaceuticals, pesticides, organic synthesis, photoelectric materials, etc.
2-Chloronicotinic acid can be synthesized by the following routes:
1. Chlorination of 2-chloropyridine: 2-chloropyridine can be obtained by reacting 2-chloropyridine with hydrogen chloride.
2. Sodium hydroxide hydrolysis: 2-chloropyridine is reacted with sodium hydroxide, and then hydrolyzed with water to obtain 2-chloropyridine sodium.
3. Acidification: 2-chloropyridyl acid can be obtained by reacting sodium 2-chloropyridyl acid with hydrochloric acid.
4. Oxidation: 2-chloropyridine-5-one can be obtained by reacting 2-chloropyridinic acid with benzoyl peroxide.
5. Reduction: 2-chloropyridine-5-acetic acid can be obtained by reacting 2-chloropyridine-5-ketone with sodium bisulfite and hydrogen.
6. Acidification: 2-chloropyridine-5-acetic acid hydrochloride can be obtained by reacting 2-chloropyridine-5-acetic acid with hydrochloric acid.
7. Deacetic acid: 2-chloropyridine-5-acetic acid hydrochloride is reacted with sodium hydroxide to obtain 2-chloropyridine-5-carboxylic acid.
Therefore, the synthesis route of 2-Chloronicotinic acid is as follows:
2-chloropyridine → 2-chloropyridyl acid sodium → 2-chloropyridyl acid → 2-chloropyridyl-5-one → 2-chloropyridyl-5-acetic acid → 2-chloropyridyl-5-acetic acid hydrochloride → 2-Chloronicotinic acid
The following is the laboratory synthesis route of 2-Chloronicotinic acid:
1. Chlorination of 2-chloropyridine: in dry cyclohexane, 2-chloropyridine is dripped into concentrated hydrochloric acid, and ferrous chloride is added as catalyst. After reaction, filter and wash the solid with cyclohexane to obtain 2-chloropyridine.
2. Sodium hydroxide hydrolysis: add 2-chloropyridine and sodium hydroxide into water, stir and heat to 80 ° C until complete hydrolysis. Then the reaction mixture is cooled to room temperature, filtered and washed with water to obtain sodium 2-chloropyridylate.
3. Acidification: dissolve sodium 2-chloropyridylate in water, add hydrochloric acid to adjust pH to acidity, and then extract with methyl chloride. Acidize the organic phase with concentrated hydrochloric acid, filter the solid and wash with water to obtain 2-chloropyridyl acid.
4. Oxidation: dissolve 2-chloropyridyl acid in ethanol, add benzoyl peroxide, and stir for reaction at room temperature for 2 hours. After reaction, the solid was washed with water and washed with ethanol to obtain 2-chloropyridine-5-ketone.
5. Reduction: add 2-chloropyridine-5-ketone, sodium bisulfite and water into the reaction bottle, and then inject hydrogen to conduct reduction reaction. After reaction, the solid was washed with ethanol and washed with water to obtain 2-chloropyridine-5-acetic acid.
6. Acidification: dissolve 2-chloropyridine-5-acetic acid in ethanol and add hydrochloric acid for acidification. The solid was washed with ethanol and washed with water to obtain 2-chloropyridine-5-acetic acid hydrochloride.
7. Deacetic acid: add 2-chloropyridine-5-acetic acid hydrochloride and sodium hydroxide into water, and heat and stir. After reaction, wash the solid with water and ethanol to obtain 2-Chloronicotinic acid.
The following is the laboratory synthesis route of 2-Chloronicotinic acid:
1. Add 10.0 g of 2-chloropyridine and 20 mL of concentrated hydrochloric acid (37%) to a 500 mL round-bottomed flask with an ice water bath, and mix them completely.
2. Add 40 mL of separated water at room temperature, continue stirring for 10 minutes, and then centrifuge the mixture for 15 minutes to separate the water layer and collect the organic layer into a clean round-bottomed flask.
3. Add the collected organic layer into a clean 250 mL round bottom flask, add 50 mL of 10% sodium hydroxide solution, and stir for 15 minutes.
4. Add 80 mL of separated water at room temperature and stir for another 5 minutes. Then centrifuge the mixture for 15 minutes, separate the water layer and collect the organic layer into a clean round bottom flask.
5. Evaporate the collected organic layer to the residue through the rotary evaporator and transfer it to a clean 250 mL round bottom flask.
6. Add 25 mL of absolute ethanol and 20 mL of concentrated hydrochloric acid (37%) to it, and stir until it is completely mixed.
7. Add 25 mL of benzoyl ethyl peroxide at room temperature, stir for 5 minutes, and then heat at 100 ℃ for 6 hours.
8. Add 10 mL of sodium bisulfite solution (10%) at room temperature, stir for 30 minutes, then add 10 mL of concentrated hydrochloric acid (37%), and adjust the pH to acidic.
9. Centrifuge the mixture for 15 minutes, separate the water layer and collect the organic layer into a clean round bottom flask.
10. Add 20 mL of anhydrous ethanol and 10 mL of concentrated ammonia at room temperature, and stir until completely mixed.
11. Centrifuge the mixture for 15 minutes, separate the water layer and collect the organic layer into a clean round bottom flask.
12. Evaporate the collected organic layer to the residue through the rotary evaporator, and add 20 mL of water and 5 mL of concentrated hydrochloric acid (37%) for acidification.
13. Add 40 mL of separated water at room temperature, stir for 5 minutes, and then centrifuge the mixture for 15 minutes to separate the water layer and collect the organic layer into a clean bottle for ethanol separation to obtain 2-Chloronicotinic acid.