Potassium Carbonate → 4-(2,6-Dinitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester

HRID 33594

Reaktionsgleichung

Reaktionsgleichung von HRID 33594
Cl[C:2]1[C:7]([N+:8]([O-:10])=[O:9])=[CH:6][CH:5]=[CH:4][C:3]=1[N+:11]([O-:13])=[O:12].[C:14]([O:18][C:19]([N:21]1[CH2:26][CH2:25][NH:24][CH2:23][CH2:22]1)=[O:20])([CH3:17])([CH3:16])[CH3:15].C([O-])([O-])=O.[K+].[K+]>C(#N)C>[C:14]([O:18][C:19]([N:21]1[CH2:26][CH2:25][N:24]([C:2]2[C:7]([N+:8]([O-:10])=[O:9])=[CH:6][CH:5]=[CH:4][C:3]=2[N+:11]([O-:13])=[O:12])[CH2:23][CH2:22]1)=[O:20])([CH3:17])([CH3:15])[CH3:16]

Komponenten

5

Edukt 3

HCID 11430Potassium CarbonateHCID 118141-Chloro-2,6-dinitrobenzeneHCID 143452tert-Butyl piperazine-1-carboxylate

Produkt 1

HCID 865848194-(2,6-Dinitro-phenyl)-piperazine-1-carboxylic acid tert-butyl esterAusbeute 85 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6342AcetonitrileLösungsmittel

Versuchsvorschrift

To a stirred solution of 1.01 g (5.0 mmol) of 1-chloro-2,6-dinitrobenzene and 0.93 g (5.0 mmol) of 1-tert-butyloxycarbonylpiperazine in acetonitrile (5 mL) was added 1.38 g (10 mmol) of K2CO3. The mixture was heated to reflux for 48 h. The solvent was removed under reduced pressure. The crude product was partitioned between EtOAc (100 mL) and 20 mL of H2O. The organic layer was washed with H2O (2×20 mL), dried over Na2SO4 and concentrated. Column chromatography (silica, 10-20% EtOAc/hexanes) provided 1.31 g (85%) of 4-(2,6-dinitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester TLC (silica, 20% EtOAc/hexanes): Rf=0.35. 1H NMR (400 MHz, CDCl3): 7.75 (d, J=8.2 Hz, 2H), 7.25 (t, J=8.2 Hz, 1H), 3.30 (m, 4H), 2.95 (m, 2H), 1.44 (s, 9H). B. 1-[4-(2,6-Dinitro-phenyl)-piperazin-1-yl]-3-[5-methanesulfonyl-3-(4-trifluoromethyl-phenyl)-4,5,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-1-yl]-propan-2-ol. 4-(2,6-Dinitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (220 mg, 0.63 mmol) was dissolved in 5.0 mL of CH2Cl2 and treated with 3.0 mL of trifluoroacetic acid. The reaction mixture was stirred at 25° C. for 1 h before all volatiles were removed. The solid was treated with CH2Cl2 (20 mL) and aqueous KOH (4 N, 10 mL). The organic layer was separated, dried over Na2SO4, and concentrated. The crude oil (67 mg) was dissolved in absolute EtOH (1.2 mL) and treated with 141 mg (0.35 mmol, 1.3 eq) of 5-methanesulfonyl-1-oxiranylmethyl-3-(4-trifluoromethyl-phenyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine. The reaction mixture was refluxed at 85° C. for 3 h and then the solvent was removed. Column chromatography purification (silica, 10-20% acetone/CH2Cl2) provided 150 mg (85%) of 1-[4-(2,6-dinitro-phenyl)-piperazin-1-yl]-3-[5-methanesulfonyl-3-(4-trifluoromethyl-phenyl)-4,5,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-1-yl]-propan-2-ol. TLC (silica, 10% acetone/CH2Cl2): Rf=0.3. MS (electrospray): exact mass calculated for C27H30F3N7O7S, 653.19; m/z found, 654.2 [M+H]+. 1H NMR (400 MHz, CDCl3): 7.71 (d, J=8.2 Hz, 2H), 7.64 and 7.58 (AB pattern, J=8.4 Hz, 4H), 7.20 (t, J=8.2 Hz, 1H), 4.54 (s, 2H), 4.29-4.12 (m, 2H), 3.66 (t, J=5.3 Hz, 2H), 3.70-2.95 (m, 9H), 2.91 (s, 3H), 2.67-2.32 (m, 4H).

Aufarbeitung

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 48 h
  3. customThe solvent was removed under reduced pressure
  4. customThe crude product was partitioned between EtOAc (100 mL) and 20 mL of H2O
  5. washThe organic layer was washed with H2O (2×20 mL)
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated

Quellen und Nachweise

ORD-Eintrag
ord-f0c8b03e655d4719bea7263876e58dfe
Quelldatensatz
uspto-grants-2008_09
Patentnummer
US07429591B2

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