Reaction #71631

Reaction equation

NaHCO3

4-bromobenzaldehyde

1,1-dimethylethyl (2R,6S)-2,6-dimethyl-1-piperazinecarboxylate

sodium triacetoxyborohydride

→

title compound

Yield 91.8%

1,1-Dimethylethyl (2R,6S)-4-[(4-bromophenyl)methyl]-2,6-dimethyl-1-piperazinecarboxylate

Yield 91.8%

Solvents

1,2-DCE

Conditions

Workup

1. 1
   workup.STIRRINGthe mixture stirred for 30 mins
2. 2
   ExtractionThe product was extracted into EtOAc
3. 3
   Dryingthe extracts dried (Na2SO4)
4. 4
   Concentrationconcentrated
5. 5
   workup.DISSOLUTIONThe residue was dissolved in DCM
6. 6
   workup.ADDITIONtreated with PS-hydrazine resin
7. 7
   workup.STIRRINGwith stirring for 2 h
8. 8
   OtherThe resin was removed by filtration
9. 9
   Otherthe solvent removed in vacuo

Procedure

A mixture of 4-bromobenzaldehyde (1.85 g, 10 mmol), 1,1-dimethylethyl (2R,6S)-2,6-dimethyl-1-piperazinecarboxylate (2.15 g, 10 mmol) and sodium triacetoxyborohydride (3.18 g) in 1,2-DCE (35 ml) was stirred at room temperature for 3 days. Saturated aq. NaHCO3 solution was added and the mixture stirred for 30 mins. The product was extracted into EtOAc and the extracts dried (Na2SO4) and concentrated. The residue was dissolved in DCM and treated with PS-hydrazine resin with stirring for 2 h. The resin was removed by filtration and the solvent removed in vacuo. Chromatography (0-40% EtOAc/hexane) gave the title compound (3.52 g). MS (ES): MH+ 383/385.

Source