Reference of 1074-24-4, In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 1074-24-4 as follows.
Iodine (78 mg, 0.33 mmol) was added to p-xylene (6.13 mL, 50.0 mmol), the mixture was cooled to 0 °C, and bromine (5.20 mL, 101 mmol) was added dropwise over 10 min. The ice bath was removed and the reaction stirred at rt for 16 h in the absence of light. The reaction was quenched with 20percent aq. KOH and stirred for 15 min while the solution became colorless. The solid precipitate was filtered and rinsed 2 x with 100 mL of H2O. The solids were recrystallized in ethanol to afford a white solid (9.19 g, 70percent). 1H NMR (CDCl3): delta 7.40 (s, 2H), 2.34 (s, 6H). 1,4?dibromo-2,5-dimethylbenzene (5.93 g, 22.5 mmol) and KMnO4 (15.72 g, 99.5 mmol) were added to 80 mL of t-BuOH:H2O (1:1). Celite (14 g) was added to the flask and the reaction was refluxed for 18 h. The reaction mixture was cooled to rt, filtered over celite and the filter was washed with hot H2O (100mL) and EtOAc (50mL). The filtrate was then acidified to pH=1 with conc. HCl. The white suspension was then extracted 3x with 100 mL of EtOAc. The combined organic extracts were dried over MgSO4 and excess solvent was removed under vacuum to obtain a white solid (3.06 g, 42percent) which was not purified further. 1H NMR (DMSO-d6): delta 8.01 (s, 2H). 2,5?dibromoterephthalic acid (2.04 g, 6.30 mmol) dissolved in 35 mL of MeOH and refluxed for 30 min. Thionyl chloride (9.00 mL, 124 mmol) was then carefully added and the reaction was refluxed 12 hours. The reaction flask was cooled to room temperature, 50 mL of water was carefully added, and the reaction was extracted 3x with 75 mL of Et2O. The combined organics were washed with 3 x with 50 mL of sat. NaHCO3 and dried with MgSO4. The solvent was removed under vacuum and the solids recrystallized in MeOH to yield a white crystalline solid (1.65g, 74percent), mp = 134-136 C (lit.3 mp 134-137 C). 1H NMR (CDCl3): delta 8.06 (s, 2H), 3.96 (s, 6H). The 1H NMR matches the known spectrum.3
According to the analysis of related databases, 1074-24-4, the application of this compound in the production field has become more and more popular.
Reference:
Article; Dressler, Justin J.; Miller, Sarah A.; Meeuwsen, Brian T.; Riel, Asia Marie S.; Dahl, Bart J.; Tetrahedron; vol. 71; 2; (2015); p. 283 – 292;,
Bromide – Wikipedia,
bromide – Wiktionary