1255909-25-1Relevant articles and documents
Preparation method of apremilast impurity
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Paragraph 0031; 0042-0044, (2021/06/02)
The invention discloses a preparation method of an apremilast impurity, and belongs to the technical field of apremilast impurity synthesis, the method comprises the following steps: taking 3-halogenated-2-methyl benzoic acid as a starting raw material to prepare an intermediate M1 through oxidation reaction, and performing dehydration condensation on the intermediate M1 to prepare an intermediate M2; taking 3, 4-dihydroxybenzonitrile as an initial raw material, carrying out an oxygen methylation reaction to prepare an intermediate M3, sequentially carrying out nucleophilic addition, a reduction reaction and alkaline hydrolysis on the intermediate M3 to prepare an intermediate M4, carrying out an amide exchange reaction on the intermediate M2 and the intermediate M4 to prepare an intermediate M5, and carrying out a coupling reaction and acid treatment on the intermediate M5 to obtain a target product. The method has the characteristics of reasonable synthetic route, easily available raw materials, simple and easy operation, high yield and high purity, and the prepared apremilast impurity can be used as a reference substance for qualitative and quantitative research of impurities in apremilast quality research, controls the content of related substances in bulk drugs, and ensures the quality of the bulk drugs.
THIOPHENE DERIVATIVES
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Page/Page column 24, (2012/04/17)
Disclosed is a compound of formula (1), wherein R1, R2, R3, R4, R5, R6, R7 and R8 are as defined in the present application.
