Resorcinol → 2-(6-Hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acid

HRID 1683370Notes

Reaction equation

HRID 1683370 reaction equation
[C:1]1([CH:8]=[CH:7][CH:6]=[C:4]([OH:5])[CH:3]=1)[OH:2].[C:9]1(=[O:19])[O:14][C:12](=O)[C:11]2=[CH:15][CH:16]=[CH:17][CH:18]=[C:10]12>>[CH:16]1[CH:17]=[CH:18][C:10]([C:9]([OH:14])=[O:19])=[C:11]([C:12]2[C:6]3[CH:4]=[CH:3][C:1]([OH:2])=[CH:8][C:7]=3[O:5][C:4]3[C:6]=2[CH:7]=[CH:8][C:1]([CH:3]=3)=[O:2])[CH:15]=1

Participants

3

Reactant 2

HCID 5054Resorcinol2×HCID 6811Phthalic Anhydride

Product 1

HCID 33832-(6-Hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acidYield 89.9%

Procedure

Resorcinol (470 g, technical grade 99.4%, white flakes) was added to a one-liter jacketed glass vessel and heated to 135 C. in order to melt the resorcinol. Once melted, phthalic anhydride (124 g, technical grade 99.7%, white flakes) was added to the vessel, and the reaction mixture was blanketed with nitrogen, mixed and heated to 200 C. The reaction mixture was held at 200-215 C. for approximately 2 hours while the water (24 g) was removed by distillation. Upon completion, the reaction mixture was cooled to 185 C. and quenched with water by transferring the reaction mixture under nitrogen to a stirred vessel containing water (approximately 500 ml). The vessel was then rinsed with water to transfer all of the precipitated product. The combined product slurry in water was digested at 75 C. (to dissolve any unreacted intermediates) and cooled to 35 C. The product was recovered by vacuum filtration in the form of a filter cake. This filter cake was washed free of dissolved impurities, such as resorcinol, by mixing and heating with fresh water (approximately 1L), filtering and rinsing with about 800 ml boiling hot water. This cake upon drying yielded fluorescein (250.1 g).

Workup

  1. temperatureheated to 135 C
  2. additionmixed
  3. temperatureheated to 200 C
  4. customfor approximately 2 hours while the water (24 g) was removed by distillation
  5. temperatureUpon completion, the reaction mixture was cooled to 185 C
  6. customand quenched with water
  7. additioncontaining water (approximately 500 ml)
  8. washThe vessel was then rinsed with water
  9. dissolution(to dissolve any unreacted intermediates) and
  10. temperaturecooled to 35 C
  11. filtrationThe product was recovered by vacuum filtration in the form of a filter cake
  12. washThis filter cake was washed free of dissolved impurities, such as resorcinol
  13. additionby mixing
  14. temperatureheating with fresh water (approximately 1L),
  15. filtrationfiltering
  16. washrinsing with about 800 ml
  17. customThis cake upon drying

Sources & evidence

ORD record
ord-a51f8c9db662417f840bffd54d7bf6b6
Source dataset
uspto-grants-1997_06
Patent number
US05637733

Reaction notes

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