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

HRID 1452272Notes

Reaction equation

HRID 1452272 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 sodium3-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 was added and stirring was continued for a further 15 minutes. The precipitate was filtered off 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, m.p. 114°-115° C.

Workup

  1. stirringstirring
  2. waitwas continued for a further 15 minutes
  3. filtrationThe precipitate was filtered off 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-5cf95a25ac4841388922f79d04060e24
Source dataset
uspto-grants-1997_02
Patent number
US05605896

Reaction notes

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