221349-58-2Relevant articles and documents
Synthesis process of ezetimibe intermediate
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, (2016/10/24)
The invention discloses a synthesis process of an ezetimibe intermediate which is (2S,3S)-2-(4-(benzyloxy)phenyl)-1-(4-fluorophenyl)-4-oxoazetidine-3-carboxaldehyde (an intermediate E6); (s)-4-phenyl-2-oxazolone and ethyl malonyl chloride as raw materials are subjected to condensation through condensation catalysis of TMSCl and TBAF to obtain an intermediate E3, the intermediate E3 and N-(4-fluorophenyl)-4-benzyloxybenzylidene amine are subjected to condensation under catalysis of titanium tetrachloride to obtain an intermediate E4, the intermediate E4 is subjected to cyclization under catalysis of BSA and FBAF to produce beta-lactam intermediate E5, and then the intermediate E5 is reduced by DIBALH into the aldehyde intermediate E6. The raw materials adopted by the process are cheap and easy to obtain, a solvent is single, the reaction time is short, the production cost is low, the yield is high, the operation of production units is simple, and the synthesis process is suitable for industrialized production.
A formal synthesis of ezetimibe via cycloaddition/rearrangement cascade reaction
Michalak, Michal,Stodulski, MacIej,Stecko, Sebastian,Mames, Adam,Panfil, Irma,Soluch, Magdalena,Furman, Bartlomiej,Chmielewski, Marek
, p. 6931 - 6936 (2011/10/08)
A formal synthesis of a powerful cholesterol inhibitor, ezetymibe 1, is described. The crucial step of the synthesis is based on Cu(I)-mediated Kinugasa cycloaddition/rearrangement cascade reaction between terminal acetylene derived from acetonide of l-glyceraldehyde and suitable C,N-diarylnitrone. The adduct with (3R,4S) configuration at the azetidinone ring, obtained with high stereoselectivity, was subsequently subjected to deprotection of the diol side chain followed by glycolic cleavage and base-induced isomerization at the C3 carbon atom to afford the (3S,4S) aldehyde, which has been already transformed into ezetimibe by the Schering-Plough group.
A PROCESS FOR THE PREPARATION OF AN ALDEHYDE BETA-LACTAM COMPOUND
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Page/Page column 31-32, (2010/09/17)
The invention relates to a process for the preparation of an aldehyde beta-lactam compound of formula (I), wherein P1 is H or a protecting group, useful in the preparation of ezetimibe, from a nitrone compound of formula (II). The nitrone compound Il is prepared by reacting 4-fluorophenylhydroxyloamine with OH- protected 4-hydroxybenzaldehyde. The nitrone compound of formula (II) is reacted with an acetylene compound of formula (III) to form a compound of formula (IV), and the compound of formula (IV), after optional deprotection, is oxidized to obtain an aldehyde of formula (V), which undergoes isomerisation to the compound of formula (I). The subject of the invention are also novel compounds of formulas (II) and (IV).
Synthesis of 3H, 14C and 13C6 labelled Sch 58235
Hesk,Bignan,Lee,Yang,Voronin,Magatti,McNamara,Koharski,Hendershot,Saluja,Wang
, p. 145 - 155 (2007/10/03)
3H-Sch 58235 was prepared at a specific activity of 29.1 Ci/mmol by Ir(COD)(Cy3P)PyPF6 catalysed exchange with tritium gas. 14C-Sch 58235 was prepared in three steps from p-hydroxy[ring-U-14C]benzaldehyde with an overall radiochemical yield of 21%. 13C6-Sch 58235 was similarly prepared in three steps from p-hydroxy[ring-U-13C6]benzaldehyde in an overall yield of 41%. Copyright
A novel one-step diastereo- and enantioselective formation of trans- azetidinones and its application to the total synthesis of cholesterol absorption inhibitors
Wu,Wong,Chen,Ding
, p. 3714 - 3718 (2007/10/03)
An efficient and practical asymmetric process was developed for the synthesis of azetidinone-based cholesterol absorption inhibitors. Key to this synthesis was the discovery of a novel one-step diastereo- and enantioselective formation of trans β-lactams starting from commercially available 3(S)-hydroxy-γ-lactone. Various trans β-lactams can be prepared in good yields and with better than 95:5 enantio- and diastereoselctivity. A Lewis acid-catalyzed aldol condensation and a highly enantioselective oxazaborolidine-catalyzed chiral reduction completes the side chain.