3,5-Dibromotoluene

3,5-Dibromotoluene Property

Melting point:

34-38 °C (lit.)

Boiling point:

246 °C (lit.)

Density 

1.8246 (rough estimate)

refractive index 

1.6075 (estimate)

Flash point:

>230 °F

storage temp. 

Sealed in dry,Room Temperature

solubility 

soluble in Methanol

form 

powder to crystal

color 

White to Yellow to Orange

BRN 

1928685

InChI

InChI=1S/C7H6Br2/c1-5-2-6(8)4-7(9)3-5/h2-4H,1H3

InChIKey

DPKKOVGCHDUSAI-UHFFFAOYSA-N

SMILES

C1(Br)=CC(C)=CC(Br)=C1

CAS DataBase Reference

1611-92-3(CAS DataBase Reference)

NIST Chemistry Reference

Benzene, 1,3-dibromo-5-methyl-(1611-92-3)

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-37/39

WGK Germany 

3

HazardClass 

IRRITANT

HS Code 

29039990

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.

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

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

3,5-Dibromotoluene Chemical Properties,Usage,Production

Chemical Properties

slightly yellow crystalline solid

Uses

3,5-Dibromotoluene was used in the preparation of 3,5-bis(diphenylphosphinothioyl)toluene.

General Description

3,5-Dibromotoluene is a halogenated toluene and its electric moment was evaluated.

Synthesis

The general procedure for the synthesis of 3,5-dibromotoluene from 2,6-dibromo-4-methylaniline was as follows: 1.5 L of water was added to a 5 L reaction flask and cooled to 0-5 °C in an ice bath. Under stirring conditions, 500 g of 2,6-dibromo-4-methylaniline was added in five batches, keeping the temperature between 0-5 °C to form a light yellow suspension. The temperature was controlled not to exceed 5 °C. Sodium nitrite solution (156 g of sodium nitrite dissolved in 500 mL of water) was added slowly, a small amount of reddish brown gas was released during the reaction, and the solid was gradually dissolved. After the addition was completed, stirring was continued at 0-5°C for 30 min, and the reaction solution became a transparent liquid with some foam on the surface and a small amount of black solid attached to the wall of the bottle. Subsequently, hypophosphite solution (prepared by mixing 524 g of sodium hypophosphite monohydrate and 601 g of 30% hydrochloric acid, and filtered to remove undissolved sodium chloride solid after mixing for 1 hr) was added slowly and dropwise at 0-5 °C. After completion of the dropwise addition, the reaction was maintained at 0-5°C with stirring for 5 hours. The ice bath was removed to allow the reaction temperature to rise rapidly to 15-20 °C and stirring was continued for 16 hours. The amount of diazonium salt intermediate remaining in the reaction solution was detected as 0.87% by HPLC. The reaction mixture was filtered under reduced pressure and washed with water to give 570 g of wet product. The wet product was mixed with 800 mL of methanol and heated to 50 °C with stirring until completely dissolved and layered. The heating was stopped and the stirring was cooled to 0-10 °C, and 514 g of wet product was obtained by filtration. The wet product was dried under reduced pressure at 30 °C to give 440 g of the yellow solid product 3,5-dibromotoluene (HPLC purity: 94%, yield: 93%), which could be used directly in the next step of the reaction.The NMR spectrum of 3,5-dibromotoluene is shown in Figure 2.

References

[1] Patent: CN108250046, 2018, A. Location in patent: Paragraph 0053; 0060; 0061; 0062
[2] Journal of Medicinal Chemistry, 2001, vol. 44, # 12, p. 1866 - 1882
[3] Journal of Medicinal Chemistry, 2001, vol. 44, # 12, p. 1866 - 1882
[4] Chemische Berichte, 1880, vol. 13, p. 963
[5] Chemische Berichte, 1881, vol. 14, p. 417