To a stirred solution of sodium azide (5.63 g, 86.62 mmol) in 17 mL of water was added in a dropwise fashion to a solution of racemic 2-phenyl-3-(toluene-4-sulfonyl)-3-aza-bicyclo[3.1.0]hexane-1-carbonyl chloride (5.0 g, 13.3 mmol) (Intermediate 3) in 30 mL of acetone. 3 mL of water was then added to the reaction and the reaction mixture was stirred for 16 hours. The acetone was removed at reduced pressure and the reaction diluted with both methylene chloride and brine. The organic layer was separated, dried over sodium sulfate, filtered, and concentrated under reduced pressure to give 2-phenyl-3-(toluene-4-sulfonyl)-3-aza-bicyclo[3.1.0]hexane-1-carbonyl azide (5.1 g, 100% crude yield).
