tert-Butanol → (S)-1-Boc-3-isopropylpiperazine

Participants

Reaction Conditions

Reaction Steps

5.68 ml (14.20 mmol, 1.00 eq.) of a 2.5 N aq. NaOH-solution were added to a solution of 1.82 g (14.19 mmol) 2-(S)-Isopropyl-piperazine (82) in 70 ml tert-Butanol and 70 ml H2O. After cooling to 0° C. 3.10 g (14.20 mmol, 1.00 eq.) Boc-anhydride was added and the mixture was stirred at 0° C. for 1 h. Then the solution was warmed to r.t. and stirred overnight. After evaporating the tert-Butanol the mixture was extracted with CH2Cl2. The comb. org. fractions were dried over Na2SO4 and evaporated. Column chromatography (CH2Cl2/MeOH (10+1)) yielded 3.19 g (13.96 mmol, 98.37%) 3-(S)-Isopropyl-piperazine-1-carboxylic acid tert-butyl ester (85) as a clear oil.

Provenance & Evidence