2,4-Dihydroxybenzaldehyde → HCID 56692933, compound

HRID 2045736Notes

Reaction equation

HRID 2045736 reaction equation
[CH2:1]([O:5][C:6]1[CH:11]=[CH:10][C:9]([CH2:12][C:13]([OH:15])=[O:14])=[CH:8][CH:7]=1)[CH2:2][CH2:3][CH3:4].O[C:17]1[CH:24]=[C:23]([OH:25])[CH:22]=[CH:21][C:18]=1[CH:19]=O>C(OC(=O)C)(=O)C.C(N(CC)CC)C>[CH2:1]([O:5][C:6]1[CH:7]=[CH:8][C:9]([C:12]2[C:13](=[O:15])[O:14][C:21]3[C:18]([CH:19]=2)=[CH:17][CH:24]=[C:23]([OH:25])[CH:22]=3)=[CH:10][CH:11]=1)[CH2:2][CH2:3][CH3:4]

Participants

5

Reactant 2

HCID 72132,4-DihydroxybenzaldehydeHCID 78304Acetic acid, (p-butoxyphenyl)-

Product 1

HCID 56692933HCID 56692933, compound

Reagents, catalysts & solvents 2

HCID 7918Acetic AnhydrideSolventHCID 8471TriethylamineSolvent

Procedure

89.5 g (0.43 mol) of 4-butoxyphenylacetic acid (prepared by the method of McElvain, Carney; J. Am. Chem. Soc. 1946 (68), 2592-2599) and 30.0 g (0.22 mol) of 2,4-dihydroxybenzaldehyde are heated at 120° C. for 5 h in 100 ml of acetic anhydride and 120 ml of triethylamine. The still-hot solution is subsequently added to 3 l of ice-water, and the precipitated product is filtered off with suction and suspended in 1 l of water and 1.4 l of ethanol. After dropwise addition of 190 ml of conc. sulfuric acid, the batch is heated under reflux for 4 h and added to 3 l of water, and the precipitated product is filtered off with suction. The crude product is filtered through silica gel with hot toluene/ethyl acetate (1:1), the solvent is evaporated in vacuo, and the residue is recrystallised from toluene, giving 3-(4-butoxyphenyl)-7-hydroxychromen-2-one as colourless crystals.

Workup

  1. filtrationthe precipitated product is filtered off with suction
  2. additionAfter dropwise addition of 190 ml of conc. sulfuric acid
  3. temperaturethe batch is heated
  4. temperatureunder reflux for 4 h
  5. additionadded to 3 l of water
  6. filtrationthe precipitated product is filtered off with suction
  7. filtrationThe crude product is filtered through silica gel with hot toluene/ethyl acetate (1:1)
  8. customthe solvent is evaporated in vacuo
  9. customthe residue is recrystallised from toluene

Sources & evidence

ORD record
ord-3c5d251a63444791b379bee585abec58
Source dataset
uspto-grants-2013_11
Patent number
US08592007B2

Reaction notes

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