Preparation technology of high purity 3-hydroxyacetophenone

Abstract

A preparation technology of high purity 3-hydroxyacetophenone comprises the following steps of: adding 38 weight portions of 3-nitroacetophenone and 37 weight portions of water into a reaction vessel, adding an iron powder to react for 10 hours, adding methanol with stirring, centrifuging a precipitate for removing water to obtain 3-aminoacephenone, pouring the 3-aminoacephenone into a diazonium kettle; adding sulfuric acid, slowly adding a sodium nitrite aqueous solution into the diazonium kettle to produce 3-diazo sulfate acetophenone, adding 3-diazo sulfate acetophenone into a hydrolysis kettle, and finally drying to obtain the pure product 3-hydroxyacetophenone. The invention has advantages of simple technology, high yield of the product and high purity. By reasonable design of the reaction steps and adjustment of charging order, the application amount of strong acid is greatly reduced; in addition, by the addition of a certain amount of methanol in the reaction, the process of the reaction can be accelerated and the synthesis quality can be raised. According to statistics, the overall yield of the technology can reach over 92%; compared with other production technologies, the technology provided by the invention enables the product cost to decrease by more than 40%, and is environmentally friendly.

Description

Technical field

[0001] The present invention relates to a production technology of 3-hydroxyacetophenone, and in particular to a preparation technology of high-purity 3-hydroxyacetophenone. Background technique

[0002] 3-Hydroxyacetophenone (m-hydroxyacetophenone) is an important intermediate for the preparation of new medicine phenylephrine. The existing production process is as follows:

[0003] a. Add 3-nitroacetophenone and water to the reaction tank, add iron powder while stirring, slowly add hydrochloric acid, heat to 90°C and reflux for 6 to 8 hours, cool to 30°C, and add hydrochloric acid to make the reaction solution strong. Acidic, then filter, take the filtrate and add ammonia water until it becomes weakly alkaline, then precipitate the solid matter, filter the solid matter to obtain 3-aminoacetophenone;

[0004] b. Add water and concentrated hydrochloric acid into the reaction pot, add 3-aminoacetophenone while stirring, then lower the temperature to 5-10°C, a...

Examples

Embodiment 1

[0014] Example 1: Add 36 parts by weight of 3-nitroacetophenone, 0.03 parts by weight of methanol and 36 parts by weight of water into the reaction kettle, and then slowly add 22 parts by weight of iron powder to react for 10 hours after heating to 95°C After the filtrate enters the receiving tank, it is gradually cooled to 30°C after 10 hours. The precipitate is centrifuged to remove water and 3-aminoacetophenone is obtained (the centrifugal water is fully recovered and recycled as the reaction water for the next feeding ); Pour the obtained 3-aminoacetophenone into the diazonium kettle, add 8 parts by weight of 98% sulfuric acid, cool to 10°C, and then slowly add 8 parts by weight of sodium nitrite aqueous solution to the diazonium kettle After adding in 15 hours, 3-diazosulfate acetophenone is obtained; add 19 parts by weight of water to the hydrolysis kettle, and then increase the temperature to 95° C. to obtain 3-diazosulfate acetophenone Slowly added to the hydrolysis ket...

Embodiment 2

[0015] Example 2: Add 38 parts by weight of 3-nitroacetophenone, 0.03 parts by weight of methanol and 37 parts by weight of water into the reaction kettle, and slowly add 21 parts by weight of iron powder to react for 10 hours after heating to 95°C After the filtrate enters the receiving tank, it is gradually cooled to 30°C after 10 hours. The precipitate is centrifuged to remove water and 3-aminoacetophenone is obtained (the centrifugal water is fully recovered and recycled as the reaction water for the next feeding ); Pour the obtained 3-aminoacetophenone into the diazonium kettle, add 6 parts by weight of 98% sulfuric acid, cool to 5°C, and then slowly add 7 parts by weight of sodium nitrite aqueous solution to the diazonium kettle After adding in 15 hours, 3-diazosulfate acetophenone was prepared; 18 parts by weight of water was added to the hydrolysis kettle, and then the temperature was raised to 95°C, and the obtained 3-diazosulfate acetophenone The ketone was slowly add...

Embodiment 3

[0016] Example 3: Add 37 parts by weight of 3-nitroacetophenone, 0.04 parts by weight of methanol and 38 parts by weight of water into the reaction kettle, and slowly add 20 parts by weight of iron powder to react for 10 hours after heating to 95°C After the filtrate enters the receiving tank, it is gradually cooled to 30°C after 10 hours. The precipitate is centrifuged to remove water and 3-aminoacetophenone is obtained (the centrifugal water is fully recovered and recycled as the reaction water for the next feeding ); Pour the obtained 3-aminoacetophenone into the diazonium kettle, add 7 parts by weight of 98% sulfuric acid, cool to 8°C, and then slowly add 6 parts by weight of sodium nitrite aqueous solution to the diazonium kettle After adding in 15 hours, 3-diazosulfate acetophenone is obtained; add 17 parts by weight of water to the hydrolysis kettle, and then increase the temperature to 95° C. to obtain 3-diazosulfate acetophenone Slowly add to the hydrolysis kettle, aft...

Technical field

[0001] The present invention relates to a production technology of 3-hydroxyacetophenone, and in particular to a preparation technology of high-purity 3-hydroxyacetophenone. Background technique

[0002] 3-Hydroxyacetophenone (m-hydroxyacetophenone) is an important intermediate for the preparation of new medicine phenylephrine. The existing production process is as follows:

[0003] a. Add 3-nitroacetophenone and water to the reaction tank, add iron powder while stirring, slowly add hydrochloric acid, heat to 90°C and reflux for 6 to 8 hours, cool to 30°C, and add hydrochloric acid to make the reaction solution strong. Acidic, then filter, take the filtrate and add ammonia water until it becomes weakly alkaline, then precipitate the solid matter, filter the solid matter to obtain 3-aminoacetophenone;

[0004] b. Add water and concentrated hydrochloric acid into the reaction pot, add 3-aminoacetophenone while stirring, then lower the temperature to 5-10°C, a...

Examples

Embodiment 1

[0014] Example 1: Add 36 parts by weight of 3-nitroacetophenone, 0.03 parts by weight of methanol and 36 parts by weight of water into the reaction kettle, and then slowly add 22 parts by weight of iron powder to react for 10 hours after heating to 95°C After the filtrate enters the receiving tank, it is gradually cooled to 30°C after 10 hours. The precipitate is centrifuged to remove water and 3-aminoacetophenone is obtained (the centrifugal water is fully recovered and recycled as the reaction water for the next feeding ); Pour the obtained 3-aminoacetophenone into the diazonium kettle, add 8 parts by weight of 98% sulfuric acid, cool to 10°C, and then slowly add 8 parts by weight of sodium nitrite aqueous solution to the diazonium kettle After adding in 15 hours, 3-diazosulfate acetophenone is obtained; add 19 parts by weight of water to the hydrolysis kettle, and then increase the temperature to 95° C. to obtain 3-diazosulfate acetophenone Slowly added to the hydrolysis ket...

Embodiment 2

[0015] Example 2: Add 38 parts by weight of 3-nitroacetophenone, 0.03 parts by weight of methanol and 37 parts by weight of water into the reaction kettle, and slowly add 21 parts by weight of iron powder to react for 10 hours after heating to 95°C After the filtrate enters the receiving tank, it is gradually cooled to 30°C after 10 hours. The precipitate is centrifuged to remove water and 3-aminoacetophenone is obtained (the centrifugal water is fully recovered and recycled as the reaction water for the next feeding ); Pour the obtained 3-aminoacetophenone into the diazonium kettle, add 6 parts by weight of 98% sulfuric acid, cool to 5°C, and then slowly add 7 parts by weight of sodium nitrite aqueous solution to the diazonium kettle After adding in 15 hours, 3-diazosulfate acetophenone was prepared; 18 parts by weight of water was added to the hydrolysis kettle, and then the temperature was raised to 95°C, and the obtained 3-diazosulfate acetophenone The ketone was slowly add...

Embodiment 3

[0016] Example 3: Add 37 parts by weight of 3-nitroacetophenone, 0.04 parts by weight of methanol and 38 parts by weight of water into the reaction kettle, and slowly add 20 parts by weight of iron powder to react for 10 hours after heating to 95°C After the filtrate enters the receiving tank, it is gradually cooled to 30°C after 10 hours. The precipitate is centrifuged to remove water and 3-aminoacetophenone is obtained (the centrifugal water is fully recovered and recycled as the reaction water for the next feeding ); Pour the obtained 3-aminoacetophenone into the diazonium kettle, add 7 parts by weight of 98% sulfuric acid, cool to 8°C, and then slowly add 6 parts by weight of sodium nitrite aqueous solution to the diazonium kettle After adding in 15 hours, 3-diazosulfate acetophenone is obtained; add 17 parts by weight of water to the hydrolysis kettle, and then increase the temperature to 95° C. to obtain 3-diazosulfate acetophenone Slowly add to the hydrolysis kettle, aft...

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