8-Methoxypsoralen → 4-Bromo-9-methoxy-7h-furo[3,2-g]chromen-7-one

HRID 36837Notes

Reaction equation

HRID 36837 reaction equation
[CH3:1][O:2][C:3]1[C:11]2[O:12][C:13]([CH:15]=[CH:16][C:10]=2[CH:9]=[C:5]2[CH:6]=[CH:7][O:8][C:4]=12)=[O:14].[Br:17]Br.S([O-])([O-])(=O)=S.[Na+].[Na+].[NH4+].[OH-]>O1CCCC1>[CH3:1][O:2][C:3]1[C:11]2[O:12][C:13]([CH:15]=[CH:16][C:10]=2[C:9]([Br:17])=[C:5]2[CH:6]=[CH:7][O:8][C:4]=12)=[O:14]

Participants

6

Reactant 4

HCID 41148-MethoxypsoralenHCID 14923Ammonium HydroxideHCID 24408BromineHCID 24477Sodium Thiosulfate

Product 1

HCID 2400484-Bromo-9-methoxy-7h-furo[3,2-g]chromen-7-oneYield 73.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

8-methoxypsoralen (8-MOP, Aldrich, Milwaukee, Wis., 0.75 g, 3.5 m mol) was dissolved in tetrahydrofuran (THF, 75 mL), Bromine (1.5 mL, 3.5 mmol) in THF (5 mL) was added dropwise. The resulting mixture was stirred at room temperature for overnight. 10% Sodium thiosulfate (5 mL) was added and the solution was basified using conc. aqueous NH4OH, and then extracted twice with chloroform. The organic layer was recrystallized from chloroform to give the product 5-bromo-8-methoxypsoralen (0.75 g, 73.5% yield).

Workup

  1. extractionextracted twice with chloroform
  2. customThe organic layer was recrystallized from chloroform

Sources & evidence

ORD record
ord-32f0189489ac4c28bee24628766de52c
Source dataset
uspto-grants-1995_05
Patent number
US05418130

Reaction notes

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