Water → Tert-butyl 4-(benzo[d][1,3]dioxol-4-yl)piperazine-1-carboxylate

HRID 1023211

Reaction equation

HRID 1023211 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[C:15]1[C:23]2[O:22][CH2:21][O:20][C:19]=2[CH:18]=[CH:17][CH:16]=1.C(=O)([O-])[O-].[Cs+].[Cs+].O>C1(C)C=CC=CC=1.C([O-])(=O)C.[Pd+2].C([O-])(=O)C.C1(P(C2C=CC=CC=2)C2C=CC3C(=CC=CC=3)C=2C2C3C(=CC=CC=3)C=CC=2P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[O:20]1[C:19]2[CH:18]=[CH:17][CH:16]=[C:15]([N:4]3[CH2:5][CH2:6][N:1]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:2][CH2:3]3)[C:23]=2[O:22][CH2:21]1

Participants

8

Reactant 4

HCID 962WaterHCID 10796Cesium carbonateHCID 143452tert-Butyl piperazine-1-carboxylateHCID 27761894-Bromo-1,3-benzodioxole

Product 1

HCID 68282758Tert-butyl 4-(benzo[d][1,3]dioxol-4-yl)piperazine-1-carboxylateYield 75.5%

Reagents, catalysts & solvents 3

HCID 167845palladium(II) acetateCatalystHCID 634876Binap, (A+-)-CatalystHCID 1140TolueneSolvent

Conditions

Temperature
100 °C

Procedure

Tert-butyl piperazine-1-carboxylate (1.11 g, 5.97 mmol) was added to a solution of 4-bromobenzo[d][1,3]dioxole (1 g, 4.97 mmol) in Toluene (15.0 ml). The resulting suspension was degassed using a stream of argon. Cesium carbonate (2.27 g, 558 μl, 6.96 mmol), racemic-2,2′-bis(diphenylphosphino)-1,1′-binaphtyl (232 mg, 373 μmol, Eq: 0.075) and Palladium (II) Acetate (55.8 mg, 249 μmol) were added to this mixture. The reaction was then heated at 100° C. over night. The reaction was cooled to rt, 40 ml of water was added and the mixture was extracted with Ethyl Acetate (2×80 ml). The organic layers were dried over MgSO4 and concentrated under vacuum. The crude material was purified by flash chromatography (silica gel, 50 g, 0% to 50% EtOAc in heptane). to yield tert-butyl 4-(benzo[d][1,3]dioxol-4-yl)piperazine-1-carboxylate as a white solid (1.15 g, 75%). MS (ISP) m/z=307.4 [(M+H)+].

Workup

  1. customThe resulting suspension was degassed
  2. temperatureThe reaction was cooled to rt
  3. extractionthe mixture was extracted with Ethyl Acetate (2×80 ml)
  4. dry with materialThe organic layers were dried over MgSO4
  5. concentrationconcentrated under vacuum
  6. customThe crude material was purified by flash chromatography (silica gel, 50 g, 0% to 50% EtOAc in heptane)

Sources & evidence

ORD record
ord-1b75482718694e318c46573820c0ba65
Source dataset
uspto-grants-2014_05
Patent number
US08722683B2

Linked notes

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