1,3-Dibromopropane → 8-(3-bromopropoxycarbonyl)-3-methyl-4-oxo-2-phenyl-4H-1-benzopyran

HRID 2400161Notes

Reaction equation

HRID 2400161 reaction equation
[Br:1][CH2:2][CH2:3][CH2:4]Br.[CH3:6][C:7]1[C:12](=[O:13])[C:11]2[CH:14]=[CH:15][CH:16]=[C:17]([C:18]([O-:20])=[O:19])[C:10]=2[O:9][C:8]=1[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1.[Na+]>CN(C)C=O.O>[Br:1][CH2:2][CH2:3][CH2:4][O:20][C:18]([C:17]1[C:10]2[O:9][C:8]([C:21]3[CH:22]=[CH:23][CH:24]=[CH:25][CH:26]=3)=[C:7]([CH3:6])[C:12](=[O:13])[C:11]=2[CH:14]=[CH:15][CH:16]=1)=[O:19]

Participants

5

Reactant 2

HCID 80011,3-DibromopropaneHCID 236933394h-1-benzopyran-8-carboxylic acid, 3-methyl-4-oxo-2-phenyl-, sodium salt

Product 1

HCID 199726458-(3-bromopropoxycarbonyl)-3-methyl-4-oxo-2-phenyl-4H-1-benzopyranYield 69.6%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 6228DimethylformamideSolvent

Procedure

30 g of 1,3-dibromopropane was added dropwise at ambient temperature to a suspension of 30 g of sodium 3-methyl-4-oxo-2-phenyl-4H-1-benzopyran-8-carboxylate in 150 ml of dimethylformamide and 35 ml of water. The reaction mixture was stirred at ambient temperature for 5 days. 100 ml of water were added and stirring was continued for another 15 minutes. The precipitate was filtered by suction, washed with water and purified by flash chromatography on silica gel, eluting with chloroform:ethyl acetate 95:5. The collected fractions were evaporated to dryness in vacuo and the residue was recrystallized from ethanol to give 27.7 g of the title compound, melting point 114°-115° C.

Workup

  1. stirringstirring
  2. waitwas continued for another 15 minutes
  3. filtrationThe precipitate was filtered by suction
  4. washwashed with water
  5. custompurified by flash chromatography on silica gel
  6. washeluting with chloroform:ethyl acetate 95:5
  7. customThe collected fractions were evaporated to dryness in vacuo
  8. customthe residue was recrystallized from ethanol

Sources & evidence

ORD record
ord-8e57a27e8c154aa0a2dc832a7b0cc9d4
Source dataset
uspto-grants-1995_09
Patent number
US05453518

Reaction notes

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