Triethylamine → (S)-N-(4-amino-3-nitrophenyl)-N-ethyl-1-methyl-pyrrolidine-2-carboxamide

Participants

Reaction Steps

Triethylamine (1.0 mL, 7.33 mmol) was added to a stirred solution of N1-ethyl-3-nitrobenzene-1,4-diamine (440 mg, 2.43 mmol), N-methyl-L-proline (314 mg, 2.43 mmol) and DEPBT (727 mg, 2.43 mmol) in acetonitrile (15 mL). The mixture was stirred at room temperature and further aliquots of N-methyl-L-proline (314 mg, 2.43 mmol), DEPBT (727 mg, 2.43 mmol), and triethylamine (1.0 mL, 7.33 mmol) were added after 1, 2, and 3 days. After stirring for a further 1 day, the mixture was concentrated and the residue taken up in EA (75 mL). The EA solution was extracted with water, and with 1M sodium carbonate solution (2×). The combined water and 1M sodium carbonate solution extracts were back-extracted with EA (4×) and the combined EA extracts washed with brine, dried over magnesium sulfate, and concentrated to give (S)—N-(4-amino-3-nitrophenyl)-N-ethyl-1-methyl-pyrrolidine-2-carboxamide (388 mg) as an orange/brown oil. This was hydrogenated in ethanol, using 10% palladium on carbon (153 mg) as the catalyst. After stirring overnight under a hydrogen atmosphere (balloon), the mixture was filtered through a pad of diatomaceous earth and the filtrate concentrated to give (S)—N-(3,4-diaminophenyl)-N-ethyl-1-methylpyrrolidine-2-carboxamide (335 mg).

Provenance & Evidence