5-bromo-7-(bromomethyl)-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-indazole → 5-Bromo-7-methyl-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazole

HRID 913799Notes

Reaction equation

HRID 913799 reaction equation
BrC1C=C2C(=C(CBr)C=1)N(COCC[Si](C)(C)C)N=C2.[Br:21][C:22]1[CH:30]=[C:29]([CH2:31]Br)[C:28]2[C:24](=[CH:25][N:26]([CH2:33][O:34][CH2:35][CH2:36][Si:37]([CH3:40])([CH3:39])[CH3:38])[N:27]=2)[CH:23]=1>>[Br:21][C:22]1[CH:30]=[C:29]([CH3:31])[C:28]2[C:24](=[CH:25][N:26]([CH2:33][O:34][CH2:35][CH2:36][Si:37]([CH3:38])([CH3:40])[CH3:39])[N:27]=2)[CH:23]=1

Participants

3

Reactant 2

HCID 575461635-bromo-7-(bromomethyl)-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-indazoleHCID 575462265-bromo-7-(bromomethyl)-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazole

Product 1

HCID 115809285-Bromo-7-methyl-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazole

Procedure

5-Bromo-7-(bromomethyl)-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-indazole and 5-Bromo-7-(bromomethyl)-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazole. A flask was charged with 5-bromo-7-methyl-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazole (2.0 g, 5.86 mmol), N-bromosuccinimide (1.04 g, 5.86 mmol), benzoic peroxyanhydride (0.043 g, 0.18 mmol), and carbon tetrachloride (12 mL). The reaction was heated at reflux overnight. The reaction was concentrated. The resulting residue was suspended in diethyl ether (10 mL). To this was added pentane (20 mL). After stirring for 5 min, the solid was removed by filtration and the mother liquor concentrated. The residue was purified by column chromatography (3%→8% EtOAc/Hex) to give 3 fractions. The fastest eluting fraction was concentrated to give 5-bromo-7-(bromomethyl)-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-indazole (0.95 g, 39%). The slowest eluting fraction was concentrated to give 5-bromo-7-(bromomethyl)-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazole (420 mg, 17%). 5-Bromo-7-(bromomethyl)-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-indazole: 1H-NMR (CDCl3, 500 MHz) δ 7.95 (s, 1H), 7.84 (d, J=1.5 Hz, 1H), 7.49 (d, J=1.5 Hz, 1H), 5.98 (s, 2H), 4.93 (s, 2H), 3.50 (t, J=8.2 Hz, 2H), 0.85 (t, J=8.2 Hz, 2H), <0.10 (s, 9H); 13C-NMR (CDCl3, 126 MHz) δ 136.2, 133.5, 132.0, 128.4, 124.6, 123.1, 114.1, 80.4, 66.4, 29.8, 17.9, −1.4. 5-Bromo-7-(bromomethyl)-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazole: 1H-NMR (CDCl3, 500 MHz) δ 8.07 (s, 1H), 7.79 (d, J=1.5 Hz, 1H), 7.41 (d, J=1.5 Hz, 1H), 5.72 (s, 2H), 4.84 (s, 2H), 3.64 (t, J=8.2 Hz, 2H), 0.93 (t, J=8.2 Hz, 2H), 0.00 (s, 9H); 13C-NMR (CDCl3, 126 MHz) δ 145.6, 130.2, 129.3, 123.8, 123.4, 122.8, 115.2, 82.1, 67.9, 28.2, 18.0, −1.3.

Sources & evidence

ORD record
ord-00957191f52a4c97a452e568f82cad79
Source dataset
uspto-grants-2011_09
Patent number
US08026257B2

Reaction notes

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