- Preparation method of levocetirizine
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The invention provides a preparation method of levocetirizine. The preparation method comprises following steps: carrying out a reaction on a compound represented by a formula (I) under the action ofa reduction system and L-tartaric acid to obtain a compound represented by a formula (II); and reacting the compound shown in a formula (II) with a compound shown in a formula (III) under the action of NaH, N,N-dimethyl formamide and tetrabutyl ammonium bromide to obtain levocetirizine. The levocetirizine is prepared by taking the compound shown by the formula (I) and the compound shown by the formula (III) as raw materials, at first, the compound shown by the formula (I) is de-protected and then racemized to obtain the compound shown by the formula (II); and the compound shown by the formula(II) and the compound shown by the formula (III) carry out reactions to obtain levocetirizine. The provided method is short in reaction route, the yield can reach 54% or above, and the purity can reach 99.65% at most.
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- PROCESSES FOR PREPARING LEVOCETIRIZINE AND PHARMACEUTICALLY ACCEPTABLE SALTS THEREOF
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Processes for preparing levocetirizine dihydrochloride.
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Page/Page column 24
(2009/06/27)
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- Asymmetric synthesis of cetirizine dihydrochloride
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Practical route technology for the preparation of (S)-cetirizine·2HCl via diastereoselective organometallic addition to N-tert-butanesulfinyl aldimines is disclosed.
- Pflum, Derek A,Krishnamurthy, Dhileepkumar,Han, Zhengxu,Wald, Stephen A,Senanayake, Chris H
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p. 923 - 926
(2007/10/03)
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- Enantiomers of 1-[(4-chlorophenyl)phenylmethyl]-4-[(4-methylphenyl) sulfonyl]piperazine
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Levorotatory and dextrorotatory enantiomers of 1-[(4-chlorophenyl)phenylmethyl]-4-[(4-methylphenyl)sulfonyl]piperazine of the formula STR1 their preparation and use for the preparation of substantially optically pure enantiomers of 1-[(4-chlorophenyl)phenylmethyl]piperazine, which are themselves valuable intermediate products for the preparation of optically active therapeutic compounds having a very high degree of optical purity.
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- A novel synthesis of the enantiomers of an antihistamine drug by piperazine formation from a primary amine
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An enantioselective synthesis of each enantiomer of the antihistamine drug 2-(2-{4-[(4-chlorophenyl)phenylmethyl]-1-piperazinyl}ethoxy)acetic acid dihydrochloride (1) is described, involving the preparation of the benzhydrylpiperazine portion of the molecule from reaction of each enantiomer of 4-chlorobenzhydrylamine with N,N-bis(2-chloroethyl)-4-methylbenzenesulfonamide. A modification of standard toluenesulfonamide deprotection with hydrogen bromide in acetic acid was introduced, substituting 4-hydroxybenzoic acid for phenol.
- Opalka,D'Ambra,Faccone,Bodson,Cossement
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p. 766 - 768
(2007/10/02)
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