Phenyltrimethylammonium bromide dibromide → 2-Bromo-1-(3,5,5-trimethyl-4,5,6,7-tetrahydro-benzo[c]thiophen-1-yl)-ethanone

HRID 2240815Notes

Reaction equation

HRID 2240815 reaction equation
[CH3:1][C:2]1[S:6][C:5]([C:7]([OH:9])=O)=[C:4]2[CH2:10][CH2:11][C:12]([CH3:15])([CH3:14])[CH2:13][C:3]=12.[Br-:16].[Br-].[Br-].[C:19]1([N+](C)(C)C)C=CC=CC=1.C1([N+](C)(C)C)C=CC=CC=1.C1([N+](C)(C)C)C=CC=CC=1>C1COCC1.CO>[Br:16][CH2:19][C:7]([C:5]1[S:6][C:2]([CH3:1])=[C:3]2[CH2:13][C:12]([CH3:15])([CH3:14])[CH2:11][CH2:10][C:4]=12)=[O:9]

Participants

5

Reactant 2

HCID 17977687Phenyltrimethylammonium bromide dibromideHCID 57508884HCID 57508884, compound

Product 1

HCID 575089072-Bromo-1-(3,5,5-trimethyl-4,5,6,7-tetrahydro-benzo[c]thiophen-1-yl)-ethanoneYield 80%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 1-(3,5,5-trimethyl-4,5,6,7-tetrahydro-benzo[c]thiophen-1-yl)-ethanone (1.18 g, 5.31 mmol, Example C) in THF (60 mL) and methanol (6 mL), phenyltrimethylammonium bromide dibromide (2.0 g, 5.31 mmol) is added in portions. Upon complete addition, the mixture is stirred at rt for 30 min before the solvent is evaporated. The crude product is purified by prep. HPLC (Grom-Sil 120 ODS-4-HE, 30×75 mm, 10 μm, 20-95% acetonitrile in water containing 0.5% formic acid) to give 2-bromo-1-(3,5,5-trimethyl-4,5,6,7-tetrahydro-benzo[c]thiophen-1-yl)-ethanone (1.28 g) as a colourless oil; 1H NMR (CDCl3): δ 4.24 (s, 2H), 3.03 (t, J=7.0 Hz, 2H), 2.36 (s, 3H), 2.30 (s, 2H), 1.54 (t, J=7.0 Hz, 2H), 0.98 (s, 6H).

Workup

  1. additionUpon complete addition
  2. customis evaporated
  3. customThe crude product is purified by prep

Sources & evidence

ORD record
ord-41709029bdde4892978f9ef2c467dc7d
Source dataset
uspto-grants-2010_05
Patent number
US07723378B2

Reaction notes

Loading…