1,3-Dibromopropane → methyl 3-[7-(3-bromopropoxy)3,4-dihydro-2-methyl-8-propyl-2H-1-benzopyran-2-yl]propanoate

HRID 978748Notes

Reaction equation

HRID 978748 reaction equation
[OH:1][C:2]1[CH:18]=[CH:17][C:5]2[CH2:6][CH2:7][C:8]([CH2:11][CH2:12][C:13]([O:15][CH3:16])=[O:14])([CH3:10])[O:9][C:4]=2[C:3]=1[CH2:19][CH2:20][CH3:21].[Br:22][CH2:23][CH2:24][CH2:25]Br.[OH-].[Na+]>S([O-])(O)(=O)=O.C([N+](CCCC)(CCCC)CCCC)CCC.C(Cl)Cl>[Br:22][CH2:23][CH2:24][CH2:25][O:1][C:2]1[CH:18]=[CH:17][C:5]2[CH2:6][CH2:7][C:8]([CH2:11][CH2:12][C:13]([O:15][CH3:16])=[O:14])([CH3:10])[O:9][C:4]=2[C:3]=1[CH2:19][CH2:20][CH3:21]

Participants

6

Reactant 3

HCID 80011,3-DibromopropaneHCID 14798Sodium HydroxideHCID 14882982methyl 3-(3,4-dihydro-7-hydroxy-2-methyl-8-propyl-2H-1-benzopyran-2-yl)propanoate

Product 1

HCID 14882983methyl 3-[7-(3-bromopropoxy)3,4-dihydro-2-methyl-8-propyl-2H-1-benzopyran-2-yl]propanoateYield 79%

Reagents, catalysts & solvents 2

HCID 94433Tetrabutylammonium hydrogen sulfateCatalystHCID 6344DichloromethaneSolvent

Procedure

To a solution of 1.7 g (5.51 mmole) of the title compound from Example 10, 1.1 ml (11 mmoles) of 1,3-dibromopropane and 1.9 g (11 mmole) of tetrabutylammonium hydrogen sulfate in 12 ml of methylene chloride was added 5.5 ml of 2M sodium hydroxide solution. The reaction mixture was heated to reflux for 15 minutes and cooled. The organic layer was separated, washed with brine, dried over sodium sulfate, filtered, and concentrated to dryness. Chromatography of the residue on silica gel using 10% ethyl acetate/hexane as eluent gave 1.8 g of the title compound as an oil. Structure assignment was confirmed by nmr and infrared spectra.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 15 minutes
  3. temperaturecooled
  4. customThe organic layer was separated
  5. washwashed with brine
  6. dry with materialdried over sodium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated to dryness

Sources & evidence

ORD record
ord-50aa91628f3e46aca7bb81f8dc45aaa1
Source dataset
uspto-grants-1987_05
Patent number
US04665203

Reaction notes

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