4,5-dibromophthalic acid

4,5-dibromophthalic acid Property

Melting point:

203.5-205.5 °C

Boiling point:

448.0±45.0 °C(Predicted)

Density 

2.205±0.06 g/cm3(Predicted)

storage temp. 

Sealed in dry,Room Temperature

pka

2.33±0.10(Predicted)

Appearance

White to off-white Solid

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

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

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

4,5-dibromophthalic acid Chemical Properties,Usage,Production

Synthesis

General procedure for the synthesis of 4,5-dibromophthalic acid from 1,2-dibromo-4,5-xylene: 6.5 g (0.025 mol) of 1,2-dibromo-4,5-xylene was added to 200 ml of water, stirred to form a suspension and heated to boiling. 15.8 g (0.1 mol) of potassium permanganate powder was divided equally into three equal parts. One portion of potassium permanganate was added to the reaction mixture every two hours for a total of 6 hours. Upon completion of the reaction, the mixture was cooled to room temperature and sodium bisulfite was slowly added to reduce the remaining potassium permanganate until the magenta completely disappeared. Subsequently, the pH of the reaction mixture was adjusted to above 12 with potassium hydroxide. The reaction mixture was filtered through a Brewer's funnel to obtain a clarified colorless filtrate of potassium 4,5-dibromophthalate. The residue was washed twice with 1% KOH solution and the washes were combined into the filtrate. The filtrate was slowly acidified with concentrated hydrochloric acid (18 M) to a pH approximately equal to 2, at which time a large amount of white flocculent 4,5-dibromophthalic acid precipitate precipitated. It was filtered through a Brinell funnel and the filter cake was washed with a small amount of 1% hydrochloric acid solution and then dried in a silica gel dryer. 7.3 g of a sparkling white solid was finally obtained in 90% yield.

References

[1] Patent: CN105541850, 2016, A. Location in patent: Paragraph 0034; 0035; 0036
[2] Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1980, p. 1834 - 1840
[3] Journal of the Chemical Society, 1952, p. 4615,4618
[4] J. Gen. Chem. USSR (Engl. Transl.), 1980, vol. 50, # 5, p. 907 - 915
[5] Zhurnal Obshchei Khimii, 1980, vol. 50, # 5, p. 1122 - 1131