762266-07-9Relevant articles and documents
Preparation method of escitalopram process impurities
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Paragraph 0012-0014, (2019/01/04)
The invention relates to a preparation method of escitalopram process impurities. The escitalopram process impurities are obtained by reaction of 5-cyanophthalide with 4-fluorophenylmagnesium bromide.The process is simple and the yield is high.
PROCESS FOR THE PREPARATION OF A CYANO-ISOBENZOFURAN
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Page 15, (2008/06/13)
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-fluoro-benzoyl)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-5-isobenzofurancarbonitrile 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.