Pyrrolidine → 6-bromo-2-(tetrahydro-2H-pyran-3-yl)chroman-4-one

HRID 1770888Notes

Reaction equation

HRID 1770888 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]([OH:11])=[C:6]([C:8](=[O:10])[CH3:9])[CH:7]=1.[O:12]1[CH2:17][CH2:16][CH2:15][CH:14]([CH:18]=O)[CH2:13]1.N1CCCC1>CO>[Br:1][C:2]1[CH:7]=[C:6]2[C:5](=[CH:4][CH:3]=1)[O:11][CH:18]([CH:14]1[CH2:15][CH2:16][CH2:17][O:12][CH2:13]1)[CH2:9][C:8]2=[O:10]

Participants

5

Reactant 3

HCID 31268PyrrolidineHCID 959915'-Bromo-2'-hydroxyacetophenoneHCID 10129928Oxane-3-carbaldehyde

Product 1

HCID 584241476-bromo-2-(tetrahydro-2H-pyran-3-yl)chroman-4-oneYield 69.1%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 1-(5-bromo-2-hydroxyphenyl)ethanone (18 g, 83.70 mmol), tetrahydro-2H-pyran-3-carbaldehyde (9.55 g, 83.70 mmol) and pyrrolidine (6.95 mL, 83.70 mmol) in MeOH (125 mL) was heated to reflux for 4.5 h. The mixture was allowed to reach r.t. and concentrated. The residue was dissolved in EtOAc (150 mL) and washed with 1M NaOH (80 mL), 1M HCl (80 mL), and brine (80 mL) successively. The organic phase was concentrated, the residue was purified by flash chromatography with a gradient of 10% EtOAc in heptane to 40% EtOAc in heptane to give the title compound (18 g, 69% yield): 1H NMR (500 MHz, DMSO-d6) δ ppm 1.50 (m, 3H), 1.79 (m, 0.5H), 1.94 (m, 1.5H), 2.67 (m, 1H), 2.86 (m, 1H), 3.30 (m, 2H), 3.78 (m, 1H), 3.84 (m, 0.5H), 4.04 (dd, 0.5H), 4.44 (m, 1H), 7.05 (dd, 1H), 7.71 (m, 1H), 7.79 (d, 1H); MS (ES+) m/z 311 [M+H]+.

Workup

  1. temperatureto reflux for 4.5 h
  2. customto reach r.t.
  3. concentrationconcentrated
  4. dissolutionThe residue was dissolved in EtOAc (150 mL)
  5. washwashed with 1M NaOH (80 mL), 1M HCl (80 mL), and brine (80 mL) successively
  6. concentrationThe organic phase was concentrated
  7. customthe residue was purified by flash chromatography with a gradient of 10% EtOAc in heptane to 40% EtOAc in heptane

Sources & evidence

ORD record
ord-d5726b7d838f43a8b3daef4e54a12182
Source dataset
uspto-grants-2016_02
Patent number
US09248129B2

Reaction notes

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