Bromobenzene → tert-Butyl 4-phenylpiperazine-1-carboxylate

HRID 1405442Notes

Reaction equation

HRID 1405442 reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[N:8]1([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]1.C1C=CC(P(C2C(C3C(P(C4C=CC=CC=4)C4C=CC=CC=4)=CC=C4C=3C=CC=C4)=C3C(C=CC=C3)=CC=2)C2C=CC=CC=2)=CC=1.CC([O-])(C)C.[Na+]>C1(C)C=CC=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd]>[C:2]1([N:11]2[CH2:10][CH2:9][N:8]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:13][CH2:12]2)[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

7

Reactant 4

HCID 7961BromobenzeneHCID 143452tert-Butyl piperazine-1-carboxylateHCID 634876Binap, (A+-)-HCID 23676156Sodium t-butoxide

Product 1

HCID 15316568tert-Butyl 4-phenylpiperazine-1-carboxylateYield 78%

Reagents, catalysts & solvents 2

HCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 1140TolueneSolvent

Conditions

Temperature
100 °C

Procedure

A solution of 1-bromobenzene (1 g, 6.37 mmol, 1.00 equiv), t-butyl piperazine-1-carboxylate (2.35 g, 12.62 mmol, 2.00 equiv), BINAP (196 mg, 0.63 mmol, 0.10 equiv), Pd2(dba)3 (290 mg, 0.32 mmol, 0.05 equiv), and NaOt-Bu (1.89 g, 18.90 mmol, 3.00 equiv) in toluene (20 mL) was placed in a 100-mL 3-necked round bottom flask and stirred overnight at 100° C. in an oil bath under an inert atmosphere. The resulting mixture was concentrated under vacuum and purified via silica gel column (ethyl acetate/petroleum ether (1:40)) yielding 1.3 g (78%) of t-butyl 4-phenylpiperazine-1-carboxylate as a yellow solid.

Workup

  1. concentrationThe resulting mixture was concentrated under vacuum
  2. custompurified via silica gel column (ethyl acetate/petroleum ether (1:40))

Sources & evidence

ORD record
ord-e1e579794d9c47fc969e7059357e7193
Source dataset
uspto-grants-2014_12
Patent number
US08916560B2

Reaction notes

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