Salicylaldehyde → HCID 21325023, compound

HRID 26221Notes

Reaction equation

HRID 26221 reaction equation
N1CC[CH2:4][CH2:3][CH2:2]1.[OH:7][C:8]1[CH:9]=[C:10]([CH:15]=[CH:16][C:17]=1[C:18](=[O:20])[CH3:19])[C:11]([O:13]C)=[O:12].[CH:21](=O)[C:22]1[C:23](=[CH:25][CH:26]=[CH:27][CH:28]=1)[OH:24]>C(O)C.O>[C:11]([C:10]1[CH:9]=[C:8]2[C:17]([C:18](=[O:20])[CH:19]=[C:21]([C:22]3[CH:28]=[CH:27][CH:26]=[CH:25][C:23]=3[O:24][CH:3]([CH3:4])[CH3:2])[O:7]2)=[CH:16][CH:15]=1)([OH:13])=[O:12]

Participants

6

Reactant 3

HCID 6998SalicylaldehydeHCID 8082PiperidineHCID 22610067Methyl 4-acetyl-3-hydroxybenzoate

Product 1

HCID 21325023HCID 21325023, compound

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

Piperidine (200 m) was added to a solution consisting of methyl 3-hydroxy-4-acetyl-benzoate (15 g) and salicylaldehyde (15 g) in absolute ethanol (400 ml); the mixture was kept at reflux temperature for 40 hours. After cooling, acidification with hydrochloric acid and extraction with ethylacetate, the organic phase was washed with K2CO 3 5%, and with water, then evaporated to dryness. The residue, so obtained (11 g), was dissolved in n-amylic alcohol (200 ml) by adding SeO2 (11 g) and the solution was kept at reflux temperature for 18 hours. After cooling, the residue was filtered off and the amylic alcohol was distilled in a steam current: the residue of the distillation was recovered by extraction with chloroform, to give, after crystallisation from ethanol, 7-carbomethoxy-2'-hydroxy-flavone (6.3 g), which was reacted in dimethylformamide (30 ml) with 2-bromo-propane (3.5 g) and anhydrous potassium carbonate (4 g) at 70° C. for 18 hours. After cooling, the mixture was diluted with water (200 ml), and then filtered, so obtaining 7-carbomethoxy-2'-isopropoxy-flavone (7.9 g) which was subsequently hydroylsed by treatment with the stoichiometric quantity of a solution of potassium hydroxide 1% in ethanol 95% at reflux temperature for 30 minutes. After cooling, acidification with acetic acid, dilution with water, filtration, and subsequent crystallisation from ethanol, 7-carboxy-2'-isopropoxy-flavone (5.7 g) was obtained.

Workup

  1. temperatureat reflux temperature for 40 hours
  2. temperatureAfter cooling
  3. extractionacidification with hydrochloric acid and extraction with ethylacetate
  4. washthe organic phase was washed with K2CO 3 5%
  5. customwith water, then evaporated to dryness
  6. customThe residue, so obtained (11 g)
  7. temperatureat reflux temperature for 18 hours
  8. temperatureAfter cooling
  9. filtrationthe residue was filtered off
  10. distillationthe amylic alcohol was distilled in a steam current
  11. distillationthe residue of the distillation
  12. customwas recovered by extraction with chloroform
  13. customto give
  14. customafter crystallisation from ethanol, 7-carbomethoxy-2'-hydroxy-flavone (6.3 g), which
  15. customwas reacted in dimethylformamide (30 ml) with 2-bromo-propane (3.5 g) and anhydrous potassium carbonate (4 g) at 70° C. for 18 hours
  16. temperatureAfter cooling
  17. filtrationfiltered
  18. temperatureat reflux temperature for 30 minutes
  19. temperatureAfter cooling
  20. filtrationacidification with acetic acid, dilution with water, filtration, and subsequent crystallisation from ethanol

Sources & evidence

ORD record
ord-c82d5e99686e4b2399ad1c093c1633cb
Source dataset
uspto-grants-1979_04
Patent number
US04148900

Reaction notes

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