5,5'-Dibromo-2,2'-bithiophene

5,5'-Dibromo-2,2'-bithiophene Property

Melting point:

144-146 °C(lit.)

Boiling point:

318.6±37.0 °C(Predicted)

Density 

1.951±0.06 g/cm3(Predicted)

storage temp. 

Keep in dark place,Sealed in dry,Room Temperature

form 

powder to crystal

color 

White to Light yellow to Light orange

Water Solubility 

Slightly soluble in water.

InChI

InChI=1S/C8H4Br2S2/c9-7-3-1-5(11-7)6-2-4-8(10)12-6/h1-4H

InChIKey

SXNCMLQAQIGJDO-UHFFFAOYSA-N

SMILES

C1(C2SC(Br)=CC=2)SC(Br)=CC=1

CAS DataBase Reference

4805-22-5(CAS DataBase Reference)

Safety

Hazard Codes 

Xn

Risk Statements 

20/21/22

Safety Statements 

36/37-24/25

WGK Germany 

3

HS Code 

29349990

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H225Highly Flammable liquid and vapour

H315Causes skin irritation

H319Causes serious eye irritation

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P233Keep container tightly closed.

P240Ground/bond container and receiving equipment.

P241Use explosion-proof electrical/ventilating/lighting/…/equipment.

P242Use only non-sparking tools.

P243Take precautionary measures against static discharge.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

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

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

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

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P337+P313IF eye irritation persists: Get medical advice/attention.

P370+P378In case of fire: Use … for extinction.

P403+P235Store in a well-ventilated place. Keep cool.

P501Dispose of contents/container to..…

5,5'-Dibromo-2,2'-bithiophene Chemical Properties,Usage,Production

Chemical Properties

white to light yellow shiny flakes or

Uses

It is an active pharmaceutical ingredient and an OLED (organic light-emitting diode) intermediate.

Uses

A termination reagent for polymer ization

Synthesis

Using 2,2'-bithiophene (5.40 g, 32.4 mmol) as starting material, the reaction was stirred with N-bromosuccinimide (NBS, 11.57 g, 64.8 mmol, 2 eq.) in a solvent mixture of chloroform/acetic acid (1:1 v/v, 300 mL) for 4 hours at 70 °C. Upon completion of the reaction, the reaction mixture was diluted with dichloromethane (50 mL) and saturated aqueous sodium carbonate solution (100 mL). The organic phase was separated and the aqueous phase was extracted with dichloromethane (3 x 50 mL). The organic phases were combined, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to give a light yellow solid. The solid was washed with acetone to give the pure product 5,5'-dibromo-2,2'-bithiophene (1a, 10.42 g, 98% yield). To further improve the purity, it was recrystallized from tetrahydrofuran (THF). The structure of the product was confirmed by the following characterization data: 1H NMR (DMSO-d6, 600 MHz) δ: 7.23-7.22 (d, J = 3.9 Hz, 2H), 7.15-7.14 (d, J = 3.9 Hz, 2H); 13C NMR (DMSO-d6, 100 MHz) δ: 136.86, 131.60, 136.86, 131.60, 135.22, 110.84 125.22, 110.84; MS (ESI+): m/z = 324.05; UV-Vis (DMSO) λmax = 325 nm; IR (ATR): 3069 cm-1 (Ar-H stretching), 1683 cm-1 (conjugated C=C stretching), 1416 cm -1 (R1-C=C-R2 cis stretching), 1293 cm-1 (C=C bending). Elemental analysis results: calculated C 29.65, H 1.24, S 19.79; measured C 30.03, H 1.40, S 18.13.

References

[1] Bulletin of the Chemical Society of Japan, 1991, vol. 64, # 8, p. 2566 - 2568
[2] Journal of the Chinese Chemical Society, 2018, vol. 65, # 7, p. 828 - 834
[3] Tetrahedron Letters, 2010, vol. 51, # 1, p. 205 - 208
[4] Tetrahedron Letters, 2015, vol. 56, # 2, p. 368 - 373
[5] Helvetica Chimica Acta, 1996, vol. 79, # 3, p. 755 - 766