5-Bromothiophene-2-carbaldehyde → 5-PIPERAZIN-1-YLTHIOPHENE-2-CARBALDEHYDE

Participants

Reaction Steps

A suspension of 1.09 g (5.7 mmol) of 5-bromothiophene-2-carboxaldehyde and 3.19 g (17.1 mmol) of tert-butyl piperazine-1-carboxylate in 30 ml of water is heated under reflux for 48 h. The aqueous phase is extracted three times with methylene chloride. The organic phases are combined, dried over sodium sulfate, filtered, and evaporated. The residue is purified by chromatography on silica (MeOH gradient in dichloromethane: 5 to 10%) to yield 0.80 g (70%) of 5-(piperazin-1-yl)thiophene-2-carboxaldehyde in the form of a blue-grey solid.

Provenance & Evidence