Preparation method of pentoxifylline

The invention provides a pentoxifylline preparation method, which comprises: mixing 6-bromohexanone, theobromine, an acid-binding agent and a solvent, carrying out a reaction, and collecting a solid product to obtain pentoxifylline, the acid-binding agent is selected from at least one of potassium-containing strong alkali and weak acid salt, sodium-containing strong alkali and weak acid salt and triethylamine; the solvent is selected from at least one of N, N-dimethylformamide, acetonitrile, tetrahydrofuran and dichloromethane. The specific combination of the solvent and the acid-binding agent is adopted, the reaction is facilitated, the yield of the crude pentoxifylline product can be increased, and the method is simple in operation step, easy to control and suitable for large-scale production. 本发明提供一种己酮可可碱的制备方法，制备方法包括：将6-溴己酮、可可碱、缚酸剂和溶剂混合，进行反应，收集固体产物得到己酮可可碱；所述缚酸剂选自含钾的强碱弱酸盐、含钠的强碱弱酸盐、三乙胺中的至少一种；所述溶剂选自N,N-二甲基甲酰胺、乙腈、四氢呋喃、二氯甲烷中的至少一种。本发明采用特定的溶剂和缚酸剂组合，有利于反应的进行，能够提高己酮可可碱的粗品收率，并且操作步骤简单，易于控制，适于大规模生产。