147189-94-4Relevant academic research and scientific papers
Process for preparing ketone enantiomer
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, (2008/06/13)
A novel multi-step process for preparing the (4S)-enantiomer of 4-(3,4 -dichlorophenyl)-3,4-1(2H)- naphthalenone in a highly-optically pure form is disclosed. The process involved starts from the known 4-(3,4-dichlorophenyl)-4-ketobutanoic acid and proceeds through such intermediates as (1) isopropyl or tert.- butyl 4-(3,4 -dichlorophenyl)-4-ketobutanoate, (2) isopropyl or tert.-butyl 4-(3,4-dichlorophenyl)-(4R)-hydroxybutanoate, (3) isopropyl or tert.-butyl 4-(3,4-dichlorophenyl-(4R)-sulfonyloxybutanoate, (4) isopropyl or tert.-butyl 4-(3,4-dichlorophenyl)-(4R)-phenylbutanoate to finally yield the desired (4S)-4-(3,4-dichlorophenyl)-3,4-dihydro -1(2H)-naphthalenone compound in a highly-optically pure form. The latter compound, which is a (4S)-enantiomer per se, has utility as an intermediate that ultimately leads to pure cis-(1S)(4S)-N-methyl-4-(3,4-dichlorophenyl)-1,2,3,4-tetrahydro-1-naphthaleneamine (sertraline), which is a known antidepressant agent. The aforementioned isopropyl and tert.-butyl esters of 4-(3,4-dichlorophenyl)-(4R)-hydroxybutanoic acid, as well as their corresponding (4R)-methanesulfonyl, (4R)-benzenesulfonyl and (4R)-p-toluenesulfonyl derivatives, are all novel compounds, as are the aforementioned isopropyl and tert.-butyl esters of 4-(3,4-dichlorophenyl)-(4R)-phenylbutanoic acid as well as the aforesaid acid per se. These novel chiral compounds are all useful as key intermediates in the overall process of the present invention.
Synthesis of 4(S)-(3,4-dichlorophenyl)-3,4-dihydro-1(2H)-naphthalenone by SN2 cuprate displacement of an activated chiral benzylic alcohol
Quallich,Woodall
, p. 10239 - 10248 (2007/10/02)
Two routes for the preparation of 4(S)-(3,4-dichlorophenyl)-3,4-dihydro-1(2H)-naphthalenone are reported. The most efficient route generates a chiral benzylic alcohol by catalytic asymmetric oxazaborolidine reduction of a γ-ketoester that is subsequently activated and displaced in an SN2 manner with a higher order cuprate. Intramolecular Friedel-Crafts cyclization of the resulting t-butylester affords the title compound.
