Acetic Acid → tert-Butyl 4-cyclopropylpiperazine-1-carboxylate
Reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].C(O[C:17]1(O[Si](C)(C)C)[CH2:19][CH2:18]1)C.C(O)(=O)C.C([BH3-])#N.[Na+]>C1COCC1.CO>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([CH:17]2[CH2:19][CH2:18]2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]Participants
7
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 63 °C
Procedure
To a solution of 1-tert-butyloxycarbonylpiperazine (1.16 g, 6.23 mmol) in THF (10 ml) and methanol (5 ml) were added 1-ethoxy-1-trimethylsilyloxycyclopropane (2.40 ml, 12.0 mmol), acetic acid (0.75 ml), and sodium cyanoborohydride (7.8 ml of a 1M solution in THF, 7.8 mmol), and the mixture was stirred at 63° C. for 16 hours. The mixture was concentrated under reduced pressure, and the residue was mixed with water (20 ml) and potassium carbonate (6.6 g). The product was extracted with ethyl acetate (3×30 ml), the combined extracts were dried over magnesium sulphate, and concentrated under reduced pressure. 1.79 g (100%) of the title compound was obtained as an oil, which completely crystallized after a few hours.
Workup
- concentrationThe mixture was concentrated under reduced pressure
- additionthe residue was mixed with water (20 ml) and potassium carbonate (6.6 g)
- extractionThe product was extracted with ethyl acetate (3×30 ml)
- dry with materialthe combined extracts were dried over magnesium sulphate
- concentrationconcentrated under reduced pressure
Sources & evidence
- ORD record
- ord-58f0c5cc083d43e4ab86a819a00e10a9
- Source dataset
- uspto-grants-2007_04
- Patent number
- US07208497B2
Reaction notes
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