A Continuous Base-Catalyzed Methylation of Phenols with Dimethyl Carbonate

作者：Tilstam Ulf^*

来源：Organic Process Research & Development, 2012, 16(5): 1150-1153.

DOI：10.1021/op200379j

We have found that the use of a conventional, heated, standard 316 stainless steel or steel-braided PTFE tube reactor is a good and easily scalable alternative to the use of continuous microwave-heated reactors. The heat-up is almost as fast as with microwave heating, and the reactors can easily be scaled towards large-scale production. The transfer of the reported microwave procedure to the continuous flow method went very smoothly, and we found that we could further optimize the reaction to a catalytic procedure where only 10 mol % of DBU is needed with only 3 equiv of DMC. The reaction can be run neat in cases where the starting material is soluble in DMC as phenol is, or with a small amount of DMF (2-3 vol). The reaction is efficient for different types of phenols, giving a clean reaction in high yields.

• 出版日期2012-5