- Preparation method of 2-aminothiophene-3,4-dicarboxylic acid derivative
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The invention relates to a preparation method of a 2-aminothiophene-3,4-dicarboxylic acid derivative, and mainly solves the technical problem that the purification of the existing preparation method needs column chromatography and cannot be produced on a large scale. The preparation method comprises (1) reacting pyruvate, cyanoacetate and sulfur powder in the presence of an alkali and a solvent toobtain a reaction solution; (2) diluting the obtained reaction solution with ethyl acetate, washing with a citric acid aqueous solution, a sodium chloride aqueous solution and water in sequence to obtain a crude 2-aminothiophene-3,4-dicarboxylic acid derivative solution; (3) cooling the obtained crude 2-aminothiophene-3,4-dicarboxylic acid derivative solution to 0 to -20DEG C, and introducing a dry hydrogen chloride gas until all solids are separated out; (4) using 0 to -20DEG C ethyl acetate to wash filtered filter cake for once, and adjusting the pH to 7-8 with saturated sodium bicarbonate;(5) performing liquid separating, collecting an organic phase, washing the organic phase with an aqueous solution to obtain a pure 2-aminothiophene-3,4-dicarboxylic acid derivative solution; and (6)removing the ethyl acetate to obtain the pure 2-aminothiophene-3,4-dicarboxylic acid derivative.
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Paragraph 0011; 0014-0015
(2019/10/15)
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- Therapeutically Active Fused Pyrimidine Derivatives
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A series of monocyclic or bicyclic diamine-substituted thieno[2,3-d]pyrimidine and isothiazolo[5,4-d]pyrimidine derivatives are beneficial in the treatment and/or prevention of various human ailments, including inflammatory, autoimmune and oncological disorders; viral diseases; and organ and cell transplant rejection.
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Paragraph 0271
(2014/10/29)
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- THERAPEUTICALLY ACTIVE FUSED PYRIMIDINE DERIVATIVES
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A series of monocyclic or bicyclic diamine-substituted thieno[2,3-d]pyrimidine and isothiazolo[5,4-d]pyrimidine derivatives are beneficial in the treatment and/or prevention of various human ailments, including inflammatory, autoimmune and oncological disorders; viral diseases; and organ and cell transplant rejection.
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Page/Page column 41; 42
(2013/03/26)
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