Ammonium Chloride → 4-(5-fluoro-1H-indol-3-yl)-2-methyl-butan-2-ol

HRID 2382041Notes

Reaction equation

[F:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][CH:6]=[C:5]2[CH2:11][CH2:12][C:13](=[O:15])[CH3:14].[CH3:16][Mg+].[Br-].[NH4+].[Cl-]>C1COCC1>[F:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][CH:6]=[C:5]2[CH2:11][CH2:12][C:13]([CH3:16])([OH:15])[CH3:14]

Participants

Conditions

Temperature: 0 °C

Procedure

A solution of 4-(5-fluoro-1H-indol-3-yl)-butan-2-one (11.1 g, 54.1 mmol) in THF (200 mL) at 0° C. is treated with MeMgBr (54.1 mL, 3 M in THF, 162.3 mmol) and stirred at 0° C. for 2 h, and warmed to rt overnight. The mixture is then poured over ice, treated with solid NH4Cl (3 g), and extracted with EtOAc (3×120 mL). The combined organic layer is dried (Na2SO4), filtered and concentrated in vacuo. The residue is purified by silica gel chromatography eluting with 10%-60% EtOAc in heptane to afford 4-(5-fluoro-1H-indol-3-yl)-2-methyl-butan-2-ol (3.07 g, 26%). MS: 222 (M+H); 1H NMR (300 MHz, CDCl3): δ 7.94 (s, NH, 1H), 7.22 (m, 2H), 7.03 (s, 1H), 6.93 (m, 1H), 2.81 (m, 2H), 1.90 (m, 2H), 1.33 (s, 6H).

Workup

temperaturewarmed to rt overnight
additionThe mixture is then poured over ice
extractionextracted with EtOAc (3×120 mL)
dry with materialThe combined organic layer is dried (Na2SO4)
filtrationfiltered
concentrationconcentrated in vacuo
customThe residue is purified by silica gel chromatography
washeluting with 10%-60% EtOAc in heptane

Sources & evidence

ORD record: ord-7402002e2a7749bc9ccfeb4170820c99
Source dataset: uspto-grants-2012_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08258130B2

Reaction notes

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