4-Bromophenyl isocyanate → N-(4-bromophenyl)-2-{[(3S)-1-(cyclopropylcarbonyl)-3-pyrrolidinyl]acetyl}hydrazinecarboxamide

Participants

Reaction Steps

In a round bottom flask under nitrogen, a solution of 2-[(3S)-1-(cyclopropylcarbonyl)-3-pyrrolidinyl]acetohydrazide (52.6 g, 249 mmol) in dichloromethane (356 mL) was cooled to 0° C. and 4-bromophenylisocyanate (49.3 g, 249 mmol) was added. Once the isocyanate dissolved, the cooling bath was removed and the reaction was allowed to warm to room temperature and was stirred for 27 h. White precipitate formed quickly. The reaction was filtered to collect the white precipitate, washed with 50 mL cold dichloromethane, and air dried. The white solid was washed with additional cold dichloromethane (300 mL) and dried under vacuum suction overnight to provide the title compound (108.29 g, 63% pure, 167 mmol, 67% yield). MS(ES)+ m/e 409.2, 411.2 [M+H]+.

Provenance & Evidence