Synthesis Of 7-Methoxycoumarin

7-methoxycoumarin is a kind of important organic chemical raw material andintermediate, which can be widely used as medicines, pesticides, spicery products, andother chemical industries. A convenient preparation of high-purity 7-methoxycoumarinhas been developed.The synthesis of 7-methoxycoumarin was investigated and improved in this paper.Although the process requires there reaction steps, it does offer some advantages. It usescheap raw materials, such as resorcinol, DMF and dimethyl sulfate. The yield of lastproduct is 62.4%. The melting point is 116～117℃. Many factors which affect thealkylation reaction and Perkin reaction, such as ratio of batching, reaction temperature,catalyst and reaction time have been studied. The better alkylation reaction conditions areas follows: the ratio of 2,4-dihydroxybenzaldehyde to dimethyl sulfate to potassiumcarbonate is 1:1:1, reaction 5h under refluxing temperature. The better Perkin reactionconditions are as follows: the volume of 2-hydroxy-4-methoxybenzaldehyde, aceticanhydride, sodium acetic, and DMF are 1.285g (16.9 mmol), 3.2ml(67.6 mmol),2.075g(50.7 mmol), 13 ml respectively. Reaction 5h under 180℃with N₂ protecting.The process for the production of low-cost, small pollution, will have broad marketprospects.