Triethylamine → 2-[4-(4-Bromo-phenyl)piperazine-1-sulfonylmethyl]3-methylbutyric acid tert-butyl ester

Beteiligte Stoffe

Reaktionsschritte

A stirred suspension of 4-bromophenylpiperazine hydrochloride (2.84 g) and 2-chlorosulfonylmethyl-3-methyl-butyric acid tert-butyl ester (2.77 g) [preparation described in WO-A-98/05635] in dichloromethane (50 ml), cooled in an ice-bath, was treated with triethylamine (2 99 ml). The reaction was then stirred at room temperature for 2 h. The reaction mixture was then evaporated in vacuo, and the residue was dissolved in ethyl acetate (75 ml) and washed with 1% aqueous citric acid (2×50 ml), water (50 ml), saturated sodium bicarbonate (50 ml), saturated brine (50 ml), dried (MgSO4) and concentrated in vacuo to provide the title compound as a pale yellow gum (3.81 g, 79%).

Herkunft & Nachweise