2-Amino-5-chloropyridine-3-carboxylic acid

2-Amino-5-chloropyridine-3-carboxylic acid Property

Melting point:

195-197°(dec)

Boiling point:

383.3±42.0 °C(Predicted)

Density 

1.577±0.06 g/cm3 (20 ºC 760 Torr)

storage temp. 

Keep in dark place,Inert atmosphere,Room temperature

form 

solid

pka

3.98±0.10(Predicted)

Appearance

Off-white to light brown Solid

InChIKey

INERBKPRIWEQRQ-UHFFFAOYSA-N

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26

WGK Germany 

3

HazardClass 

IRRITANT

HS Code 

2936290000

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P271Use only outdoors or in a well-ventilated area.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

2-Amino-5-chloropyridine-3-carboxylic acid Chemical Properties,Usage,Production

Uses

2-Amino-6-chloronicotinic Acid is a useful synthetic intermediate. It is used in the synthesis of thiamine antagonist transketolase inhibitors. It is also used to prepare 2-aminonicotinic acid 1-oxides as inhibitors of quinolinic acid synthesis in the mammalian brain.

Synthesis

The general procedure for the synthesis of 2-amino-6-chloronicotinic acid (Inter.2) using 2,6-dichloronicotinic acid (Inter.I) as starting material is as follows: 1. 2,6-dichloronicotinic acid (Inter.I) (1 equiv.) was mixed with liquid ammonia to prepare a 0.6 M ammonia solution. 2. The suspension is transferred to a pressure vessel, sealed and slowly heated to 130°C. At this temperature, the system pressure reaches 18 bar. 3. The temperature and pressure conditions were maintained for 16 hours. 4. upon completion of the reaction, cool the mixture to room temperature. 5. carefully open the pressure vessel and pour the reaction mixture into ice-cold water (in the same volume as the volume of reactants). 6. Acidify the solution to pH 1-2 using concentrated hydrochloric acid, at which point a precipitate is formed. 7. Warm the acidic mixture to room temperature and continue stirring for 30 minutes. 8. Extract the suspension with ether (400 ml each time, 3 times). 9. The organic extracts were combined, filtered and the filtrate was concentrated under vacuum to give a white solid. 10. The resulting solid was dried over P2O5 to afford the target compound 2-amino-6-chloronicotinic acid (Inter.2) in 90% yield and 96% purity. The product can be used directly without further purification. Mass spectral data: m/z (LC-MS ESP): 173 [M + H]+, retention time R/T = 3.63 min.

References

[1] Patent: WO2016/198400, 2016, A1. Location in patent: Page/Page column 65
[2] Patent: WO2007/60404, 2007, A1. Location in patent: Page/Page column 57-58
[3] Patent: WO2008/23161, 2008, A1. Location in patent: Page/Page column 99
[4] Patent: US2009/99174, 2009, A1
[5] Bioorganic and Medicinal Chemistry Letters, 2013, vol. 23, # 5, p. 1212 - 1216