Cesium carbonate → Ethyl 5-(3,4-dimethylpiperazin-1-yl)thiophene-2-carboxylate

HRID 1092068

Reaktionsgleichung

Reaktionsgleichung von HRID 1092068
Br[C:2]1[S:6][C:5]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:4][CH:3]=1.[CH3:12][N:13]1[CH2:18][CH2:17][NH:16][CH2:15][CH:14]1[CH3:19].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.C(=O)([O-])[O-].[Cs+].[Cs+]>C1(C)C=CC=CC=1.C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[CH3:19][CH:14]1[N:13]([CH3:12])[CH2:18][CH2:17][N:16]([C:2]2[S:6][C:5]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:4][CH:3]=2)[CH2:15]1

Komponenten

7

Edukt 4

HCID 10796Cesium carbonateHCID 198037DimethylpiperazineHCID 605723Ethyl 5-bromothiophene-2-carboxylateHCID 634876Binap, (A+-)-

Produkt 1

HCID 57440412Ethyl 5-(3,4-dimethylpiperazin-1-yl)thiophene-2-carboxylateAusbeute 47,7 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 167845palladium(II) acetateKatalysatorHCID 1140TolueneLösungsmittel

Reaktionsbedingungen

Temperatur
110 °C

Versuchsvorschrift

Palladium(II) acetate (0.112 g, 0.50 mmol) was added to a mixture of ethyl 5-bromothiophene-2-carboxylate (0.571 g, 5 mmol), 1,2-dimethyl-piperazine (1.175 g, 5 mmol), rac-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (0.311 g, 0.50 mmol) and cesium carbonate (2.281 g, 7.00 mmol) in toluene (50.0 ml) at 20° C. under nitrogen. The resulting suspension was stirred at 110° C. for 23 h. The crude product was purified by ion exchange chromatography, using a SCX2 column. The crude material was dissolved in methanol and then applied to the column. The desired product was eluted from the column using 2M NH3 in methanol and pure fractions were evaporated to dryness to afford the crude product as a brown oil. This material was further purified by silica column chromatography, eluting with a gradient of 1 to 5% MeOH in DCM. Pure fractions were evaporated to dryness to afford ethyl 5-(3,4-dimethylpiperazin-1-yl)thiophene-2-carboxylate (0.640 g, 47.7%) as a light brown solid.

Aufarbeitung

  1. customThe crude product was purified by ion exchange chromatography
  2. dissolutionThe crude material was dissolved in methanol
  3. washThe desired product was eluted from the column
  4. customwere evaporated to dryness
  5. customto afford the crude product as a brown oil
  6. customThis material was further purified by silica column chromatography
  7. washeluting with a gradient of 1 to 5% MeOH in DCM
  8. customPure fractions were evaporated to dryness

Quellen und Nachweise

ORD-Eintrag
ord-60983b7f5cf940db83db7a6851f5e5a3
Quelldatensatz
uspto-grants-2012_03
Patentnummer
US08129391B2

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