Cyanogen Bromide → (S)-tert-butyl 5-[(3,5-bistrifluoromethylbenzyl)cyanoamino]-7-methyl-8-trifluoromethyl-2,3,4,5-tetrahydrobenzo[b]azepine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Add cyanogen bromide (1.21 mL, 6.04 mmol, 5 M solution in acetonitrile) to a solution of (S)-tert-butyl 5-(3,5-bistrifluoromethylbenzylamino)-7-methyl-8-trifluoromethyl-2,3,4,5-tetrahydrobenzo[b]azepine-1-carboxylate (2.30 g, 4.03 mmol) and diisopropylethylamine (1.05 mL, 6.04 mmol) in tetrahydrofuran (50 mL) at room temperature under nitrogen and heat the mixture at 50° C. for 12 h. Add silica gel to the cooled mixture and remove the solvents under reduced pressure. Purify the residue by column chromatography on silica gel, eluting with ethyl acetate/hexanes (2:3), to provide the title compound as a colorless oil (2.10 g, >99%), which is used in the next step without further purification: APCI MS m/z 496 (M+H−Boc)+.

Provenance & Evidence