Diisopropylethylamine → Hydrogen Bromide

Participants

Reaction Steps

6-(Bromoacetyl)-3,4-dihydro-1H-isochromen-1-one (˜1.54 g, ˜5.72 mmol, presence of α-chloroketone was noted, ˜10%) and commercially available (S)-4-N-BOC-2-hydroxymethylpiperazine (1.24 g, 5.72 mmol) were added to a round bottom flask and diluted with THF (50 mL). Diisopropylethylamine (1.30 mL, 7.44 mmol) was then introduced and the mixture left stirring for 14 h at RT during which time a considerable amount of solid had formed (presumably HBr salt of DIPEA). The reaction mixture was diluted with EtOAc, then washed with saturated NH4Claq followed by H2O. Both aqueous layers were sequentially back extracted once with another portion of EtOAc, the organics were then combined, dried with MgSO4, filtered, and concentrated in vacuo. The recovered crude product was subjected to purification by flash chromatography (Biotage, 50% EtOAc/Hex) to afford the title compound.

Provenance & Evidence