7-hydroxy-4-(pyridin-3-yl)coumarin → 7-Bromo-4-(pyridin-3-yl)-2H-1-benzopyran-2-one

HRID 1988202Notes

Reaction equation

HRID 1988202 reaction equation
O[C:2]1[CH:11]=[C:10]2[C:5]([C:6]([C:13]3[CH:14]=[N:15][CH:16]=[CH:17][CH:18]=3)=[CH:7][C:8](=[O:12])[O:9]2)=[CH:4][CH:3]=1.[Br-:19].[Br-].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C(O)C>[Br:19][C:2]1[CH:11]=[C:10]2[C:5]([C:6]([C:13]3[CH:14]=[N:15][CH:16]=[CH:17][CH:18]=3)=[CH:7][C:8](=[O:12])[O:9]2)=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 57028377-hydroxy-4-(pyridin-3-yl)coumarinHCID 12890784Triphenylphosphane dibromide

Product 1

HCID 233702367-Bromo-4-(pyridin-3-yl)-2H-1-benzopyran-2-one

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Commercially available 7-hydroxy-4-(3-pyridyl)coumarin (1.48 g, 6.19 mmol) and triphenylphosphine dibromide (5.22 g, 12.4 mmol) are heated in a sand bath at 320-350° C. for 1.5 h. The cooled solid is taken up with ethanol (200 ml) and silica gel (100 g) and evaporated to dryness. Column chromatography (toluene/acetone; 80:20) affords 7-bromo-4-pyridin-3-yl-2H-chromen-2-one.

Workup

  1. customevaporated to dryness

Sources & evidence

ORD record
ord-66ae623f60174ed6a65ab7512cfddc82
Source dataset
uspto-grants-2009_06
Patent number
US07553973B2

Reaction notes

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