Carbon tetrabromide → N-(4-Chloro-2-iodo-phenyl)-N-(4-azido-2-methylene-butyl)-methanesulfonamide

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of N-(4-Chloro-2-iodo-phenyl)-N-(4-hydroxy-2-methylene-butyl)-methanesulfonamide obtained in Step A and triphenylphosphine (3.5 g) in dimethylacetamide (80 ml) at −10° C. under argon was added carbon tetrabromide (4.5 g). The reaction mixture was stirred at −10° C. for 45 min (a precipitate formed). Sodium azide (2 g) was added in one portion and the reaction mixture was stirred at 45° C. for 1 hour, cooled to room temperature, poured into water, extracted with ethyl acetate; the organic layer was washed with brine, dried (Na2SO4) and concentrated in vacuo. The residue was purified by silica gel chromatography (eluent cyclohexane:ethyl acetate 7:3) to afford N-(4-Chloro-2-iodo-phenyl)-N-(4-azido-2-methylene-butyl)-methanesulfonamide (1.96 g). 1H NMR (CDCl3, 400 MHz) 2.50 (m, 2H), 3.48 (m, 2H), 4.19 (d, J=12.0 Hz, 1H), 4.40 (d, J=12.0 Hz, 1H), 4.90 (s, 1H), 5.01 (s, 1H), 7.29 (d, J=8.5 Hz, 1H), 7.36 (dd, J=0.9H, 8.5 Hz, 1H), 7.92 (d, J=0.9 Hz, 1H).

Provenance & Evidence