Potassium Carbonate → HCID 68465699, compound

Participants

Reaction Steps

8 g of 4-(2,5-difluoro-4-nitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (23 mmol) and 3.82 g potassium carbonate (27.65 mmol) were suspended in 80 ml DMF under stirring and then treated dropwise within 10 min with a solution of 5.29 g of 4-trifluoromethoxy-benzylamine (27.65 mmol) in 30 ml DMF. The reaction mixture was then stirred for 48 h at rt, diluted with 500 ml dichloromethane and 1 liter of water. After separation, the organic phase was washed with brine (500 ml). The two aqueous phases were then reextracted with 2×250 ml dichloromethane. The combined organic phases were dried over magnesium sulfate, filtered and concentrated in vacuo. The solid residue was stirred with 150 ml heptane/ethylacetate 4:1. After 10 minutes the suspension was diluted with 100 ml heptane, and after additional 10 min stirring, filtered. After drying in vacuo, 9.5 g of 4-[2-fluoro-4-nitro-5-(4-trifluoromethoxy-benzylamino)-phenyl]-piperazine-1-carboxylic acid tert-butyl ester was obtained as a yellow solid (80%). MS(ISP): 515.3 (M+H)+.

Provenance & Evidence