Dimethylformamide → tert-butyl [5-chloro-1'-[(5-methyl-3-phenylisoxazol-4-yl)methyl]-2,2'-dioxospiro[indole-3,3'-pyrrolidin]-1(2H)-yl]acetate

Participants

Reaction Steps

A suspension of tert-butyl (5-chloro-2,5′-dioxospiro[indole-3,3′-pyrrolidin]-1(2H)-yl)acetate, intermediate 41 (100 mg; 0.29 mmol) in dry DMF (5 ml) was treated with sodium hydride pract. (14.8 mg; 0.37 mmol). After stirring for 20 minutes 4-(bromomethyl)-5-methyl-3-phenylisoxazole (86.24 mg; 0.34 mmol) was added. After stirring for 1 h the solvent was evaporated to give a residue, which was dissolved in ethyl acetate. The organic phase was washed with brine, dried (MgSO4) and removed in vacuo, to give a solid residue which was purified by chromatography (silica), eluting with cyclohexane containing increasing amounts of ethyl acetate (30 to 50%), to give the title compound in 58% yield (HPLC purity 99%). MS (ESI+): 522.4; MS (ESI−): 520.2

Provenance & Evidence