Dichloromethane → (1S,4S)-2,5-Diazabicyclo[2.2.1]heptane-2-carboxamide hydrochloride

Participants

Reaction Steps

To a solution of (S,S)-2,5-diaza-bicyclo[2.2.1]heptane-2-carboxylic acid tert-butyl ester (35.6 g, 179 mmol) in CH2Cl2 (600 mL) was added trimethylsilylisocyanate (82.5 g, 716 mmol). After 2 h at rt, the mixture was concentrated, and the resulting white solid was dissolved in CH2Cl2 (500 mL). The solution was then treated with a solution of HCl (4.0 N in 1,4-dioxane, 135 mL). The resulting heterogeneous suspension was then stirred at rt overnight. Upon evaporation of the solvents, the desired product was isolated as a white solid (33 g), which was used directly in the next step. [Note: the mass balance was found to be 104%, which arose from additional HCl that could not be removed by standard evaporation under vacuum].

Provenance & Evidence