Water → 6-Bromo-3-formylchromone

HRID 436277Notes

Reaction equation

HRID 436277 reaction equation
O.O.[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[Na+].[Na+].[Br:14][C:15]1[CH:16]=[C:17]2[C:22](=[CH:23][CH:24]=1)[O:21][CH:20]=[C:19]([CH2:25][OH:26])[C:18]2=[O:27].O>C(O)(=O)C>[Br:14][C:15]1[CH:16]=[C:17]2[C:22](=[CH:23][CH:24]=1)[O:21][CH:20]=[C:19]([CH:25]=[O:26])[C:18]2=[O:27]

Participants

5

Reactant 3

HCID 962WaterHCID 108005Sodium dichromate dihydrateHCID 16769513HCID 16769513, compound

Product 1

HCID 6143096-Bromo-3-formylchromone

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Conditions

Temperature
40 °C

Procedure

A warm (40° C.) solution of 29.8 g. (0.1 mole) of sodium dichromate dihydrate in 80 ml of glacial acetic acid is added over a 5-minute period to a stirred, warm (60° C.) solution of 25.5 g. (0.1 mole) of 6-bromo-3-(hydroxymethyl)chromone in 300 ml of glacial acetic acid. The temperature rises to 72° C. After one-half hour, water (1400 ml) is added and the mixture is heated at 80° C. for a few minutes. The mixture is cooled and filtered to give 13.6 g. (54%) of good quality aldehyde. Recrystallization from ethyl acetate gives pure 6-bromo-3-formylchromone having mp 186°-188° C.

Workup

  1. temperaturewarm (60° C.) solution of 25.5 g
  2. customrises to 72° C
  3. waitAfter one-half hour
  4. temperaturethe mixture is heated at 80° C. for a few minutes
  5. temperatureThe mixture is cooled
  6. filtrationfiltered
  7. customto give 13.6 g
  8. customRecrystallization from ethyl acetate

Sources & evidence

ORD record
ord-7e6a666f5713469ab50145c22330580c
Source dataset
uspto-grants-1977_02
Patent number
US04008252

Reaction notes

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