2,6-Dichloro-3-(trifluoromethyl)pyridine

2,6-Dichloro-3-(trifluoromethyl)pyridine Property

Melting point:

194 °C

Boiling point:

194-196 °C(lit.)

Density 

2.008 g/mL at 25 °C(lit.)

refractive index 

n20/D 1.4850(lit.)

Flash point:

218 °F

storage temp. 

Keep in dark place,Sealed in dry,Room Temperature

pka

-4.84±0.10(Predicted)

Appearance

Colorless to light yellow Liquid

BRN 

1570287

InChI

InChI=1S/C6H2Cl2F3N/c7-4-2-1-3(5(8)12-4)6(9,10)11/h1-2H

InChIKey

UPWAAFFFSGQECJ-UHFFFAOYSA-N

SMILES

C1(Cl)=NC(Cl)=CC=C1C(F)(F)F

CAS DataBase Reference

55304-75-1(CAS DataBase Reference)

Safety

Hazard Codes 

T,Xi

Risk Statements 

25-36/37/38

Safety Statements 

26-36/37-45

RIDADR 

UN 2810 6.1/PG 3

WGK Germany 

3

Hazard Note 

Harmful/Irritant

HazardClass 

6.1

PackingGroup 

III

HS Code 

29333990

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H300Fatal if swallowed

H302Harmful if swallowed

H312Harmful in contact with skin

H315Causes skin irritation

H319Causes serious eye irritation

H331Toxic if inhaled

H335May cause respiratory irritation

Precautionary statements

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

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

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

P301+P310IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician.

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

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

P405Store locked up.

2,6-Dichloro-3-(trifluoromethyl)pyridine Chemical Properties,Usage,Production

Chemical Properties

Colorless liquid

Uses

2,6-Dichloro-3-(trifluoromethyl)pyridine is a fluorine-containing pyridine derivative that can be used in cross-coupling reactions of polyhalogenated heterocycles and in the preparation of other aryl pyridines.

Synthesis

The general procedure for the synthesis of 2,6-dichloro-3-(trifluoromethyl)pyridine from (trifluoromethyl)trimethylsilane and 2,6-dichloro-3-iodopyridine is as follows: Step 1: Potassium fluoride (2.24 g, 38.5 mmol) and copper(I) iodide (7.33 g, 38.5 mmol) were weighed in a flask and the mixture was heated using a gas burner while gently shaking under high vacuum until the contents changed to light yellowish green color. After cooling to room temperature, anhydrous N,N-dimethylformamide (50 mL) and anhydrous tetrahydrofuran (10 mL) were added, followed by trimethyl(trifluoromethyl)silane (5.5 mL, 35 mmol). The mixture was heated to 50 °C and stirred for 21 hours. A mixed solution of 2,6-dichloro-3-iodopyridine (9.59 g, 35.0 mmol) in anhydrous N,N-dimethylformamide (10 mL) and anhydrous tetrahydrofuran (20 mL) was added dropwise at 50 °C to the above reaction mixture. After continuing to stir at 50 °C for 21 hours, trimethyl(trifluoromethyl)silane (0.55 mL, 3.5 mmol) was added and the mixture was stirred for 24 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, poured into 12% ammonia and the mixture was extracted with ether three times. The combined organic layers were washed sequentially with 12% ammonia, 1 M hydrochloric acid, saturated aqueous sodium bicarbonate and saturated brine, dried with anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: dichloromethane:hexane=1:4) to afford 2,6-dichloro-3-(trifluoromethyl)pyridine (7.32 g, 97.3% yield).

References

[1] Patent: WO2009/145360, 2009, A1. Location in patent: Page/Page column 111-112