反应详情

Stir a mixture of 3-[3-(3,5-Dichloro-phenyl)-4,4,4-trifluoro-but-2-enoyl]-4,5,6,7-tetrahydro-benzo[c]thiophene-1-carboxylic acid methyl ester (8.75 g, 18.9 mmol), NaOH (2.65 g, 66.1 mmol) and NH2OH—HCl (2.6 g, 37.8 mmol) in MeOH (60 mL) and water (15 mL) at room temperature for 2.5 hour. After removal of solvent under vacuum, dilute the residue with ice water (50 mL). Acidify the aqueous mixture with conc. HCl to pH=1 and extract the resultant mixture with EtOAc (50 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 50:1) to afford 3-[5-(3,5-Dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-4,5,6,7-tetrahydro-benzo[c]thiophene-1-carboxylic acid methyl ester as an orange solid (8.1 g, 93.1%). MS (m/z): 478 (M+1).

1. customAfter removal of solvent under vacuum
2. additiondilute the residue with ice water (50 mL)
3. extractionextract the resultant mixture with EtOAc (50 mL×3)
4. washThe combined organic layers are washed with brine
5. dry with materialdried over anhydrous Na2SO4
6. concentrationconcentrated under vacuum
7. customPurify the residue by silica gel chromatograph (PE:EtOAc 50:1)