- PROCESS FOR PREPARATION OF APREMILAST
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The present invention relates to a process for preparation of apremilast. The present invention relates to p-xylene solvate of apremilast and process for its preparation.
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Paragraph 00114; 00132
(2017/03/14)
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- Method for preparing 3-aminophthalic acid
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The invention discloses a method for preparing 3-aminophthalic acid by means of carrying out hydrogenation reduction on 3-nitrophthalic acid in aqueous solution. The method includes generating sodium salt solution under the effects of the 3-nitrophthalic acid and sodium hydroxide solution; carrying out reduction on nitro by the aid of hydrogen under catalytic effects of palladium on carbon to obtain amino. The hydrogen is used as a reducing agent. The method has the advantages that the 3-aminophthalic acid with the yield of 95% and the purity higher than 98% can be obtained by the aid of the method; the method can be implemented easily and feasibly and is low in production cost and little in environmental pollution, technological processes are short, and products are good in purity and high in yield.
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Paragraph 0008
(2017/09/01)
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- Preparation method of Apremilast and intermediate
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The invention provides a preparation method of Apremilast and its intermediate. The invention provides an Apremilast intermediate as shown in the formula III. According to the preparation method, the compound as shown in the formula III reacts with methanesulfinate to obtain a compound as shown in the formula IV; the compound as shown in the formula IV undergoes reductive amination to obtain a compound as shown in the formula V; the compound as shown in the formula V and asymmetry acid undergo salifying to obtain a compound as shown in the formula VI; and the compound as shown in the formula VI reacts with 3-acetamido-phthalic anhydride to obtain Apremilast. By the method for synthesizing Apremilast, usage of an n-butyllithium hexane solution can be avoided. Production cost is reduced, and operation process is convenient. In addition, safety in the industrial production is raised to a great extent, and the preparation method is more suitable for industrial continuous production. According to the preparation method of 3-acetamido-phthalic anhydride, yield is raised to 81%. As the yield is high, the method provided by the invention is extremely suitable for industrial production of Apremilast.
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Paragraph 0064; 0065; 0066
(2016/10/07)
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- Acrylamide copolymers containing (meth)acrylamide benzene dicarboxylic units
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New acrylamide copolymers formed by (meth)acrylamide benzene dicarboxylic monomer units in accordance with the following formula: STR1 wherein R is H or CH3 ; X is H or an alkaline metal or NH4 ; and wherein the COOX groups may be in ortho-, meta- or para- position in relation to each other, preferably being in ortho- position to each other; and of (meth)acrylamide monomer (II) units.
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- Acrylamide copolymers containing (meth)acrylamide benzene dicarboxylic units
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[From equivalent EP0434145A2] New acrylamide copolymers formed by (met)acrylamide benzene dicarboxylic monomer units in accordance with the following formula: ψψ ψwherein R is H or CH3; X is H or an alcaline metal or NH4; and wherein the COOX groups may be in ortho-, meta- or para- position in relation to each other, preferably being in ortho- position to each other; and of (met)acrylamide monomer (II) units.ψ
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