Hydrochloric Acid → 1-Cyclobutyl-[1,4]diazepane

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of tert-butyl 4-cyclobutyl-1,4-diazepane-1-carboxylate (6.1 g, 23.98 mmol) in DCM (70 ml) at 20 to 25° C. was added a solution of 4M HCl in dioxane (30 ml, 120 mmol) dropwise. The resulting mixture was stirred at 20 to 25° C. for ca. 2 h. MeOH (6 ml) was added and the resulting mixture stirred at 20 to 25° C. for 1 to 2 days. The solvent was removed at reduced pressure and the resulting gummy residue slurried in ether (100 ml) for 0.5 h. The solvent was evaporated and the residue slurried in ether/MeOH (10:1, 66 ml). The resulting white solid was collected by filtration, suspended in DCM (150 ml) and treated with 2M NaOH. The aqueous phase was extracted with DCM until complete transfer of product in the organic layer, as monitored by TLC analysis (eluent, DCM/MeOH/conc.NH3 (90:10:1); stain, PMA) was achieved. The combined organic phases were dried (Na2SO4), filtered and concentrated at reduced pressure to provide the title compound (2.67 g, 73% yield) as orange oil.

Provenance & Evidence