Acetic Acid → 4-bromo-2-(4-bromophenyl)tetrahydro-2H-pyran

HRID 338542Notes

Reaction equation

HRID 338542 reaction equation
[Br:1][C:2]1[CH:9]=[CH:8][C:5]([CH:6]=[O:7])=[CH:4][CH:3]=1.[CH2:10](O)[CH2:11][CH:12]=[CH2:13].[BrH:15].C(O)(=O)C>ClCCl.[Br-].[Zn+2].[Br-]>[Br:15][CH:11]1[CH2:12][CH2:13][O:7][CH:6]([C:5]2[CH:8]=[CH:9][C:2]([Br:1])=[CH:3][CH:4]=2)[CH2:10]1

Participants

7

Reactant 4

HCID 176Acetic AcidHCID 260Hydrogen BromideHCID 693893-Buten-1-olHCID 707414-Bromobenzaldehyde

Product 1

HCID 696543814-bromo-2-(4-bromophenyl)tetrahydro-2H-pyranYield 57.8%

Reagents, catalysts & solvents 2

HCID 10421208Zinc bromideCatalystHCID 6344DichloromethaneSolvent

Procedure

To a solution of 4-bromobenzaldehyde (1.00 g, 5.41 mmol) and 3-buten-1-ol (800 mg, 10.8 mmol) in dichloromethane (20 mL) at room temperature was added zinc (II) bromide (25 mg, 0.11 mmol) followed by 33% hydrobromic acid (2.4 g) in acetic acid (4.9 g, 81 mmol) and stirred at room temperature for 5 hours. Reaction was quenched by aqueous sodium bicarbonate, then extracted with ethyl acetate, washed with brine, dried over sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography to give the title compound (1.00 g) which contained some of 4-bromobenzaldehyde 1H NMR (400 MHz, CDCl3) δ ppm 7.49 (d, 2H) 7.24 (d, 2H) 5.19 (dd, 1H) 4.25 (m, 1H) 4.12 (m, 1H) 3.60 (m, 1H) 2.75 (m, 1H) 2.68 (m, 1H) 2.11 (m, 2H).

Workup

  1. customReaction
  2. customwas quenched by aqueous sodium bicarbonate
  3. extractionextracted with ethyl acetate
  4. washwashed with brine
  5. dry with materialdried over sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe residue was purified by silica gel chromatography

Sources & evidence

ORD record
ord-72683094051c4703ae060802498a418c
Source dataset
uspto-grants-2014_11
Patent number
US08889730B2

Reaction notes

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