Some common heterocyclic compound, 6941-75-9, name is 5-Bromoisoindoline-1,3-dione, molecular formula is C8H4BrNO2, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. Safety of 5-Bromoisoindoline-1,3-dione
4-bromo phthalimide (manufactured by Tokyo Kasei Kogyo) 9.95 g (44.0 mmol) were placed in a two-necked eggplant flask 50ml was replaced with nitrogen gas.Then added iodine 5.87g (23.1mmol) and 10% fuming sulfuric acid (Yotsuhata Chemical Industry Co., Ltd.) 12ml, it was subjected to 23 hours of reaction at 90C .The reaction mixture was poured into ice cooled to room temperature, filtered through a glass filter, to give a yellow solid 12.8 g. The resulting solid was dissolved in concentrated sulfuric acid 35 ml, the reaction was carried out for 5 hours at 130C..The reaction mixture was ice-cooled, and filtered the solid precipitated by adding ice water to give a solid 13.8g of phthalic acid derivatives. Next, the resulting solid was dissolved at room temperature sodium hydroxide 3.6g aqueous solution dissolved in water 18 ml. The basic aqueous solution of acetic acid was added to adjust the pH to 3-4, filtered the white precipitate of the mono sodium salt of the phthalic acid derivative precipitated. The resulting white solid was suspended in water, to pH 1 or less with concentrated hydrochloric acid to give a white solid 6.45g again as phthalic acid derivatives. The solid was dissolved in toluene 48 ml, was added acetic anhydride 8.7g (85.7mmol), the reaction was carried out for 4 hours at 105C. To give a white solid 5.87g The reaction mixture was concentrated under reduced pressure.The solid was purified by recrystallization in toluene to give 4-bromo-5-iodo-phthalic anhydride object 5.13g of (14.5mmol) (33% yield).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 6941-75-9, its application will become more common.
Reference:
Patent; Tosoh Corporation; Watanabe, Masato; Ohashi, Tomokazu; Fujita, Takumi; (137 pag.)JP5716821; (2015); B2;,
Indoline – Wikipedia,
Indoline | C8H9N – PubChem