L-826141

Chemical Name: 4-[2-[3,4-Bis(difluoromethoxy)phenyl]-2-[4-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]phenyl]ethyl]-3-methylpyridine N-oxide (enantiomer 1)
项目整合开发状态: Preclinical
项目研究机构: Merck Frosst (Originator)
合成路线:Metallation of 1,4-dibromobenzene (I) followed by addition to hexafluoroacetone afforded the bis(trifluoromethyl)carbinol (II),which was subsequently protected as the trimethylsilylethoxymethyl ether (III).3,4-Dihydroxybenzaldehyde (IV) was alkylated with either chlorodifluoromethane or methyl chlorodifluoroacetate to give the bis(difluoromethyl)ether (V).Addition of either the organolithium or Grignard reagent prepared from aryl bromide (III) to aldehyde (V) furnished the diaryl carbinol (VI),which was converted to chloride (VII) by treatment with SOCl2 and diisopropyl ethylamine.Selective carbomethoxylation of 3,4-dimethylpyridine (VIII) using dimethyl carbonate and LDA afforded (IX).Condensation of chloride (VII) with the lithium anion of (IX) yielded the triarylpropionate derivative (X).Ester group hydrolysis with LiOH,followed by acidification with NH4Cl,provided the decarboxylated compound (XI).After SEM group cleavage by treatment with tetrabutylammonium fluoride,the pyridine ring of the resulting (XII) was finally oxidized to the target N-oxide.

合成路线:The diastereoselective addition of the Grignard reagent prepared from bromide (III) to the chiral acylsultam Michael acceptor (XIII) afforded the triarylpropanoylsultam intermediate (XIV).Removal of the chiral auxiliary of (XIV) by means of lithium propanethiolate,followed by decarboxylation with NaOH and then acidic treatment gave (XV).Deprotection of the SEM group of (XV) with tetrabutylammonium fluoride provided the tertiary alcohol (XVI).The pyridine ring of (XVI) was finally oxidized to the N-oxide to furnish the desired chiral compound.