Reaction #7285

Reaction equation

2-[N-(t-butyloxycarbonyl)]amino-cyclohexanone

aniline

acetic acid

NaBH(OAc)3

→

cis-N-phenyl-N′-(t-butyloxycarbonyl)-cyclohexane-1,2-diamine

Yield 9.0%

Solvents

CH2Cl2

THF

Conditions

Workup

1. 1
   Otherovernight
2. 2
   Washwashed with saturated aqueous NaHCO3 (50 mL)
3. 3
   WashThe aqueous phase was washed with CH2Cl2 (2×25 mL)
4. 4
   Dryingthe combined organic extracts dried (Na2SO4)
5. 5
   Filtrationfiltered
6. 6
   Concentrationconcentrated under reduced pressure
7. 7
   OtherPurification and separation of the resultant brown oil by flash chromatography on silica gel (Hexanes/EtOAc, 9:1)

Procedure

To a solution of 2-[N-(t-butyloxycarbonyl)]amino-cyclohexanone (0.785 g, 3.69 mmol, aniline (0.68 mL, 7.46 mmol) and glacial acetic acid (0.22 mL) in THF (10 mL) was added NaBH(OAc)3 (1.173 g, 5.53 mmol) and the mixture was stirred at 60□ C. overnight. The reaction was cooled to room temperature, diluted with CH2Cl2 (60 mL) and washed with saturated aqueous NaHCO3 (50 mL). The aqueous phase was washed with CH2Cl2 (2×25 mL) and the combined organic extracts dried (Na2SO4), filtered and concentrated under reduced pressure. Purification and separation of the resultant brown oil by flash chromatography on silica gel (Hexanes/EtOAc, 9:1) afforded the low polarity cis-N-phenyl-N′-(t-butyloxycarbonyl)-cyclohexane-1,2-diamine isomer (0.095 g, 9%) and the high polarity trans-N-phenyl-N′-(t-butyloxycarbonyl)-cyclohexane-1,2-diamine isomer (0.412 g, 39%), both as pale yellow solids.

Source