Benzylhydrazine dihydrochloride → 1-benzyl-6-bromo-3-ethyl-1H-indazole

HRID 849316Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 849316
[Br:1][C:2]1[CH:3]=[CH:4][C:5]([C:13](=O)[CH2:14][CH3:15])=[C:6](OS(C)(=O)=O)[CH:7]=1.Cl.Cl.[CH2:19]([NH:26][NH2:27])[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1.C([O-])(=O)C.[Na+]>ClCCl>[Br:1][C:2]1[CH:7]=[C:6]2[C:5]([C:13]([CH2:14][CH3:15])=[N:27][N:26]2[CH2:19][C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=2)=[CH:4][CH:3]=1

Komponenten

5

Edukt 3

HCID 146540Benzylhydrazine dihydrochlorideHCID 517045Sodium AcetateHCID 109248095-Bromo-2-propionylphenyl methanesulfonate

Produkt 1

HCID 154293321-benzyl-6-bromo-3-ethyl-1H-indazoleAusbeute 41 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel

Reaktionsbedingungen

Temperatur
135 °C

Versuchsvorschrift

Methanesulfonic acid 5-bromo-2-propionyl-phenyl ester (5.00 g, 16.3 mmol) was combined with benzylhydrazine dihydrochloride (4.45 g, 22.8 mmol) and sodium acetate (4.01 g, 48.9 mmol) in xylenes (30 mL). The reaction mixture was heated to 135° C. for two days using a Dean Stark apparatus. The reaction was cooled to room temperature, diluted with dichloromethane (75 mL), and washed with water (75 mL) and 1N aqueous hydrochloric acid (75 mL). The organic extracts were dried over magnesium sulfate and concentrated. The crude product was purified by chromatography on silica gel eluting with 4:1 hexanes/ethyl acetate to yield 2.10 g of 6-bromo-1-benzyl-3ethyl-1H-indazole (41% yield). 1H NMR (400 MHz, CDCl3) δ 1.39 (t, 3, J=7.7), 2.96 (q, 2, J=7.7), 5.48 (s, 2), 7.14-7.23 (m, 3), 7.26-7.31 (m, 3), 7.42 (s, 1), 7.54 (d, 1, J=8.5). 13C NMR (100 MHz, CDCl3) δ 13.70, 20.37, 52.68, 112.12, 120.77, 121.69, 121.83, 123.34, 126.97, 127.76, 128.75, 136.74, 141.37, 147.60. IR 3064, 3031, 2970, 2934, 2875, 1606, 1504, 1497, 1454, 1236, 1048, 831, 701 cm1. Analysis calculated for C16H15BrN2 : C, 60.97; H, 4.80; N, 8.89. Found: C, 61.21; H, 4.92; N, 8.73.

Aufarbeitung

  1. temperatureThe reaction was cooled to room temperature
  2. washwashed with water (75 mL) and 1N aqueous hydrochloric acid (75 mL)
  3. dry with materialThe organic extracts were dried over magnesium sulfate
  4. concentrationconcentrated
  5. customThe crude product was purified by chromatography on silica gel eluting with 4:1 hexanes/ethyl acetate

Quellen und Nachweise

ORD-Eintrag
ord-8d1cc5c679d14e098b43a6296952c9a2
Quelldatensatz
uspto-grants-2000_01
Patentnummer
US06011159

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