- Preparation method for removing methyl impurities from istradefylline
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The invention belongs to the technical field of medicinal chemistry, and particularly relates to a preparation and purification method for removing methyl impurities from istradefylline. Istradefylline is used as a raw material to prepare three high-purity demethylated impurity compounds I, II and III, the method is simple in process, easy to operate, simple in purification and high in yield, the prepared impurities are high in purity, and qualified impurity reference substances can be provided for quality control of istradefylline. The istradefylline impurity reference substance prepared by the invention can provide an important reference basis for monitoring the impurity in the research and development of an istradefylline process, improves the quality monitoring level of istradefylline, and has great significance and practical value for the development of medicinal istradefylline.
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Paragraph 0006; 0017; 0018
(2021/08/14)
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- Antidepressants
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The present invention relates to an antidepressant containing as an active ingredient a xanthine derivative or a pharmaceutically acceptable salt thereof, the xanthine derivative being represented by Formula (I) : STR1 in which R1, R2, and R3 represent independently hydrogen, lower alkyl, lower alkenyl; R4 represents cycloalkyl, --(CH2)n --R5 (in which R5 represents substituted or unsubstituted aryl or a substituted or unsubstituted heterocyclic group; and n is an integer of 0 to 4), or STR2 (in which Y1 and Y2 represent independently hydrogen, halogen or lower alkyl; and Z represents substituted or unsubstituted aryl, STR3 (in which R6 represents hydrogen, hydroxy, lower alkyl, lower alkoxy, halogen, nitro, or amino; and m represents an integer of 1 to 3), or a substituted or unsubstituted heterocyclic group); and X1 and X2 represent independently O or S.
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- Therapeutic agent for Parkinson's disease
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Agents for the treatment of Parkinson''s disease contain, as an active ingredient, a xanthine derivative or a pharmaceutically acceptable salt thereof. The xanthine derivative is represented by the formula: STR1 in which R 1, R 2 are R 3 are independently hydrogen, lower alkyl, lower alkenyl, or lower alkynyl; and R 4 represents cycloalkyl, --(CH 2) n --R 5 (in which R 5 represents substituted or unsubstituted aryl or a substituted or unsubstituted heterocyclic group; and n is an integer of 0 to 4), or STR2 in which Y 1 and Y 2 represent independently hydrogen, halogen, or lower alkyl; and Z represents substituted or unsubstituted aryl, STR3 in which R 6 represents hydrogen, hydroxy, lower alkyl, lower alkoxy, halogen, nitro, or amino; and m represents an integer of 1 to 4, or a substituted or unsubstituted heterocyclic group; and X 1 and X 2 represent independently O or S.
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