Hydrogen Bromide → 2,3-Dihydro-1-benzofuran-4-amine

HRID 2252742Notes

Reaction equation

HRID 2252742 reaction equation
OC[CH2:3][C:4]1[C:17]([O:18][CH3:19])=[CH:16][CH:15]=[CH:14][C:5]=1[NH:6]C(OC(C)(C)C)=O.Br.[OH-].[Na+]>C(O)(=O)C>[O:18]1[C:17]2=[CH:16][CH:15]=[CH:14][C:5]([NH2:6])=[C:4]2[CH2:3][CH2:19]1

Participants

5

Reactant 3

HCID 260Hydrogen BromideHCID 14798Sodium HydroxideHCID 22282726tert-butyl N-[2-(2-hydroxyethyl)-3-methoxyphenyl]carbamate

Product 1

HCID 117010432,3-Dihydro-1-benzofuran-4-amineYield 97.8%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

2-(2′-Hydroxyethyl)-3-methoxy-N-tert-butoxycarbonyl-aniline (158 g, 0.59 mol) was added portionwise to a stirred solution of hydrogen bromide in acetic acid (30%, 1.7 L) at room temperature. The reaction was then heated to reflux for 4 h. The reaction mixture was cooled to room temperature, basified to pH 14 with aqueous sodium hydroxide solution (6 N) and extracted with dichloromethane (3×2 L). The organic extracts were combined, dried (magnesium sulphate) and evaporated to give the title compound as an orange oil (78 g, 92%); NMR (400 MHz, CDCl3) δH 2.99 (2H, t, J 8.5 Hz), 3.55 (2H, br s), 4.57 (2H, t, J 8.5 Hz), 6.19 (1H, d, J 7.5 Hz), 6.25 (2H, d, J 7.5 Hz), 6.92 (1H, t, J 8.0 Hz); IR νmax (Nujol)/cm−1 2853, 2610, 1544, 1462, 1262, 1234, 986 and 761.

Workup

  1. temperatureThe reaction was then heated
  2. temperatureto reflux for 4 h
  3. extractionextracted with dichloromethane (3×2 L)
  4. dry with materialdried (magnesium sulphate)
  5. customevaporated

Sources & evidence

ORD record
ord-5736cc709cd647b1b16293eeb22da43c
Source dataset
uspto-grants-2008_01
Patent number
US07323473B2

Reaction notes

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