Hydrogen Bromide → Fpl 52757

HRID 1606338Notes

Reaction equation

HRID 1606338 reaction equation
[CH2:1]([C:3]1[CH:4]=[C:5]([CH2:19][CH3:20])[C:6]2[O:11][C:10]([C:12]([OH:14])=[O:13])=[CH:9][C:8](=[O:15])[C:7]=2[C:16]=1[O:17]C)[CH3:2].Br.C(=O)(O)[O-].[Na+].Cl>>[CH2:1]([C:3]1[CH:4]=[C:5]([CH2:19][CH3:20])[C:6]2[O:11][C:10]([C:12]([OH:14])=[O:13])=[CH:9][C:8](=[O:15])[C:7]=2[C:16]=1[OH:17])[CH3:2]

Participants

5

Reactant 4

HCID 260Hydrogen BromideHCID 313Hydrochloric AcidHCID 516892Sodium BicarbonateHCID 21402617HCID 21402617, compound

Product 1

HCID 161944Fpl 52757

Procedure

A mixture of 5 parts of 6,8-diethyl-5-methoxy-4-oxo-4H-1-benzopyran-2-carboxylic acid and 130 parts by volume of 48% aqueous hydrobromic acid was refluxed for seven hours. The reaction mixture was cooled and excess sodium bicarbonate solution was added. The solution was acidified with concentrated hydrochloric acid and then extracted with chloroform. Evaporation of the chloroform gave a residue which on trituration with light petroleum gave 2.3 parts of 6,8-diethyl-5-hydroxy-4-oxo-4H-1-benzopyran-2-carboxylic acid, m.p. 218°-220° C (after crystallisation from ethanol).

Workup

  1. temperaturewas refluxed for seven hours
  2. temperatureThe reaction mixture was cooled
  3. extractionextracted with chloroform
  4. customEvaporation of the chloroform
  5. customgave a residue which on trituration with light petroleum
  6. customgave
  7. custom2.3 parts of 6,8-diethyl-5-hydroxy-4-oxo-4H-1-benzopyran-2-carboxylic acid, m.p. 218°-220° C (after crystallisation from ethanol)

Sources & evidence

ORD record
ord-5a3a537471db4d26906161b20add5a02
Source dataset
uspto-grants-1976_04
Patent number
US03952104

Reaction notes

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