Preparation process of p-acetaminophenol

Abstract

The invention provides a preparation technique of p-acetaminophenoxide; the technique includes the following steps: adding phenol, oxammonium hydrochloride, acetic acid and polyphosphate with mass ratio of 1 : 0.85 : 3.0 : 8.5 to 1 : 0.96 : 4.1 : 9.6 into a reactor and sealing the reactor; carrying out reflux reaction for 3.0 to 5.2h under normal pressure and constant temperature in an oil bath of 75 to 85 DEG C; cooling to the temperature of 20 to 30 DEG C; adding ice water of 10 to 15 times of the volume of the mixed matters into the reactor and adjusting pH to 3.5 to 4.5 by using ammonia; adding nitrogen into the reactor to replace air; adding sodium bisulfite of 1 to 2 times of the weight of phenol and then sealing the reactor, continuously carrying out reaction for 5.0 to 7.2h under the normal pressure and constant temperature in the oil bath of 110 to 132 DEG C, cooling, decompressing and vaporizing the solvent water, then using acetone to wash so as to filter out ammonium phosphate salt, combing the filtrate, vaporizing and recycling the acetone to obtain the crude product, using water to re-crystallize to obtain the white crystal of the p-acetaminophenoxide. The preparation technique of the invention takes the phenol, glacial acetic acid and the oxammonium hydrochloride as the raw materials, takes the polyphosphate as a catalyst, adopts one pot method to prepare the p-acetaminophenoxide and has the advantages of simple technique, mild reaction conditions, low manufacture cost and being environment friendly.

Description

technical field

[0001] The invention belongs to the field of organic chemistry, and relates to a process for preparing acetaminophen, in particular to a process for preparing paracetamol with phenol, glacial acetic acid and hydroxylamine hydrochloride as raw materials and polyphosphoric acid as a catalyst. Background technique

[0002] Acetaminophen (APAP), also known as paracetamol, is gradually replacing the previous antipyretic and analgesic drugs because of its good antipyretic and analgesic effect, rapid and long-lasting effect, small side effects on the human body, and few allergic reactions. (such as aspirin, etc.), become the preferred antipyretic and analgesic drugs in the world pharmaceutical market. In addition to being an excellent antipyretic and analgesic, paracetamol is also a synthetic intermediate for many other drugs. For example, it is used to synthesize the new expectorant drug ambroxol hydrochloride, the analgesic drug propatamol, etc.

[0003] So far,...

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