Triethylamine → 1-benzyl 4-tert-butyl ((1S)-1-[(5-amino-1-methyl-1H-pyrazol-4-yl)carbamoyl]tetramethylene}biscarbamate

Participants

Reaction Steps

To a suspension of 1-methyl-1H-pyrazole-4,5-diamine sulfate (2.10 g), (2S)-2-[(benzyloxycarbonyl)amino]-5-[(tert-butoxycarbonyl)amino]pentanoic acid (3.66 g) and triethylamine (3.04 g) in chloroform (50 ml) was added N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (1.91 g), and the mixture was stirred at room temperature for 15 hours. The reaction mixture was washed successively with 10% aqueous citric acid solution, brine and saturated aqueous sodium hydrogencarbonate solution. The organic layer was dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give a crude product of 1-benzyl 4-tert-butyl {(1S)-1-[(5-amino-1-methyl-1H-pyrazol-4-yl)carbamoyl]tetramethylene}biscarbamate as an oil. The crude product was used directly in the next step without further purification.

Provenance & Evidence