Green synthesis of caffeine based on methylating reagent dimethyl carbonate and environmental friendly separating method
In this paper, a green process for the synthesis and separation of caffeine was reported. Theophylline sodium is used as the raw material, diazabicyclo[5.4.0]undec-7-ene as the catalyst, and Turkey red oil as the solvent, particularly, dimethyl carbonate was adopted in place of high toxic dimethyl sulfate to form a mixture of caffeine and by-product sodium bicarbonate. After converting sodium bicarbonate to sodium carbonate, the solubility difference between caffeine and sodium carbonate at 40°C was for the first time utilized to achieve the purpose of separating caffeine with an excellent yield of 98.4% and a purity of greater than 99.0%. Furthermore, both the reaction mother liquor and separation mother liquor can be recycled and reused during the reaction and separation processes, respectively, with little caffeine loss. No industrial waste was discharged in the process of the improved synthesis and separation, which is therefore environmental friendly.
危险品化学品经营许可证（带存储）