Preparation method of hydroxy benzene anhydride

Abstract

The invention discloses a preparation method of hydroxy benzene anhydride. The preparation method comprises the following steps: mixing nitrophthalonitrile and an organic solvent, adding alkali and nitrite, performing heating and a reflux reaction, and performing aftertreatment so as to obtain hydroxyl phthalonitrile; mixing the hydroxyl phthalonitrile and a KOH aqueous solution, performing heating, reflux and filtration, collecting filtrate, after the filtrate is cooled, regulating the pH to be 1, performing multiple extraction, taking an extraction liquid, and performing aftertreatment so as to obtain hydroxyl phthalic acid; and finally performing vacuum sublimation on the hydroxyl phthalic acid so as to obtain the hydroxy benzene anhydride. The simple preparation method of the hydroxy benzene anhydride, provided by the invention, is mild in reaction conditions, simple and convenient to operate, easy to control, low in equipment requirements and very high in yield.

Description

technical field

[0001] The invention relates to the technical field of organic synthesis, in particular to a convenient preparation method of hydroxyphthalic anhydride. Background technique

[0002] Phthalic anhydride, also known as phthalic anhydride, is a cyclic anhydride formed by intramolecular dehydration of phthalic acid. It is a white solid and is an important raw material in chemical industry, especially for the production of plasticizers.

[0003] Hydroxyphthalic anhydride is obtained by replacing the ortho or meta hydrogen of phthalic anhydride with hydroxyl. Hydroxyphthalic anhydride is an important organic intermediate, which is widely used in petrochemical, pharmaceutical, auxiliary and other fields. For example, starting from hydroxyphthalic anhydride , can synthesize a variety of monomers containing bifunctional groups, and then synthesize a series of polymers containing both ester bonds and imide rings, which have a wide range of uses.

[0004] The research ...

Examples

Embodiment 1

[0034] Embodiment 1: the preparation of 3-hydroxyphthalic anhydride:

[0035] (1) Add 103.9g (600mmol) 3-nitrophthalonitrile and 800mL dimethyl sulfoxide to the three-necked flask in sequence. After the powder is dissolved, add 85.7g (620mmol) potassium carbonate and 41.4g (600mmol) nitrous acid Sodium, heated to reflux at 160°C, reacted for 3 hours, cooled to room temperature, poured into a large amount of water, adjusted pH=3 with concentrated HCl, precipitated a yellow solid, vacuum-dried at 110°C after suction filtration, and obtained 76.4 g of 3-hydroxyphthalonitrile, Yield: 88%.

[0036] (2) Add 209.8g (3.74mol) of potassium hydroxide and 800mL of water into a three-necked flask. After exothermic dissolution, add 69.2g (480mmol) of 3-hydroxyphthalonitrile, reflux at 130°C for 90 hours, filter, and collect the filtrate , after cooling, acidify HCl to pH = 1, after cooling, add ethyl acetate to extract 3 times, take the upper ethyl acetate layer, add anhydrous magnesium s...

Embodiment 2

[0041] Embodiment 2: the preparation of 4-hydroxyphthalic anhydride:

[0042] (1) Add 103.9g (600mmol) 4-nitrophthalonitrile and 800mL dimethyl sulfoxide to the three-necked flask in turn. After the powder is dissolved, add 91.0g (660mmol) potassium carbonate and 46.0g (660mmol) nitrous acid Sodium, heated to reflux at 160°C, reacted for 5 hours, cooled to room temperature, poured into a large amount of water, adjusted the pH to 3 with concentrated HCl, and precipitated a yellow solid, after suction filtration, vacuum-dried at 110°C to obtain 73.3g of 4-hydroxyphthalonitrile , Yield: 85%.

[0043] (2) Add 230.0g (4.11mol) of potassium hydroxide and 800mL of water into a three-necked flask. After exothermic dissolution, add 69.2g (480mmol) of 4-hydroxyphthalonitrile, reflux at 100°C for 90 hours, filter, and collect the filtrate , after cooling, acidify with HCl to PH = 1, after cooling, extract with ethyl acetate 3 times, take the upper layer of ethyl acetate, add anhydrous m...

technical field

[0001] The invention relates to the technical field of organic synthesis, in particular to a convenient preparation method of hydroxyphthalic anhydride. Background technique

[0002] Phthalic anhydride, also known as phthalic anhydride, is a cyclic anhydride formed by intramolecular dehydration of phthalic acid. It is a white solid and is an important raw material in chemical industry, especially for the production of plasticizers.

[0003] Hydroxyphthalic anhydride is obtained by replacing the ortho or meta hydrogen of phthalic anhydride with hydroxyl. Hydroxyphthalic anhydride is an important organic intermediate, which is widely used in petrochemical, pharmaceutical, auxiliary and other fields. For example, starting from hydroxyphthalic anhydride , can synthesize a variety of monomers containing bifunctional groups, and then synthesize a series of polymers containing both ester bonds and imide rings, which have a wide range of uses.

[0004] The research ...

Examples

Embodiment 1

[0034] Embodiment 1: the preparation of 3-hydroxyphthalic anhydride:

[0035] (1) Add 103.9g (600mmol) 3-nitrophthalonitrile and 800mL dimethyl sulfoxide to the three-necked flask in sequence. After the powder is dissolved, add 85.7g (620mmol) potassium carbonate and 41.4g (600mmol) nitrous acid Sodium, heated to reflux at 160°C, reacted for 3 hours, cooled to room temperature, poured into a large amount of water, adjusted pH=3 with concentrated HCl, precipitated a yellow solid, vacuum-dried at 110°C after suction filtration, and obtained 76.4 g of 3-hydroxyphthalonitrile, Yield: 88%.

[0036] (2) Add 209.8g (3.74mol) of potassium hydroxide and 800mL of water into a three-necked flask. After exothermic dissolution, add 69.2g (480mmol) of 3-hydroxyphthalonitrile, reflux at 130°C for 90 hours, filter, and collect the filtrate , after cooling, acidify HCl to pH = 1, after cooling, add ethyl acetate to extract 3 times, take the upper ethyl acetate layer, add anhydrous magnesium s...

Embodiment 2

[0041] Embodiment 2: the preparation of 4-hydroxyphthalic anhydride:

[0042] (1) Add 103.9g (600mmol) 4-nitrophthalonitrile and 800mL dimethyl sulfoxide to the three-necked flask in turn. After the powder is dissolved, add 91.0g (660mmol) potassium carbonate and 46.0g (660mmol) nitrous acid Sodium, heated to reflux at 160°C, reacted for 5 hours, cooled to room temperature, poured into a large amount of water, adjusted the pH to 3 with concentrated HCl, and precipitated a yellow solid, after suction filtration, vacuum-dried at 110°C to obtain 73.3g of 4-hydroxyphthalonitrile , Yield: 85%.

[0043] (2) Add 230.0g (4.11mol) of potassium hydroxide and 800mL of water into a three-necked flask. After exothermic dissolution, add 69.2g (480mmol) of 4-hydroxyphthalonitrile, reflux at 100°C for 90 hours, filter, and collect the filtrate , after cooling, acidify with HCl to PH = 1, after cooling, extract with ethyl acetate 3 times, take the upper layer of ethyl acetate, add anhydrous m...

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