N-bromobutanimide → Methyl 12-bromo-11-dodecynoate

Participants

Reaction Steps

To a mechanically stirred solution of ester 4 (37 g, 176 mmol) in 700 mL of acetone under nitrogen was added N-bromosuccinimide (34.4 g, 194 mmol) followed by silver nitrate (2.7 g, 18 mmol). The reaction mixture was allowed to stir at room temperature in the absence of light for 21 h. The thick, pale yellow reaction mixture was filtered through a sintered glass funnel, concentrated in vacuo to one third volume, and diluted with 500 mL of water. This was extracted with 4×250 mL of hexanes, and the combined organic layers were washed with 100 mL of brine, dried over sodium sulfate, concentrated in vacuo, and vacuum dried to give bromoacetylene 5 (47.81 g, 94%) as a yellow oil:

Provenance & Evidence