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ChemicalBook CAS DataBase List 7-Diethylamino-4-methylcoumarin
91-44-1

7-Diethylamino-4-methylcoumarin synthesis

10synthesis methods
-

Yield:91-44-1 95%

Reaction Conditions:

with acetic anhydride;ammonium chloride;zinc at 127 - 135;Inert atmosphere;Large scale;Reagent/catalyst;Temperature;

Steps:

1-8 Example 1

General procedure: Put 280kg m-hydroxy-N,N-diethylaniline and 330kg into the 2000L glass-lined reactorEthyl acetoacetate, 2kg zinc powder, 2kg ammonium chloride, 2kg acetic anhydride, nitrogen protection in the kettle, start stirring and heating to raise the temperature to between 127-135°C, which is specifically set at 130°C in this embodiment. The ethanol and water produced by the reaction were distilled out while the reaction was carried out, and the reaction was kept at 130-134° C. for 3-5 hours after no distillate, specifically 4 hours in this embodiment. After the heat preservation is completed, add 250kg of glacial acetic acid and 250kg of water to the kettle, stir and cool to 0°C, spin dry to obtain the crude product and mother liquor.Put the previous batch of crude product into a 2000L glass-lined reactor, add 2-3 times the mass of methanol of m-hydroxy-N,N-diethylaniline, in this example 600kg of methanol, 10kg of activated carbon, and decolor at normal temperature and reflux for 1 hour , Filtered into another 2000L glass-lined reactor, stirred and cooled to 10°C, spin-dried and dried to obtain 372kg of finished product, melting point 74-76°C, content, purity 99.5%, yield 95%, the mother liquor was recycled for the next batch of methanol.The yield is calculated on the basis of the starting main raw material m-hydroxy-N,N-diethylaniline and the molar content of the control. Detection method (HPLC method: chromatographic column C18, 4.6*200mm; column temperature, room temperature; column pressure, 9Mpa; detector, UV254; mobile phase, methanol; flow rate, 1mL/min).

References:

CN111548337,2020,A Location in patent:Paragraph 0022-0041

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