N-bromobutanimide → 7-Amino-4-bromo-2-ethoxycarbonyl-2,3-dihydro-2-methylbenzofuran

HRID 440709Notes

Reaction equation

HRID 440709 reaction equation
[NH2:1][C:2]1[C:10]2[O:9][C:8]([C:12]([O:14][CH2:15][CH3:16])=[O:13])([CH3:11])[CH2:7][C:6]=2[CH:5]=[CH:4][CH:3]=1.[Br:17]N1C(=O)CCC1=O>CN(C)C=O.[Cl-].[Li+]>[NH2:1][C:2]1[C:10]2[O:9][C:8]([C:12]([O:14][CH2:15][CH3:16])=[O:13])([CH3:11])[CH2:7][C:6]=2[C:5]([Br:17])=[CH:4][CH:3]=1

Participants

5

Reactant 2

HCID 67184N-bromobutanimideHCID 224047847-Amino-2-ethoxycarbonyl-2,3-dihydro-2-methylbenzofuran

Product 1

HCID 224047637-Amino-4-bromo-2-ethoxycarbonyl-2,3-dihydro-2-methylbenzofuranYield 106.6%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 433294Lithium ChlorideSolvent

Procedure

A stirred solution of 1.2 grams (0.005 mole) of 7-amino-2-ethoxycarbonyl-2,3-dihydro-2-methylbenzofuran in 50 mL of N,N-dimethylformamide was cooled in an ice-water bath, and 1.0 gram (0.005 mole) of N-bromosuccinimide was added. Upon completion of the addition, the reaction mixture was stirred at the ice-water bath temperature for about one hour and then allowed to warm to ambient temperature, where it stirred for about 18 hours. The reaction mixture was diluted with an aqueous 10% lithium chloride solution, and extracted with two portions of ethyl acetate. The combined extracts were washed with 50 mL of an aqueous 10% lithium chloride solution and dried with magnesium sulfate. The mixture was filtered, and the filtrate was concentrated under reduced pressure to a residual oil, which was subjected to column chromatography on silica gel, with 1:4 ethyl acetate:heptane as the eluant. The product-containing fractions were combined and concentrated under reduced pressure, yielding 1.6 grams of 7-amino-4-bromo-2-ethoxycarbonyl-2,3-dihydro-2-methylbenzofuran. The NMR spectrum was consistent with the proposed structure.

Workup

  1. additionUpon completion of the addition
  2. extractionextracted with two portions of ethyl acetate
  3. washThe combined extracts were washed with 50 mL of an aqueous 10% lithium chloride solution
  4. dry with materialdried with magnesium sulfate
  5. filtrationThe mixture was filtered
  6. concentrationthe filtrate was concentrated under reduced pressure to a residual oil, which
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-1fcc8479db1a47e2b59a64222907d844
Source dataset
uspto-grants-1996_05
Patent number
US05521147

Reaction notes

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