3,4-dihydro-2H-pyran → 4,5-dibromo-2-{4-[(tetrahydropyranyl)oxy]phenyl}-2H-pyridazin-3-one

HRID 15048Notes

Reaction equation

HRID 15048 reaction equation
C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1.[O:18]1[CH:23]=[CH:22][CH2:21][CH2:20][CH2:19]1.[Br:24][C:25]1[C:26](=[O:39])[N:27]([C:32]2[CH:37]=[CH:36][C:35]([OH:38])=[CH:34][CH:33]=2)[N:28]=[CH:29][C:30]=1[Br:31]>ClCCl>[Br:24][C:25]1[C:26](=[O:39])[N:27]([C:32]2[CH:33]=[CH:34][C:35]([O:38][CH:23]3[CH2:22][CH2:21][CH2:20][CH2:19][O:18]3)=[CH:36][CH:37]=2)[N:28]=[CH:29][C:30]=1[Br:31]

Participants

5

Reactant 3

HCID 80803,4-dihydro-2H-pyranHCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)HCID 684287654,5-dibromo-2-(4-hydroxyphenyl)-2H-pyridazin-3-one

Product 1

HCID 684288614,5-dibromo-2-{4-[(tetrahydropyranyl)oxy]phenyl}-2H-pyridazin-3-oneYield 86%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A catalytic amount of pyridinium p-toluenesulfonate and 3,4-dihydro-2H-pyrane (0.8 mL, 8.89 mmols) were added to a dichloromethane (30 mL) solution of 4,5-dibromo-2-(4-hydroxyphenyl)-2H-pyridazin-3-one (1.03 g, 2.98 mmols), and stirred at room temperature for 2 hours, washed with saturated aqueous sodium bicarbonate solution and saturated brine, and dried over anhydrous potassium carbonate. Concentrating the solvent under reduced pressure, the resulting residue was crystallized from mixed solvent of ethyl acetate and hexane to provide the title compound (1.1 g, 86%).

Workup

  1. washwashed with saturated aqueous sodium bicarbonate solution and saturated brine
  2. dry with materialdried over anhydrous potassium carbonate
  3. concentrationConcentrating the solvent under reduced pressure
  4. customthe resulting residue was crystallized
  5. additionfrom mixed solvent of ethyl acetate and hexane

Sources & evidence

ORD record
ord-2d12e7bdf6a04c519d5deb44ecdd7cfa
Source dataset
uspto-grants-2010_06
Patent number
US07732456B2

Reaction notes

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