Methyl 3-acetyl-5,6-dihydro-4H-cyclopenta[c]thiophene-1-carboxylate → 3-[3-(3,5-Dichloro-4-fluoro-phenyl)-4,4,4-trifluoro-3-hydroxy-butyryl]-5,6-dihydro-4H-cyclopenta[c]thiophene-1-carboxylic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

Add a solution of LiHDMS (1M in THF, 75 mL, 75 mmol) to a suspension of 3-acetyl-5,6-dihydro-4H-cyclopenta[c]thiophene-1-carboxylic acid methyl ester (14.0 g, 62.5 mmol) in dry THF (200 mL) at −78° C. under N2. After stirring at room temperature for 1.5 h, add 1-(3,5-dichloro-4-fluoro-phenyl)-2,2,2-trifluoro-ethanone (17.9 g, 68.7 mmol) in dry THF (100 mL) to the reaction mixture and stir the resultant mixture at the same temperature for additional 2 hours. Quench the reaction with saturated NH4Cl aqueous solution. Extract the aqueous mixture with EtOAc (100 mL×3). The combined organic layers are washed with brine, dried over anhydrous Na2SO4 and concentrated under vacuum. Purify the residue by silica gel chromatograph (PE:EtOAc 15:1) to afford 3-[3-(3,5-Dichloro-4-fluoro-phenyl)-4,4,4-trifluoro-3-hydroxy-butyryl]-5,6-dihydro-4H-cyclopenta[c]thiophene-1-carboxylic acid methyl ester as an orange solid (27 g, 89.3%). MS (m/z): 486 (M+1).

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