反应详情

To a suspension 2-(3,5-dichloro-2-hydroxy-benzoylamino)-5-fluoro-indan-2-carboxylic acid ethyl ester (19) (624 mg, 1.51 mmol), anhydrous Cs2CO3 (984 mg, 3.02 mmol), and KI (50 mg, 0.30 mmol) in DMF (20 mL) is added bromocyclobutane (711 μL, 7.55 mmol). The resulting reaction suspension is covered with argon and ran in a microwave reaction: 110° C., 2 h. After the removal of DMF in vacuo, the residue is dissolved in EtOAc (50 mL) and washed with water (1×5 mL) and brine (2×5 mL). The organic layer is dried over anhydrous Na2SO4 and concentrated in vacuo. The residue is purified by flash column chromatography (120 g silica gel, gradient elution: 10%-50% EtOAc in heptane) to give a pure product (20) as white solid (365 mg, 52%).

1. customThe resulting reaction suspension
2. customran in a microwave reaction
3. custom110° C., 2 h
4. customAfter the removal of DMF in vacuo
5. dissolutionthe residue is dissolved in EtOAc (50 mL)
6. washwashed with water (1×5 mL) and brine (2×5 mL)
7. dry with materialThe organic layer is dried over anhydrous Na2SO4
8. concentrationconcentrated in vacuo
9. customThe residue is purified by flash column chromatography (120 g silica gel, gradient elution: 10%-50% EtOAc in heptane)