tert-Butyl piperazine-1-carboxylate → t-Butyl 4-((3-methylbenzo[b]thiophen-2-yl)methyl)piperazine-1-carboxylate

HRID 639462Notes

Reaction equation

HRID 639462 reaction equation
[CH3:1][C:2]1[C:3]2[CH:12]=[CH:11][CH:10]=[CH:9][C:4]=2[S:5][C:6]=1[CH:7]=O.[N:13]1([C:19]([O:21][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:20])[CH2:18][CH2:17][NH:16][CH2:15][CH2:14]1.[BH-](OC(C)=O)(OC(C)=O)OC(C)=O.[Na+]>C(Cl)Cl>[CH3:1][C:2]1[C:3]2[CH:12]=[CH:11][CH:10]=[CH:9][C:4]=2[S:5][C:6]=1[CH2:7][N:16]1[CH2:15][CH2:14][N:13]([C:19]([O:21][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:20])[CH2:18][CH2:17]1

Participants

5

Reactant 3

HCID 143452tert-Butyl piperazine-1-carboxylateHCID 5199183-Methylbenzo(b)thiophene-2-carboxaldehydeHCID 5049666Sodium triacetoxyborohydride

Product 1

HCID 68415560t-Butyl 4-((3-methylbenzo[b]thiophen-2-yl)methyl)piperazine-1-carboxylate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 3-methylbenzo[b]thiophene-2-carbaldehyde (0.029 mol) in dry DCM (100 mL) is added t-butyl piperazine-1-carboxylate (0.0319 mol), and the mixture is stirred at RT for 1 h. 0.042 Mol of NaBH(OAc)3 is added in portions, and the reaction mixture is stirred overnight at RT. The resulting solution is concentrated under vacuum, and the residue is partitioned between DCM and aqueous sodium bicarbonate solution. The organic phase is separated, washed with water, dried (MgSO4) and evaporated in vacuo. The residue is purified by column chromatography on silica gel by eluting with DCM/MeOH (9/1) to afford t-butyl 4-((3-methylbenzo[b]thiophen-2-yl)methyl)piperazine-1-carboxylate.

Workup

  1. stirringthe reaction mixture is stirred overnight at RT
  2. concentrationThe resulting solution is concentrated under vacuum
  3. customthe residue is partitioned between DCM and aqueous sodium bicarbonate solution
  4. customThe organic phase is separated
  5. washwashed with water
  6. dry with materialdried (MgSO4)
  7. customevaporated in vacuo
  8. customThe residue is purified by column chromatography on silica gel
  9. washby eluting with DCM/MeOH (9/1)

Sources & evidence

ORD record
ord-16e158e984bf457399a66c91021cbc4f
Source dataset
uspto-grants-2010_04
Patent number
US07691869B2

Reaction notes

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