3,4-Dichloro-1,2,5-thiadiazole

3,4-Dichloro-1,2,5-thiadiazole Property

Melting point:

82-83 °C

Boiling point:

158 °C (lit.)

Density 

1.648 g/mL at 25 °C (lit.)

refractive index 

1.561

Flash point:

>100°C

storage temp. 

Keep in dark place,Sealed in dry,Room Temperature

solubility 

Soluble in chloroform and methanol.

pka

-3.82±0.10(Predicted)

form 

Oil

color 

Colorless

Sensitive 

Hygroscopic

BRN 

606585

InChI

InChI=1S/C2Cl2N2S/c3-1-2(4)6-7-5-1

InChIKey

YNZQOVYRCBAMEU-UHFFFAOYSA-N

SMILES

S1N=C(Cl)C(Cl)=N1

CAS DataBase Reference

5728-20-1(CAS DataBase Reference)

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-37/39

RIDADR 

UN2810

WGK Germany 

2

HazardClass 

6.1

PackingGroup 

III

HS Code 

29349990

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.

3,4-Dichloro-1,2,5-thiadiazole Chemical Properties,Usage,Production

Chemical Properties

Colorless liquid

Uses

3,4-Dichloro-1,2,5-thiadiazole is a chlorinated thiadiazole that is a potent inhibitors of nitrification in soil. 3,4-Dichloro-1,2,5-thiadiazole is used as a building block in the preparaton of the β-adrenergic blocking agent, Timolol.

Uses

3,4-Dichloro-1,2,5-thiadiazole has been employed:

• as guest molecule to investigate solid-state 13C NMR spectra of inclusion compounds of 2,6-dimethyl-bicyclo[3.3.1]nonane-exo-2-exo-6-diol with small organic molecules
• in preparation of [1,2,5]thiadiazol-3-yl-piperazine compounds

Synthesis Reference(s)

Tetrahedron Letters, 15, p. 1687, 1974 DOI: 10.1016/S0040-4039(01)82554-5

Synthesis

GENERAL PROCEDURE: The reaction system was cooled to -25°C under argon protection, followed by the slow dropwise addition of disulfur dichloride (S2Cl2, 0.64 mL, 8.00 mmol) to a solution of anhydrous acetonitrile (10 mL) containing o-dichloroacetaldioxime (2.0 mmol) and pyridine (0.80 mL, 10.0 mmol) while stirring was maintained. After dropwise addition, the reaction mixture was gradually warmed to room temperature and continued stirring for 1 hour, followed by heating to reflux state for 4 hours. Upon completion of the reaction, the mixture was filtered to remove insoluble material and the filtrate was concentrated under reduced pressure to remove solvent. The resulting crude product was purified by column chromatography (silica gel Merck 60, eluent was a solvent mixture of hexane/dichloromethane) to afford the target product 3,4-dichloro-1,2,5-thiadiazole.

References

[1] Tetrahedron, 2014, vol. 70, # 35, p. 5558 - 5568
[2] Journal of Organic Chemistry, 1970, vol. 35, p. 1165 - 1169