The invention discloses a refining method for
pentoxifylline recycling products. The content of impurities in the
pentoxifylline recycling products can be reduced, after the recycling products are refined, the maximum single impurities are reduced to be 0.1% or below, the total impurities are 0.5% or below, the standard of finished
pentoxifylline is met, the integral yield is improved, and the reaction cost is reduced. The refining method comprises the following steps: (1) adding water in the pentoxifylline recycling products under the condition of heating, dissolving, adding alkaline liquid to regulate a pH value to be 10-14, adding a
reducing agent, insulating, and then cooling and filtering to obtain an alkaline solution, wherein the single impurities in the pentoxifylline recycling products are less than 5%, and the total impurities in the pentoxifylline recycling products are less than 10%; (2) fully mixing the alkaline solution obtained in step (1) with an
organic solvent A, thenstanding for layering, and removing an organic phase by
evaporation to obtain
viscous liquid; and (3) adding an
organic solvent B to dissolve the
viscous liquid, adding
activated carbon, after insulating, filtering the
activated carbon, cooling filtrate to the temperature of 20 DEG C or below, and filtering and
drying to obtain pentoxifylline.