p-Toluenesulfonic acid → HCID 20279748, compound

HRID 1247866Notes

Reaction equation

HRID 1247866 reaction equation
[CH2:1]([O:7][C:8]1[CH:15]=[CH:14][C:11]([CH:12]=[O:13])=[CH:10][CH:9]=1)[CH2:2][CH2:3][CH2:4][CH2:5][CH3:6].C([O:18][C:19](=[O:30])[C:20](CO)([CH2:26]O)[C:21](OCC)=[O:22])C.C1(C)C=CC(S(O)(=O)=O)=CC=1.[OH-].[K+]>C1C=CC=CC=1.C(O)C.CCCCCC>[CH2:1]([O:7][C:8]1[CH:15]=[CH:14][C:11]([CH:12]2[O:22][CH2:21][CH:20]([C:19]([OH:30])=[O:18])[CH2:26][O:13]2)=[CH:10][CH:9]=1)[CH2:2][CH2:3][CH2:4][CH2:5][CH3:6]

Participants

8

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 14797Potassium HydroxideHCID 79816p-(Hexyloxy)benzaldehydeHCID 311844Propanedioic acid, 2,2-bis(hydroxymethyl)-, 1,3-diethyl ester

Product 1

HCID 20279748HCID 20279748, compound

Reagents, catalysts & solvents 3

HCID 241BenzeneSolventHCID 702EthanolSolventHCID 8058HexaneSolvent

Conditions

Temperature
0 °C

Procedure

20.6 g (0.1 mol) 4-n-hexoxybenzaldehyde and 24.2 g (0.11 mol) bis-hydroxymethyl-malonic acid-diethyl ester are heated in 150 ml benzene in a corresponding amount of 0.2 g p-toluenesulfonic acid, while stirring for 8 hours. After cooling, the benzene is carefully washed with 2% NaHCO3 solution, then with water, and then distilled under vacuum (rotating evaporator), with the residue being recrystallized from alcohol (2-(4-n-hexoxyphenyl)-1,3-dioxane-5,5-dicarboxylic acid-diethyl ester I). The yield at I is 31 g (76% of theoretical). I melts at 30° C. (from n-hexane). 31 g (0.074 mol) I and 18 g (0.32 mol) KOH in 150 ml 95% ethanol is heated for one hour at reflux in the continued preparation. Ethanol is then distilled from the reaction residue, water added to the residue, and the aqueous phase concentrated to 30-50 ml. After addition of 100 ml ether, it is cooled to 0° C. and concentrated HCl is added while stirring (up to pH 1). Subsequently, the ether fraction is immediately separated, washed with water, dried with Na2SO4, and the solvent removed in the rotating evaporator. The residue (16.5 g, 62% of theoretical) of 2(4-n-hexoxyphenyl)-1,3-dioxane-5,5-dicarboxylic acid (decomposition above 135° C.) is decarboxylized with a water jet vacuum pump at 120° to 170° C. Having completed the brisk CO2 development, the residue of benzene or cyclohexane is recrystallized. The yield of 5 n is 63% of theoretical. The melting point of 5 n is 176° to 178° C. Additional examples are listed in Table 5.

Workup

  1. temperatureAfter cooling
  2. washthe benzene is carefully washed with 2% NaHCO3 solution
  3. distillationwith water, and then distilled under vacuum (rotating evaporator), with the residue
  4. custombeing recrystallized from alcohol (2-(4-n-hexoxyphenyl)-1,3-dioxane-5,5-dicarboxylic acid-diethyl ester I)
  5. customThe yield at I
  6. temperatureat reflux in the continued preparation
  7. distillationEthanol is then distilled from the reaction residue, water
  8. additionadded to the residue
  9. concentrationthe aqueous phase concentrated to 30-50 ml
  10. additionAfter addition of 100 ml ether, it
  11. additionconcentrated HCl is added
  12. stirringwhile stirring (up to pH 1)
  13. customSubsequently, the ether fraction is immediately separated
  14. washwashed with water
  15. dry with materialdried with Na2SO4
  16. customthe solvent removed in the rotating evaporator
  17. customThe residue (16.5 g, 62% of theoretical) of 2(4-n-hexoxyphenyl)-1,3-dioxane-5,5-dicarboxylic acid (decomposition above 135° C.)
  18. customis decarboxylized with a water jet vacuum pump at 120° to 170° C
  19. customthe residue of benzene or cyclohexane is recrystallized
  20. customis 176° to 178° C

Sources & evidence

ORD record
ord-6a4043ad2cff42a0bcce3cd0485e2d29
Source dataset
uspto-grants-1985_06
Patent number
US04521327

Reaction notes

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