Product name:Coumarin
CAS:91-64-5
Molecular Formula:C9H6O2
Formula Weight:146.14
Description:
Specification:500g
Coumarin has sublimated white crystal, with citronella aroma, and slightly medicinal fragrance. Insoluble in cold water, soluble in hot water, ethanol, ether, chloroform.
Coumarin is prepared from salicylaldehyde by perkin reaction. Salicylaldehyde can be reacted with acetic anhydride using calcined potassium carbonate as catalyst. Carbonic acid and acetic anhydride were added to salicylic aldehyde and heated to 187℃. Acetic acid was evaporated at the gas phase temperature of about 120℃. Then acetic anhydride was added and reacted at 210-212℃. The coumarin product was washed with water and then distilled in vacuum. The Coumarin was then recrystallized with ethanol or isopropanol and dried at 50℃.
Coumarin is obtained by the action of o-cresol and phosphoryl chloride to obtain the intermediate o-cresol phosphate ester, which is chlorinated at 180 ° c to change methyl into -chci2, and then cyclized with sodium acetate at 160-180 ° c for 5h. If o-cresol reacts with phosgene, the intermediate o-cresol carbonate is used to complete the process: o-cresol carbonate is formed by the reaction of o-cresol sodium salt and phosgene at 60℃ and 0.15MPa. Esterification with chlorine gas at 180-185 ° c was chlorinated to a content of about 37%, equivalent to two chlorine atoms on the side chain of each cresol. Finally, Coumarin was obtained by condensation with acetic acid and acetic anhydride in the presence of pyridine or zinc oxide and cobalt oxide.