- Preparation method of flavoxate hydrochloride coupled impurity
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The invention provides a preparation method of a flavoxate hydrochloride coupled impurity. The preparation method comprises the following steps: with a compound 2 (R is methyl, ethyl or hydrogen atom) as an initial material, performing a coupling reaction on two molecules first and then constructing a benzene ring branch chain structure, or constructing a branch chain structure and then performing coupling. By obtaining the coupled impurity, the impurity spectrum of flavoxate hydrochloride is clearer, and an analytical method is more accurate by inspecting the degree of separation of impurities, so that the quality of flavoxate hydrochloride active ingredient is further improved, and the curative effect and the safety are guaranteed.
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Paragraph 0014; 0023
(2017/09/18)
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- Halo-containing 3-methylflavone-8-carboxylic acid derivatives
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This invention relates to derivatives of 3-methylflavone-8-carboxylic acid represented by the formula (1) STR1 wherein R represents a hydrogen atom, a lower alkyl group or a group STR2 (wherein R1 and R2 represent a lower alkyl group or R1 and R2, when taken together with the nitrogen atom to which they are attached, may form a heterocyclic ring with or without an intervening hetero atom, and n is an integer of 1 to 4), and X represents a halogen atom, which are useful as intermediates. This invention also relates to processes for preparing the same.
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