- A fexofenadine hydrochloride process for synthesizing
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The invention discloses a synthetic process of fexofenadine hydrochloride. The synthetic process of fexofenadine hydrochloride comprises the following steps of: with alpha, alpha-dimethyl phenylacetic acid as a raw material, carrying out an esterification reaction on alpha, alpha-dimethyl phenylacetic acid and absolute ethyl alcohol under the catalysis of a silica gel loaded phosphotungstic acid (PW12/SiO2) solid acid catalyst to obtain alpha, alpha-dimethyl ethyl phenylacetate; carrying out Friedel-Grafts reaction on alpha, alpha-dimethyl ethyl phenylacetate and 4-chlorobutyryl chloride to obtain alpha, alpha-dimethyl-4-(4-chloro-1-oxo butyl) ethyl phenylacetate; reducing by virtue of sodium borohydride in 95% ethyl alcohol to obtain alpha, alpha-dimethyl-4-(4-chloro-1-hydroxyl butyl) ethyl phenylacetate; and carrying out N-alkylation reaction on alpha, alpha-dimethyl-4-(4-chloro-1-hydroxyl butyl) ethyl phenylacetate and alpha, alpha-dimethyl-4-piperidine methyl alcohol in DMF (dimethyl formamide) for 24 hours at the temperature of 80 DEG C to obtain alpha, alpha-dimethyl-4-[1-hydroxyl-4-[4-(hydroxyl diphenylmethyl)-1-piperidyl]-butyl] ethyl phenylacetate, and then carrying out alkali hydrolysis and salification by virtue of hydrochloric acid, so that fexofenadine hydrochloride is obtained. The synthetic process of fexofenadine hydrochloride is high in yield and low in cost, produces less pollution and is applicable to industrial mass production.
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Paragraph 0019
(2017/02/17)
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- The synthesis of fexofenadine
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This work proposes a new simple route for fexofenadine synthesis with low cost and easily obtainable raw materials. We use benzene and methallyl as starting reactants, applying steps of Friedel-Crafts alkylation reaction, hydrolysis, oxidation, esterification reaction, and reduction reaction to obtain the intermediate product, followed by N-alkylation reaction to obtain 4-{1-hydroxy-4-[4-(hydroxydiphenyl)-piperidine]butyl}-α, α-dimethylbenzene acetate. Then, the final product fexofenadine is obtained upon hydrolysis. In the synthesis process, we constantly optimize the reaction conditions such as reaction time, reaction temperature, solvent selection, and other factors, thus improving the final yield of the target product fexofenadine to 33.51 %.
- Ronggeng, Wang,Yougui, Zhao,Guanchao, Zhang
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p. 2149 - 2155
(2013/06/05)
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- ANTIHISTAMINIC PIPERIDINE DERIVATIVES AND INTERMEDIATES FOR THE PREPARATION THEREOF
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This invention relates to novel piperidine derivatives of formula (I) and a process for the preparation thereof, wherein R1 is H or C1-C6alkyl wherein the C1-C6alkyl moiety is straight or branched; R2 is -COOH or -COOalkyl wherein the alkyl moiety has from 1 to 6 carbon atoms and is straight or branched; or stereoisomers or pharmaceutically acceptable acid addition salt thereof.
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Page/Page column 30
(2010/11/03)
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- Intermediates useful for the preparation of antihistaminic piperidine derivatives
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The present invention is related to a novel intermediates and processes which are useful in the preparation of certain antihistaminic piperidine derivatives of the formula whereinW represents —C(=O)— or —CH(OH)—;R1 represents hydrogen or hydroxy;R2 represents hydrogen;R1 and R2 taken together form a second bond between the carbon atoms bearing R1 and R2;n is an integer of from 1 to 5;m is an integer 0 or 1;R3 is —COOH or —COOalkyl wherein the alkyl moiety has from 1 to 6 carbon atoms and is straight or branched each of A is hydrogen or hydroxy; and pharmaceutically acceptable salts and individual optical isomers thereof,with the proviso that where R1 and R2 are taken together to form a second bond between the carbon atoms bearing R1 and R2 or where R1 represented hydroxy, m is an integer 0.
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Page column 56
(2010/01/30)
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- Intermediates useful for the preparation of antihistaminic piperidine derivatives
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The present invention is related to a novel intermediates and processes which are useful in the preparation of certain antihistaminic piperidine derivatives of the formula whereinW represents —C(=O)— or —CH(OH)—;R1 represents hydrogen or hydroxy;R2 represents hydrogen;R1 and R2 taken together form a second bond between the carbon atoms bearing R1 and R2;n is an integer of from 1 to 5;m is an integer 0 or 1;R3 is —COOH or —COOalkyl wherein the alkyl moiety has from 1 to 6 carbon atoms and is straight or branched each of A is hydrogen or hydroxy; andpharmaceutically acceptable salts and individual optical isomers thereof, with the proviso that where R1 and R2 are taken together to form a second bond between the carbon atoms bearing R1 and R2 or where R1 represented hydroxy, m is an integer 0.
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Page column 49
(2008/06/13)
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- Antihistaminic piperidine derivatives and intermediates for the preparation thereof
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This invention relates to novel piperidine derivatives of formula (I) and a process for the preparation thereof.whereinR1 is H or C1-C6alkyl wherein the C1-C6alkyl moiety is straight or branched;R2 is -COOH or -COOalkyl wherein the alkyl moiety has from 1 to 6 carbon atoms and is straight or branched; orstereoisomers or pharmaceutically acceptable acid addition salt thereof.
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Page column 24-25
(2010/02/05)
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- Intermediates useful for the preparation of antihistaminic piperidine derivatives
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The present invention is related to a novel intermediates and processes which are useful in the preparation of certain antihistaminic piperidine derivatives of the formula wherein W represents —C(═O)— or —CH(OH)—; R1represents hydrogen or hydroxy; R2represents hydrogen; R1and R2taken together form a second bond between the carbon atoms bearing R1and R2; n is an integer of from 1 to 5; m is an integer 0 or 1; R3is —COOH or —COOalkyl wherein the alkyl moiety has from 1 to 6 carbon atoms and is straight or branched; each of A is hydrogen or hydroxy; and pharmaceutically acceptable salts and individual optical isomers thereof, with the proviso that where R1and R2are taken together to form a second bond between the carbon atoms bearing R1and R2or where R1represented hydroxy, m is an integer 0.
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