Dimethylformamide → HCID 58017142, compound

Participants

Reaction Steps

To a solution of diethyl-5-chloro-2-oxoindoline-1,3-dicarboxylate, intermediate 50, (5.0 g, 16.04 mmol) in anhydrous N,N-dimethylformamide (80 ml) 1,8-diazabicyclo[5.4.0]undec-7-ene (2.63 ml, 17.64 mmol) was added dropwise at ambient temperature at such a rate that the internal temperature remained below 30° C. After continuous stirring at ambient temperature for one hour the solution was treated with tert-butyl bromoacetate (2.73 ml, 18.45 mmol) and stirring was allowed to continue for 72 h. Water (100 ml) was added, the product was extracted with tert-butyl methyl ether (2×50 ml), the combined extracts were washed with brine (50 ml) and dried (MgSO4) to give a red solid (7.11 g). Purification by flash chromatography (n-heptane/ethyl acetate=15%; increased up to 20%) yielded the title compound (4.00 g, 59%) as colorless solid (HPLC purity: 99%).MS (ESI+): 426.3

Provenance & Evidence