Preparation technique of p-acetyl aminophenol
A technology of acetamidophenol and p-aminophenol is applied in the preparation of carboxylic acid amides, the preparation of organic compounds, organic chemistry, etc., to achieve the effects of simple process, mild reaction conditions and pure products
Inactive Publication Date: 2011-02-16
NORTHWEST NORMAL UNIVERSITY
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Problems solved by technology
In the two-step synthesis method, the acylation method of p-aminophenol mostly adopts the acylation of acetic anhydride to obtain APAP, which generally needs to go through the process of activated carbon decolorization and pure crystallization, and the process is more complicated, so its production cost is higher
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[0038] Mix p-aminophenol and glacial acetic acid at a mass ratio of 1:6, add zinc powder with 1.1% of the mass of p-aminophenol as a catalyst and reducing agent, control the temperature at about 150°C, react at normal pressure and constant temperature for 9 hours; cool, filter and remove Unreacted zinc powder; distill the filtrate under reduced pressure to recover glacial acetic acid to obtain the off-white solid crude product; wash the crude product with deionized water several times, filter, and finally vacuum-dry at 40°C to obtain the finished APAP. Yield 88.4%, purity 98.5%. 1 HMNR (400MHz, d 6 -DMSO) δ: 9.64 (s, 1H, NH), 9.14 (s, 1H, OH), 7.30-7.33 (m, 1H, Ar-H), 6.64-6.67 (m, 1H, Ar-H), 1.96 (s, 3H, CH 3 ).
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The invention provides a preparation method of 4 acetamidophenol, which comprises mixing p-aminophenol and acetic acid at the mass ratio of 1:4-1:8, adding zinc powder at 1.0-1.4 wt% of p-aminophenol as catalyst and reducer, controlling the temperature at 130-160DEG C, and reacting for 6-11h at normal pressure and constant temperature, cooling and filtering to remove unreacted zinc powder, depressurizing and distilling the filter liquor to recover acetic acid, and obtaining crude incanus solid product, using deionized water to wash the crude white solid product, filtering and drying to obtainfinal product. The invention uses p-aminophenol as raw material, uses zinc powder as catalyst and uses acetic acid as acylation agent and reaction solvent, to acylate p-aminophenol in acetic acid to obtain the product, while the left acetic acid after the reaction can be simply treated to be circulated. The invention has simple process, low cost and high yield (90% at most), and the prepared APAPcan eliminate complex separation and purification, while the product purity can reach 98% at least.
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 new process for preparing acetaminophen with p-aminophenol and glacial acetic acid as raw materials and zinc powder 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, APAP 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, the synthesis methods of APAP...
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IPC IPC(8): C07C233/25C07C231/02
Inventor 张有明李景锋魏太保师海雄陈小春
Owner NORTHWEST NORMAL UNIVERSITY