Triethylamine → Tert-butyl 4-[(4-bromo-2-methylphenyl)methyl]piperazine-1-carboxylate

HRID 2278261Notes

Reaction equation

HRID 2278261 reaction equation
[N:1]1([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.[Br:14][C:15]1[CH:22]=[CH:21][C:18]([CH:19]=O)=[C:17]([CH3:23])[CH:16]=1.C(N(CC)CC)C.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>O.ClCCl>[Br:14][C:15]1[CH:22]=[CH:21][C:18]([CH2:19][N:4]2[CH2:5][CH2:6][N:1]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:2][CH2:3]2)=[C:17]([CH3:23])[CH:16]=1

Participants

7

Reactant 4

HCID 8471TriethylamineHCID 143452tert-Butyl piperazine-1-carboxylateHCID 5049666Sodium triacetoxyborohydrideHCID 135551504-Bromo-2-methylbenzaldehyde

Product 1

HCID 89676989Tert-butyl 4-[(4-bromo-2-methylphenyl)methyl]piperazine-1-carboxylateYield 102.9%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

A 250 mL round-bottom flask was charged with tert-butyl piperazine-1-carboxylate (2.80 g, 15.0 mmol, 1.00 equiv), 4-bromo-2-methylbenzaldehyde (3.28 g, 16.5 mmol, 1.10 equiv), dichloromethane (80 mL). Triethylamine (4.56 g, 45.1 mmol, 3.00 equiv) was added. The resulting solution was stirred for 30 mins at room temperature. Sodium triacetoxyborohydride (9.60 g, 45.3 mmol, 3.00 equiv) was added. The resulting solution was stirred overnight at room temperature and then diluted with water (100 mL). The resulting solution was extracted with dichloromethane (3×60 mL) and the organic layers were combined, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (20/80) to provide 5.70 g (98% yield) of tert-butyl 4-[(4-bromo-2-methylphenyl)methyl]piperazine-1-carboxylate as light yellow oil. LCMS (ESI, m/z): 369 [M+H]+.

Workup

  1. stirringThe resulting solution was stirred overnight at room temperature
  2. extractionThe resulting solution was extracted with dichloromethane (3×60 mL)
  3. dry with materialdried over Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated under reduced pressure
  6. customThe residue was chromatographed on a silica gel column with ethyl acetate/petroleum ether (20/80)

Sources & evidence

ORD record
ord-bf5622b52b7a4950b02686270f200ae2
Source dataset
uspto-grants-2015_09
Patent number
US09133148B2

Reaction notes

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