Oxalyl chloride → N-(5-(3,5-Difluorobenzoyl)-1-trityl-1H-indazol-3-yl)-4-(4-methylpiperazin-1-yl)-2-nitrobenzamide

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Reaction Steps

To a suspension of 4-(4-methyl-piperazin-1-yl)-2-nitro-benzoic acid hydrochloride (1.5 g, 4.97 mmol) in dry tetrahydrofuran (80 mL) were added oxalyl chloride (1.4 mL, 19.9 mmol) and N,N-dimethylformamide (1-2 drops). The mixture was stirred at room temperature overnight and then evaporated to dryness. The resulting crude acyl chloride was taken-up with toluene and evaporated again then dissolved in dry tetrahydrofuran (180 mL). A solution of (3-amino-1-trityl-1H-indazol-5-yl)-(3,5-difluoro-phenyl)-methanone (1.83 g. 3.55 mmol) and N,N-diisopropylethylamine (2.5 mL, 14.22 mmol) in dry tetrahydrofuran (15 mL) was added to the reaction mixture. The mixture was stirred at room temperature overnight and then at 75° C. for 2 hours. The volatiles were evaporated and the residue taken up with dichloromethane and washed with brine. The organic phase was dried over sodium sulfate and evaporated to dryness. Purification of the crude by chromatography over silica gel (DCM/MeOH) afforded 2.51 g of the title compound as as yellow powder (92% yield).

Provenance & Evidence