Acetic Acid → Acetic Anhydride

HRID 745152Notes

Reaction equation

HRID 745152 reaction equation
[C:1]([OH:4])(=[O:3])[CH3:2].[CH3:5][C:6]1[CH:11]=[CH:10][C:9]([CH:12]=[CH2:13])=[CH:8][N:7]=1.[OH-].[Na+].[O:16]1[CH2:20][CH2:19][CH2:18][CH2:17]1>CO>[CH3:17][C:18]1[CH:19]=[C:20]([CH3:1])[CH:5]=[C:6]([CH3:11])[N:7]=1.[CH:12]1[C:9]([CH:8]=[O:16])=[CH:10][CH:11]=[C:2]([CH:1]=[O:4])[CH:13]=1.[C:1]([O:4][C:17](=[O:16])[CH3:18])(=[O:3])[CH3:2]

Participants

8

Reactant 4

HCID 176Acetic Acid2×HCID 8028TetrahydrofuranHCID 88172-Methyl-5-vinylpyridineHCID 14798Sodium Hydroxide

Product 3

HCID 7918Acetic AnhydrideHCID 79532,4,6-TrimethylpyridineHCID 12173Terephthalaldehyde

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
120 °C

Procedure

3.0 Moles of 2,4,6-trimethylpyridine, 4.5 moles of terephthaldehyde, 9.0 moles of acetic acid and 9.0 moles of acetic anhydride are prereacted at 140° C. for 6 hours. The reaction mixture is then cooled to 120° C. and 4.5 moles of 2-methyl-5-vinylpyridine is added. Stirring at 120° C. is continued for 8 hours. The reaction mixture is cooled, and the acetic acid is neutralized with 10% sodium hydroxide. The organic phase is separated, dissolved in tetrahydrofuran (THF) and filtered. The radical inhibitors o-aminophenol and t-butylcatechol are added at the 0.05% and 0.1% levels, respectively. VPSP is isolated by pouring the THF solution into methanol to obtain a solid precipitate. The solid is dried in vacuo to constant weight. The material thus obtained has a melting point exotherm by DSC at 99° C. and a molecular weight of greater than 3000 as determined by vapor pressure osmometry.

Workup

  1. temperatureThe reaction mixture is cooled
  2. customThe organic phase is separated
  3. dissolutiondissolved in tetrahydrofuran (THF)
  4. filtrationfiltered
  5. additionThe radical inhibitors o-aminophenol and t-butylcatechol are added at the 0.05% and 0.1% levels
  6. customVPSP is isolated
  7. customto obtain a solid precipitate
  8. customThe solid is dried in vacuo to constant weight
  9. customThe material thus obtained
  10. customat 99° C.

Sources & evidence

ORD record
ord-3975cad8ee194b838cb63ecb025f291f
Source dataset
uspto-grants-1986_07
Patent number
US04598007

Reaction notes

Loading…