2942-59-8

Basic information

• Product Name: 2-Chloronicotinic acid
• Synonyms: TIMTEC-BB SBB004002;2-chloro-3-pyridinecarboxylicaci;RARECHEM AL BO 0287;AKOS BBS-00004231;2-CHLORO-3-PYRIDINECARBOXYLIC ACID;2-CHLOROPYRIDINE-3-CARBOXYLIC ACID;2-CHLOROPYRIDIN-3-CARBOXYLIC ACID;2CLNA
• CAS NO: 2942-59-8
• Molecular Formula: C₆H₄ClNO₂
• Molecular Weight: 157.55
• EINECS: 220-937-0
• Product Categories: blocks;Carboxes;Pyridines;Pyridine;Acids and Derivatives;Heterocycles;Pyridines, Pyrimidines, Purines and Pteredines;Carboxylic Acids;Organic acids;Diflufenican;Chloropyridines;Halopyridines;Carboxylic Acids;pyridine series;ACID;carboxylic acid| alkyl chloride;Pharmaceutical intermediates;Imidazoles
• Mol File: 2942-59-8.mol
• Article Data: 28

Chemical Properties

• Melting Point: 176-178 °C (dec.)(lit.)
• Boiling Point: 316.8 °C at 760 mmHg
• Flash Point: 145.4 °C
• Appearance: White to cream/Powder
• Density: 1.47 g/cm³
• Vapor Pressure: 0.000168mmHg at 25°C
• Storage Temp.: Store below +30°C.
• Solubility: DMSO, Ethyl Acetate (Slightly)
• PKA: 2.07±0.25(Predicted)
• BRN: 119023
• CAS DataBase Reference: 2-Chloronicotinic acid(CAS DataBase Reference)
• NIST Chemistry Reference: 2-Chloronicotinic acid(2942-59-8)
• EPA Substance Registry System: 2-Chloronicotinic acid(2942-59-8)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 22-24/25-37/39-26-36
• WGK Germany: 3
• TSCA: T
• HazardClass: IRRITANT
• Hazardous Substances Data: 2942-59-8(Hazardous Substances Data)

Usage

Uses

Used in Pharmaceutical Industry:
2-Chloronicotinic acid is used as a pharmaceutical intermediate for the synthesis of anti-inflammatory and analgesic drugs like pralofen. It plays a crucial role in the production of mefenamic acid and niflumic acid, which are widely used for their therapeutic properties.
Used in Agrochemical Industry:
In the agrochemical sector, 2-Chloronicotinic acid is utilized as an intermediate in the development of herbicides such as nicosulfuron and diflufenican. These herbicides are essential for effective weed control in agricultural practices.
Used in Chemical Synthesis:
2-Chloronicotinic acid is also employed in the preparation of 4-thiazolidinone derivatives and Schiff bases, which exhibit antimicrobial activity. This application highlights its significance in the development of new compounds with potential applications in various industries, including pharmaceuticals and materials science.

Preparation

Chloronicotinic acid was synthesized from nicotinic acid by oxidation by H2O2 and then chlorinationby POCl3 and PCl5 in a yield of 87.5%.Synthesis of 2-chloronicotinic acid: Pour chlorine gas into the mixed solution of phosphorus oxychloride and phosphorus trichloride, control the temperature at about 60°C, until the remaining chlorine gas escapes, cool and add nicotinic acid N-oxide in batches, and heat the mixed solution. The reaction was carried out at 100-105°C for 1-1.5 h, and the reaction mixture was stirred for 30 min after the reaction mixture was transparent, and phosphorus oxychloride was removed under reduced pressure. The obtained residue was cooled to room temperature, and water was added to obtain the finished product of 2-chloronicotinic acid.

InChI:InChI=1/C6H4ClNO2/c7-5-4(6(9)10)2-1-3-8-5/h1-3H,(H,9,10)/p-1

Synthetic route

2 chloro-3-methylpyridine (18368-76-8) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With ozone; acetic acid at 20℃; for 5h; Reagent/catalyst; Temperature;	98%
With N-hydroxyphthalimide; oxygen; cobalt(III) acetylacetonate In acetonitrile at 80℃; under 7500.75 Torr; for 18h; Reagent/catalyst; Temperature; Autoclave;	94.1%
With permanganate(VII) ion

2-chloro-3-ethylpyridine (96440-05-0) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With sodium acetate; ozone; acetic acid at 20℃; for 5h; Temperature; Reagent/catalyst;	98%
With potassium permanganate; water

2-chloro-3-isopropylpyridine → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With iron(II) acetate; ozone; acetic acid at 100℃; Reagent/catalyst; Temperature;	98%

2-chloro-3-(dichloromethyl)-pyridine → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With 10% Ru/C; oxygen; sodium carbonate In tetrahydrofuran at 140℃; under 22502.3 - 30003 Torr; for 4h; Catalytic behavior; Temperature; Solvent; Pressure; Autoclave; Green chemistry;	95.4%

ethyl 2-chloronicotinate (1452-94-4) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With sodium hydroxide at 80℃; for 2h; Temperature;	95.2%
With sodium hydroxide In methanol; water at 75℃;

2-chloro-3-(chloromethyl)pyridine (89581-84-0) + acetic acid (64-19-7) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With sodium nitrite In dimethyl sulfoxide at 20℃; for 8h; Temperature; Solvent;	95.1%

2-Chloronicotinoyl chloride (49609-84-9) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With water at 0 - 5℃; for 0.5h; pH=1.5; Alkaline conditions; Green chemistry;	92%
In water

Pyridine-2,3-dicarboxylic acid (89-00-9) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With potassium permanganate; chlorine In water at 85 - 90℃; Reagent/catalyst; Solvent;	91%

2-chloro-3-(trichloromethyl)-pyridine (72648-12-5) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With sulfuric acid; lithium acetate; water; silver; fluorosulphonic acid; acetic acid In methanol at 55 - 60℃; Electrolysis;	91%
With water

nicotinic acid (59-67-6) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
Stage #1: nicotinic acid With dihydrogen peroxide; acetic acid In toluene Reflux; Stage #2: With phosphorus pentachloride; trichlorophosphate In toluene Reflux;	90%
Multi-step reaction with 3 steps 1: molybdic acid; dihydrogen peroxide / water / 3 h / 92 - 95 °C / Green chemistry 2: trichlorophosphate; triethylamine / 6 h / 10 - 100 °C / Green chemistry 3: water / 0.5 h / 0 - 5 °C / pH 1.5 / Alkaline conditions; Green chemistry View Scheme

2-chloro-3-pyridinecarbonitrile (6602-54-6) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With water; sodium hydroxide for 3h; Reflux;	90%
With sulfuric acid at 100℃; for 10h;	88%
With water; sodium chloride; sodium hydroxide at 90℃; Reagent/catalyst; Temperature;

2-chloro-3-vinylpyridine (1033125-18-6) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With zinc diacetate; ozone In ethanol at 100℃;	87%

2-chloro-3-tert-butylpyridine → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With zinc diacetate; ozone In acetonitrile at 100℃;	85%

3-cyanopyridine N-oxide (14906-64-0) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With bis(trichloromethyl) carbonate In 5,5-dimethyl-1,3-cyclohexadiene; N,N-dimethyl-formamide for 0.0833333h; Solvent; Reagent/catalyst; Time; Reflux; Large scale; Green chemistry;	68.6%

Nicotinic acid N-oxide (2398-81-4) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With triethylamine; trichlorophosphate at 100℃; for 4h;	65%

carbon monoxide (201230-82-2) + 2-chloro-3-iodopyridine (78607-36-0) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With water; palladium diacetate; triethylamine; triphenylphosphine In 1,4-dioxane at 110℃; under 11251.1 Torr; for 2h; Flow reactor;	57%

(2-chloropyrid-3-yl)methanol (42330-59-6) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With 3,5-Lutidine; 4-acetylamino-2,2,6,6-tetramethylpiperidine-N-oxyl; sodium persulfate; tris(2,2'‐bipyridine)ruthenium(II) hexafluorophosphate In water; acetonitrile at 20℃; for 48h; Sealed tube; Irradiation;	24%

2-hydroxy-3-carboxypyridine (609-71-2) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With phosphorus pentachloride; trichlorophosphate
With sodium hydroxide; trichlorophosphate In toluene

2-chloro-3-pyridinecarbonitrile (6602-54-6) + glycine (56-40-6) → 2-chloronicotinic acid (2942-59-8) + N-(3-carboxamido-2-pyridyl)glycine (74149-43-2)

Conditions	Yield
With sodium carbonate In water for 12h; Heating;	A n/a B 1.4 g

Nicotinic acid N-oxide (2398-81-4) → 6-Chloro-3-pyridinecarboxylic acid (5326-23-8) + 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With phosphorus pentachloride; trichlorophosphate

Nicotinic acid N-oxide (2398-81-4) → 2-chloronicotinic acid (2942-59-8) + 1-(5-Carboxy-2-pyridyl)-2-pyridon-3-carbonsaeure (117638-64-9)

Conditions	Yield
With trichlorophosphate In N,N-dimethyl-formamide Yield given;

α-chloro-nicotine → 2-chloronicotinic acid (2942-59-8)

2-oxy-nicotinic acid → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With phosphorus pentachloride; trichlorophosphate at 140℃; Zersetzen des Reaktionsprodukts mit Wasser;

nicotinic acid-1-oxide → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With phosphorus pentachloride; trichlorophosphate

(S)-2'-chloro-1,2,3,4,5,6-hexahydro-<2,3'>bipyridyl → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With potassium permanganate

2-<2-oxo-1,2-dihydro-pyridine-3-carbonylimino>-2H-<1,2'>bipyridyl-3'-carboxylic acid → 5H-dipyrido<1,2-a:3',2'>pyrimidin-5-one (106531-39-9) + 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
With phosphorus pentachloride; trichlorophosphate

Nicotinic acid N-oxide (2398-81-4) + phosphorus pentachloride (10026-13-8, 874483-75-7) + trichlorophosphate (10025-87-3, 12599-09-6, 63736-95-8) → 2-chloronicotinic acid (2942-59-8) + 4-chloronicotinic acid (10177-29-4)

nicotinic acid-1-oxide → 2-chloronicotinic acid (2942-59-8) + 4-chloronicotinic acid (10177-29-4)

Conditions	Yield
With phosphorus pentachloride; trichlorophosphate

ethyl 2-chloro-2-cyano-5-oxopentanoate (152361-99-4) → 2-chloronicotinic acid (2942-59-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: 65 percent / PCl3, HCl(g) / dimethylformamide; toluene / 1.) 60 deg C, 30 min; 2.) 90 deg C, 1.5 h 2: NaOH / methanol; H2O / 75 °C View Scheme

diazomethane (186581-53-3, 908094-01-9) + 2-chloronicotinic acid (2942-59-8) → methyl 2-chloropyridine-3-carboxylate (40134-18-7)

Conditions	Yield
In methanol at -15℃; for 4h;	100%
In methanol; diethyl ether; ethanol	84%
	78%
With methanol; diethyl ether

2-chloronicotinic acid (2942-59-8) → 2-Chloronicotinoyl chloride (49609-84-9)

Conditions	Yield
With thionyl chloride for 3h; Heating;	100%
With oxalyl dichloride; N,N-dimethyl-formamide In dichloromethane at 25℃; for 3h; Inert atmosphere;	100%
With thionyl chloride for 3h; Heating;	99%

2-chloronicotinic acid (2942-59-8) + 4-amino-1-methyl-3-propyl-1H-pyrazole-5-carboxamide (139756-02-8) → N-(5-carbamoyl-1-methyl-3-propyl-1H-pyrazol-4-yl)-2-chloronicotinamide (1370409-73-6)

Conditions	Yield
With triethylamine; bromo-tris(1-pyrrolidinyl)phosphonium hexafluorophosphate In 1,2-dichloro-ethane at 120℃; for 0.333333h; Microwave irradiation;	100%

2-chloronicotinic acid (2942-59-8) + methyl 3-amino-5-ethoxybenzoate (706792-04-3) → methyl 3-(2-chloronicotineamido)-5-ethoxybenzoate

Conditions	Yield
With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 20℃; for 2h; Large scale;	100%

2-chloronicotinic acid (2942-59-8) + ethylamine (75-04-7) → 2-(ethylamino)-3-pyridine carboxylic acid (669087-25-6)

Conditions	Yield
at 120℃; for 4h;	99.7%
at 120℃; for 4h; Sealed vessel;	99.7%

2-chloronicotinic acid (2942-59-8) → C12H6Cl2N2O3 (75910-09-7)

Conditions	Yield
With 1-ethyl-piperidine; N,N-bis[2-oxo-3-oxazolidinyl]phosphorodiamidic chloride In tetrahydrofuran at 20℃; for 0.666667h;	99%

2-chloronicotinic acid (2942-59-8) → 3-bromo-fluorophenylmercaptan

Conditions	Yield
In N,N-dimethyl-formamide; trichlorophosphate	99%

2-chloronicotinic acid (2942-59-8) + diazomethyl-trimethyl-silane (18107-18-1) → methyl 2-chloropyridine-3-carboxylate (40134-18-7)

Conditions	Yield
In tetrahydrofuran; methanol; hexane at 20℃; for 1.5h;	99%
In methanol; hexanes; toluene at 20℃;	85.42%

2-chloronicotinic acid (2942-59-8) + 1-(4,4'-dichloro-benzhydryl)-piperazine (27469-61-0) → (4-(bis(4-chlorophenyl)methyl)piperazin-1-yl)(2-chloropyridin-3-yl)methanone

Conditions	Yield
With O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate; N-ethyl-N,N-diisopropylamine In dichloromethane at 20℃;	99%

2-chloronicotinic acid (2942-59-8) + methylamine (74-89-5) → 2-(methylamino)pyridine-3-carboxylic acid (32399-13-6)

Conditions	Yield
In water at 140℃; for 1.5h; Reactivity; Concentration; Temperature; Time; Microwave irradiation; Biotage Initiator;	98%
With sodium hydroxide In methanol at 90℃; for 48h; Temperature; Solvent; Autoclave;	93.8%
In water at 120℃; for 15h; sealed tube;	56%
With pyridine; toluene-4-sulfonic acid In water Heating;
In ethanol at 80℃; for 80h; Autoclave;

2-chloronicotinic acid (2942-59-8) + N-methyl-1H-benzo[d]imidazol-2-amine (17228-38-5) → 5,6-dihydro-6-methyl-5-oxopyrido<3',2':5,6>pyrimido<1,2-a>benzimidazole

Conditions	Yield
With Ullmann copper; potassium carbonate; potassium iodide In N,N-dimethyl-formamide at 170℃; for 5h;	98%

2-chloronicotinic acid (2942-59-8) + ethanol (64-17-5) → ethyl 2-chloronicotinate (1452-94-4)

Conditions	Yield
Stage #1: 2-chloronicotinic acid With thionyl chloride Stage #2: ethanol	98%
With dmap; dicyclohexyl-carbodiimide In N,N-dimethyl-formamide for 4h;	95%
With sulfuric acid for 2h; Reflux;	79%

2-chloronicotinic acid (2942-59-8) → methyl 2-chloropyridine-3-carboxylate (40134-18-7)

Conditions	Yield
With thionyl chloride; triethylamine In methanol; toluene	98%
Multi-step reaction with 2 steps 1: SOCl2 / 2.5 h / Heating 2: Et3N / Ambient temperature View Scheme
Multi-step reaction with 2 steps 1: thionyl chloride / 2 h / Heating 2: 1 h / Heating View Scheme
Multi-step reaction with 2 steps 1: SOCl2 / benzene / 3 h / Heating 2: 0.33 h / Heating View Scheme
With thionyl chloride In methanol

2-chloronicotinic acid (2942-59-8) + ethyl iodide (75-03-6) → ethyl 2-chloronicotinate (1452-94-4)

Conditions	Yield
With potassium carbonate In N-methyl-acetamide; water	98%
With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 72h;

2-chloronicotinic acid (2942-59-8) + 4-Ethoxyaniline (156-43-4) → 2-[(4-ethoxyphenyl)amino]pyridine-3-carboxylic acid (4394-10-9)

Conditions	Yield
With potassium carbonate In water at 150℃; for 1.5h; Green chemistry;	98%
With potassium carbonate In water at 150℃; for 1h; Microwave irradiation;	86%

2-chloronicotinic acid (2942-59-8) + 1-t-Butoxycarbonylpiperazine (57260-71-6) → 1-(2-chloronicotinoyl)piperazine hydrochloride

Conditions	Yield
Stage #1: 2-chloronicotinic acid With thionyl chloride In dichloromethane at 0 - 50℃; for 4h; Reflux; Stage #2: 1-t-Butoxycarbonylpiperazine With triethylamine In dichloromethane for 1h; Stage #3: With hydrogenchloride In ethanol for 1h; Reflux;	98%

2-chloronicotinic acid (2942-59-8) + 2-methyl-3-trifluoromethylaniline (54396-44-0) → flunixin (38677-85-9)

Conditions	Yield
With perfluorosulfonic acid resin In water at 65 - 70℃; for 2.5h; Temperature; Industrial scale;	97.1%
With potassium hydroxide; toluene-4-sulfonic acid In water	83%
With pyridine; toluene-4-sulfonic acid In water Reflux;	73%
With toluene-4-sulfonic acid; copper(II) oxide; sodium hydroxide In 1,2-dimethoxyethane; water at 45℃; for 0.6h; Reagent/catalyst; Temperature;

2-chloronicotinic acid (2942-59-8) + thiophenol (108-98-5) → 2-(phenylthio)nicotinic acid (35620-72-5)

Conditions	Yield
With potassium carbonate In water at 180℃; for 2h;	97%
at 190℃;

2-chloronicotinic acid (2942-59-8) + 3-chloro-aniline (108-42-9) → 2-<(3-chlorophenyl)amino>-3-pyridinecarboxylic acid (57978-41-3)

Conditions	Yield
With toluene-4-sulfonic acid In water for 4h; Reflux;	97%
With potassium carbonate In water at 150℃; for 3h; Green chemistry;	94%
With sodium iodide at 100 - 140℃; for 3h;	94%

tert-butyl N-[(1s,4s)-4-aminocyclohexyl]carbamate (247570-24-7) + 2-chloronicotinic acid (2942-59-8) → syn-{4-[(2-chloro-pyridine-3-carbonyl)-amino]-cyclohexyl}-carbamic acid tert-butyl ester (834868-97-2)

Conditions	Yield
Stage #1: 2-chloronicotinic acid; oxalyl dichloride With N,N-dimethyl-formamide In dichloromethane at 0 - 20℃; for 3.16667h; Stage #2: tert-butyl N-[(1s,4s)-4-aminocyclohexyl]carbamate With N-ethyl-N,N-diisopropylamine In dichloromethane for 18h;	97%

2-chloronicotinic acid (2942-59-8) + 3-methylmercaptoaniline (1783-81-9) → 2-(3-Methylsulfanyl-phenylamino)-nicotinic acid (115891-07-1)

Conditions	Yield
	96%

2-chloronicotinic acid (2942-59-8) + butan-1-ol (71-36-3) → 2-n-butoxypyridine-3-carboxylic acid (28355-23-9)

Conditions	Yield
With sodium In ethyl acetate	96%
Stage #1: butan-1-ol With sodium hydride In dimethyl sulfoxide at 0℃; for 0.5h; Stage #2: 2-chloronicotinic acid In dimethyl sulfoxide at 20℃; Stage #3: With hydrogenchloride In water; dimethyl sulfoxide

2-chloronicotinic acid (2942-59-8) + p-toluidine (106-49-0) → 2-[(4-methylphenyl)amino]pyridine-3-carboxylic acid (60645-32-1)

Conditions	Yield
With potassium carbonate In water at 150℃; for 2.5h; Green chemistry;	96%
With potassium carbonate In water at 150℃; for 1h; Microwave irradiation;	81%
With pyridine; toluene-4-sulfonic acid In water; acetone at 70℃; for 8h;

Upstream product

• 96440-05-0 2-chloro-3-ethylpyridine 
• 609-71-2 2-hydroxy-3-carboxypyridine 
• 2398-81-4 Nicotinic acid N-oxide 
• 1452-94-4 ethyl 2-chloronicotinate 
• 10026-13-8 phosphorus pentachloride 
• 10025-87-3 trichlorophosphate 
• 62969-86-2 3-ethylpyridine-2(1H)-one 
• 89-00-9 Pyridine-2,3-dicarboxylic acid 
• 49609-84-9 2-Chloronicotinoyl chloride 
• 56880-79-6 3-Ethyl-1-methyl-2-pyridon 
• 59-67-6 nicotinic acid 
• 152361-99-4 ethyl 2-chloro-2-cyano-5-oxopentanoate 
• 6602-54-6 2-chloro-3-pyridinecarbonitrile 
• 56-40-6 glycine 

Downstream Products

• 40134-18-7 methyl 2-chloropyridine-3-carboxylate 
• 609-71-2 2-hydroxy-3-carboxypyridine 
• 99973-09-8 2-hydroxy-nicotinic acid-[2]pyridylamide 
• 109255-91-6 2-(2-hydroxy-nicotinoylimino)-2H-[1,2']bipyridyl-3'-carboxylic acid 
• 35620-72-5 2-(phenylthio)nicotinic acid 
• 16344-24-4 2-(phenylamino)nicotinic acid 
• 35620-71-4 2-phenoxypyridine-3-carboxylic acid 
• 57978-48-0 2-(m-nitrophenylamino)nicotinic acid 
• 181527-55-9 2-(2,5-Dichloro-phenylsulfanyl)-nicotinic acid 
• 187658-74-8 2-(2-nitro-5-chloro)thiophenoxynicotinic acid 
• 121495-79-2 2-chloropyridine-3-carbonyl chloride hydrochloride 

Relevant articles and documents

Preparation method of 2-chloronicotinic acid

The invention relates to a preparation method of 2-chloronicotinic acid. 2-chloronicotinic acid as a product is obtained by two steps of reactions of carboxylation and chlorination of 2-hydroxypyridine in an organic solvent at a certain temperature. The method provided by the invention has the advantages of more raw material sources, obvious cost advantage, safer and more convenient preparation method, high total yield and less three wastes, especially can avoid the use of phosphine oxychloride or triphosgene, and is beneficial to industrialization.

Combining photoredox catalysis and oxoammonium cations for the oxidation of aromatic alcohols to carboxylic acids

A methodology is reported for converting alcohols to the corresponding carboxylic acids. A dual catalytic system involving a merger of photoredox catalysis and 4-acetamido-TEMPO is employed to carry out this oxidation process.

Preparation method of 2-chloronicotinic acid

The invention belongs to the field of chemical synthesis, and discloses a 2-chloronicotinic acid preparation method, which comprises: adopting 2-chloro-3-methylpyridine as a starting raw material, adopting any one of acetic acid, chloroform, acetonitrile and ethyl acetate as a solvent, adopting N-hydroxyl phthalimide as an initiator, selecting a metal salt as a catalyst, and carrying out oxygen direct oxidation to prepare 2-chloronicotinic acid, wherein the metal salt is any one of cobalt acetate, cobalt acetyl acetonate (III), manganese acetate and manganese acetyl acetonate (III). The raw materials used in the method are low in cost, the process is simple, the reaction conditions are mild, the product quality and yield reach high levels, the purity of the 2-chloronicotinic acid product can reach 98.5% or above, the yield can reach 75% or above, and the highest yield can reach 94% or so.

Safe and environment-friendly 2-chloronicotinic acid synthesis method

The invention relates to the field of synthesis of 2-chloronicotinic acid. In view of the problem that an existing method for preparing 2-chloronicotinic acid is large in wastewater amount and seriousin pollution, the invention provides a safe and environment-friendly 2-chloronicotinic acid synthesis method. The preparation method comprises the following steps: adding 3-cyanopyridine N-oxide andsolid phosgene into an organic solvent, adding a catalyst, carrying out chlorination reaction through heating reflux, cooling to room temperature after the reaction is completed, adding water, performing stirring, standing for layering, distilling an organic layer to recover a solvent, adding a decolorizing agent into a water layer, heating to 50-110 DEG C, simultaneously carrying out cyano hydrolysis and decolorizing reaction, filtering while hot after the reaction is completed, cooling filtrate to 0-5 DEG C, and performing filtering and drying to obtain 2-chloronicotinic acid with the content of 99.0% or above. Reaction conditions are mild, the operation is easy, convenient and safe, the wastewater amount is small, and the production cost is low.

Method for preparing aldehyde and acid by electrochemical dehydrochlorination of polychloromethylpyridine derivatives

The invention discloses a method for preparing aldehyde and an acid by electrochemical dechlorination of a polychloromethylpyridine derivative, the method comprises the following steps: dissolving thepolychloromethylpyridine derivative in an acetic acid and acetate- containing buffer solution to obtain an electrolytic reaction solution; taking the electrolytic reaction solution as a cathode liquid, performing electrolytic reduction dechlorination reaction at a cathode, and hydrolyzing in the solution to obtain a polychlorinated pyridylaldehyde or acid derivative. The polychloromethylpyridinederivative is shown in formula (I), and the product polychlorinated pyridylaldehyde or acid derivative is shown in formula (II): in the formula (I), m is 0, 1, 2, 3 or 4, n is 0 or 1, and R' is an easy-to-oxidize or easy-to-hydrolyze substituent. The m and the R' in the formula (II) are same as that in the formula (I), R is H or OH, no waste acid is generated in the preparation process, the easy-to-oxidize or easy-to-hydrolyze substituent contained in the polychloromethylpyridine derivative and carbon-chlorine bonds on pyridine rings are not affected, and the recovery conversion rate is high.

Preparation method of 2- novel chloronicotinic acid (by machine translation)

The method disclosed by the invention 2 - comprises the following steps: reacting the obtained :1) product with trichlorooxygen phosphorus, in the presence of 1) an acid, to give 2 - the product of 2 - the present invention ;2) in the following steps: reacting the obtained product with phosphorus oxychloride, in 2 - the presence of a ;3) base with 2) phosphorus oxychloride in the presence of a base, 2 - 2 . (by machine translation)

Process for preparation of carboxylic acid by hydrolysis of nitrile compound

The invention relates to the technical field of chemical preparation processes, in particular to a process for preparation of carboxylic acid by hydrolysis of a nitrile compound. The process includesthe steps of: 1) adding the nitrile compound into a saturated aqueous solution of salt, then adding alkali, and carrying out hydrolysis reaction to obtain a reaction solution; 2) adding acid into thereaction solution obtained in step 1), performing filtering after complete precipitation of crystals to obtain a solid mixture, and recycling the filtrate; and 3) separating the solid mixture obtainedin step 2) to obtain carboxylic acid. The method adopts the saturated aqueous solution of salt as the solvent, the nitrile compound is hydrolyzed under an alkaline condition, then acid is added for acidification, the generated salt crystals are precipitated out, the generated carboxylic acid is a solid insoluble in the solvent and is precipitated out at the same time, then filtering operation iscarried out, the generated filtrate is further used as the solvent for hydrolysis reaction of the nitrile compound, and the filtered solid is separated to obtain the salt and carboxylic acid.

Refining and purification method and drying treatment apparatus for 2-chloronicotinic acid

The invention discloses a refining and purification method and a drying treatment apparatus for 2-chloronicotinic acid. The method comprises the following steps: reacting 3-methylpyridine with chlorine to produce 2-chloro-3-trichloromethylpyridine; hydrolyzing 2-chloro-3-trichloromethylpyridine to obtain a 2-chloronicotinic acid reaction product; and purifying and drying the 2-chloronicotinic acidreaction product by using the apparatus. The apparatus is applicable to drying treatment of 2-chloronicotinic acid and has a simple structure. The refining and purification method for 2-chloronicotinic acid can greatly improve the quality and purity of a 2-chloronicotinic acid product.

Method for preparing 2-chloronicotinic acid with 2,3-pyridinedicarboxylic acid as raw material

The invention discloses a method for preparing 2-chloronicotinic acid with 2,3-pyridine dicarboxylic acid as a raw material. The preparation method comprises the following steps: in the presence of asolvent, carrying out a contact reaction on 2,3-pyridine dicarboxylic acid, an oxidant and a chlorination reagent to obtain 2-chloronicotinic acid. The method has the advantages of being short in route, easy to operate, safe, environmentally friendly and convenient for large-scale production.

New green technology for preparation of 2-chloronicotinic acid

The invention relates to a new green technology for preparation of 2-chloronicotinic acid. The technology includes: adopting nicotinic acid (I) as the raw material, conducting hydrogen peroxide N-oxidation under the action of a catalyst in a water system to obtain nicotinic acid N-oxide (II), then under the action of organic base, conducting phosphorus oxychloride chlorination to synthesize 2-chloronicotinyl chloride (III), and then performing hydrolysis and refining to obtain 2-chloronicotinic acid (IV). The method avoids the use of benzene and acetic acid, has the advantages of short process, safety and environmental protection, good product quality and high yield, is an environment-friendly green synthetic route, and is suitable for industrial production.