Water → 6-Bromochromone-3-carboxylic acid

HRID 2058950Notes

Reaction equation

HRID 2058950 reaction equation
[C:1]([C:3]1[C:12](=[O:13])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([Br:14])[CH:10]=2)[O:5][CH:4]=1)#N.N([O-])=[O:16].[Na+].[OH2:19]>S(=O)(=O)(O)O>[Br:14][C:9]1[CH:10]=[C:11]2[C:6](=[CH:7][CH:8]=1)[O:19][CH:1]=[C:3]([C:4]([OH:16])=[O:5])[C:12]2=[O:13]

Participants

5

Reactant 3

HCID 962Water2×HCID 7030366-Bromo-3-cyanochromoneHCID 23668193Sodium Nitrite

Product 1

HCID 27568986-Bromochromone-3-carboxylic acid

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

26 g of the product of step (b) are stirred overnight in 150 ml of conc. sulphuric acid at room temperature. The mixture is then diluted with 10 ml of water and cooled to 0°. Under stirring, a solution of 15 g of sodium nitrite in 30 ml of water is introduced slowly under the liquid surface, the temperature being maintained by cooling at 15°. After addition, the mixture is warmed at 70° for 1 hour and poured over ice and the precipitate is suction filtered off, suspended in 600 ml of acetone, refluxed, hot-filtered and the filtrate then evaporated on a rotary evaporator. The residue is recrystallised from chloroform, to obtain the heading compound, m.p. 260°-264°.

Workup

  1. temperaturecooled to 0°
  2. temperaturethe temperature being maintained
  3. temperatureby cooling at 15°
  4. additionAfter addition
  5. temperaturethe mixture is warmed at 70° for 1 hour
  6. additionpoured over ice
  7. filtrationfiltered off
  8. temperaturerefluxed
  9. filtrationhot-filtered
  10. customthe filtrate then evaporated on a rotary evaporator
  11. customThe residue is recrystallised from chloroform
  12. customto obtain the heading compound, m.p. 260°-264°

Sources & evidence

ORD record
ord-eeac1303aefb4dce8191dd94ffa4d5a7
Source dataset
uspto-grants-1982_03
Patent number
US04320133

Reaction notes

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