Tetrahydrofuran → 4-(2-Tert-butyl-4-nitrothiophene-5-carbonyl)-1-(2-(dimethylamino)ethyl)-3,3-dimethylpiperazin-2-one

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Reaction Steps

A stirred solution of 5-tert-butyl-3-nitrothiophene-2-carboxylic acid (0.214 g, 0.933 mmol) in 2 ml thionyl chloride was warmed at 45° C. for 1 h and then concentrated under vacuum. The residue was dissolved in 2 ml THF and added to a 3 ml THF solution of 1-(2-(dimethylamino)ethyl)-3,3-dimethylpiperazin-2-one (0.242 g, 1.21 mmol) and DIEA (0.362 g, 2.80 mmol). The resulting mixture was stirred at room temperature for 5 minutes, diluted with ethyl acetate, washed with 1N HCl, water, brine, dried and the solvent eliminated under vacuum to yield 0.300 g, (˜85% purity) of 4-(2-tert-butyl-4-nitrothiophene-5-carbonyl)-1-(2-(dimethylamino)ethyl)-3,3-dimethyl-piperazin-2-one that was used as-is for the next step.

Provenance & Evidence