C−F Bond Cleavage by Intramolecular S<sub>N</sub>2 Reaction of Alkyl Fluorides with O- and N-Nucleophiles
作者:Laijun Zhang、Wei Zhang、Jun Liu、Jinbo Hu
DOI:10.1021/jo802819p
日期:2009.4.3
The nucleophilicsubstitution of alkyl fluorides was achieved in the intramolecular reactions with O- and N-nucleophiles. The intramolecular defluorinative cyclization reaction was influenced by the nature of nucleophiles, the size of the ring to be formed, and the comformational rigidity of the precursors. Intermolecular nucleophilicsubstitution reactions of alkyl fluorides under similar reaction
在与O-和N-亲核试剂的分子内反应中实现了烷基氟化物的亲核取代。分子内脱氟环化反应受亲核试剂的性质,要形成的环的大小以及前体的构象刚性的影响。发现在相似的反应条件下烷基氟化物的分子间亲核取代反应是困难的。当前C-F键断裂反应的立体化学研究显示出完全的构型反转,这支持了分子内S N 2反应机理。
[EN] PROCESS FOR THE PREPARATION OF A CYANO-ISOBENZOFURAN<br/>[FR] PROCEDE POUR PREPARER UN CYANO-ISOBENZOFURANE
申请人:ADORKEM TECHNOLOGY SPA
公开号:WO2004080988A1
公开(公告)日:2004-09-23
A process for the preparation of citalopram and the pharmaceutically acceptable salts therof is disclosed by reacting 5-cyanophthalide with a 4-fluorophenyl magnesium halide, reducing the 3-hydroxymethyl-4-(4-fluorobenzoyl)benzonitrile with an agent reducing ketones to alcohols, submitting the thus-obtained 3-hydroxymethyl-4- [(4-fluorophenyl)hydroxymethyl) benzonitrile to a cyclization reaction to give 1-(4-fluorophenyl)-1,3-dihydro-5isobenzofurancarbonitrile without 1,1-bis(4-fluorophenyl)-1,3-dihydro-5- isobenzofurancarbonitrile and treating 1,1-bis(4 fluorophenyl)-1,3-dihydro-5- isobenzofurancarbonitrile with a 3-(dimetylamino)propyl halide in the presence of a base.
[EN] IMPROVED PROCESS FOR THE PREPARATION OF 5-SUBSTITUTED-1-(4-FLUOROPHENYL)-1,3-DIHYDROISOBENZOFURANS<br/>[FR] PROCEDE AMELIORE DE PREPARATION DE 1-(4-FLUOROPHENYL)-1,3-DIHYDROISOBENZOFURANES 5-SUBSTITUES
申请人:JUBILANT ORGANOSYS LTD
公开号:WO2004020425A1
公开(公告)日:2004-03-11
The present invention provides a process for the preparation of a 5-substituted-l-(4-fluorophenyl)-1,3-dihydro-isobenzofuran of Formula (2), an intermediate for the manufacture of citalopram, which process comprises: (a) carrying out a Grignard reaction on a corresponding 5-substituted phthalide of Formula (3) in a co-solvent system, comprising adding (i) prepared 4-fluorophenyl magnesium halide in an ether solvent to (ii) the 5-substituted phthalide in a suitable organic co-solvent to the ether solvent, to form a corresponding 4-substituted-2-hydroxymethyl-4'-fluorobenzophenone of Formula (4); (b) carrying out a ketone reduction of the 4-substituted-2-hydroxymethyl-4'-fluorobenzophenone of Formula (4) following the Grignard reaction, to form a corresponding 4-substituted-2-hydroxymethylphenyl- 1-(4-fluorophenyl) methanol of Formula (5); and (c) carrying out a cyclisation reaction on the 4-substituted-2 hydroxymethylphenyl- 1-(4-fluorophenyl) methanol of Formula (5) following the reduction reaction, to form said intermediate of Formula (2); wherein R represents Br or CN.
[EN] METHOD FOR THE PREPARATION OF CITALOPRAM<br/>[FR] PROCEDE SERVANT A PREPARER CITALOPRAM
申请人:LUNDBECK & CO AS H
公开号:WO2001068630A1
公开(公告)日:2001-09-20
The invention relates to a method for the preparation of citalopram comprising, in either order, subjecting a compound of formula (III) wherein Y is a cyano group or a group which may be converted to a cyano group, R is hydrogen, -O-R1, NH2, NHCH3 or -N(CH3)2 wherein R1 is selected from hydrogen, alkyl, alkenyl, alkynyl and optionally alkyl substituted aryl or aralkyl; to i) reduction of the double bond in the side chain of formula -CH=CH-COR: ii) conversion of the group -COR or a reduced form thereof to a dimethylaminomethyl group; and iii) if Y is not cyano, conversion of the group Y to a cyano group; followed by isolation of citalopram base or a pharmaceutically acceptable acid addition salt thereof.
Novel N-(3-hydroxy-4-pipridinyl)benzamides and derivatives thereof, said compounds being used as stimulators of the motility of the gastro-intestinal system.