Sodium Hydroxide → 4-[(Tert-butoxy)carbonyl]piperazine-2-carboxylic acid

Participants

Reaction Steps

To a solution of 2-piperazine-carboxylic acid dihydrochloride (1.0 g, 4.92 mmol) in 20 mL of water/dioxane 1:1, NaOH 6N was added to adjust the pH to 11. A solution of BOC-ON® (1.34 g, 5.41 mmol) in dioxane (5 mL) was then added dropwise, while maintaining the pH=11 during the addition and the resulting solution was stirred overnight at room temperature. Another 0.134 g of BOC-ON® were added and the reaction mixture was stirred for 2 h. The solvent was evaporated under reduced pressure and the residue was diluted with diethyl ether/water (60 mL). The phases were separated and the pH of the aqueous layer was adjusted to 7 by slow addition of HCl 1N. Evaporation of water under reduced pressure afforded the title compound as a white solid which was dried in a vacuum oven at 50° C. and used without further purification for the next step.

Provenance & Evidence