4-tert-Butylcatechol → (2-Methyl-2-propenyl)succinic Anhydride

HRID 964966

Reaktionsgleichung

Reaktionsgleichung von HRID 964966
[C:1]1(=[O:7])[O:6][C:4](=[O:5])[CH:3]=[CH:2]1.[CH3:8][C:9]([CH3:11])=[CH2:10].C(C1C=C(O)C(=CC=1)O)(C)(C)C>C1(C)C=CC=CC=1>[C:4]1(=[O:5])[O:6][C:1](=[O:7])[CH:2]=[CH:3]1.[CH2:10]([CH:3]1[C:4](=[O:5])[O:6][C:1](=[O:7])[CH2:2]1)[C:9](=[CH2:8])[CH3:11]

Komponenten

6

Edukt 3

HCID 73814-tert-ButylcatecholHCID 7923Maleic Anhydride2×HCID 8255Isobutylene2×

Produkt 2

HCID 7923Maleic AnhydrideAusbeute 18,6 %HCID 225375(2-Methyl-2-propenyl)succinic AnhydrideAusbeute 79,8 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 1140TolueneLösungsmittel3×

Reaktionsbedingungen

Temperatur
60 °C

Versuchsvorschrift

This method describes an improved method for the synthesis of D,L-2-isobutyl-3-(methoxycarbonyl)-propionic acid (3). Maleic anhydride (750 g, 7.65 moles) was dissolved in hot toluene (500 mL), filtered, and allowed to cool thus producing a finely divided crystalline precipitate. The resulting mixture was further cooled in a refrigerator. 2-Methylpropene was condensed into cold toluene (1 L). The cold maleic anhydride suspension was transferred, with the aid of additional toluene (300 mL), to the glass liner of a Parr 2 gallon stirred autoclave. The 2-methylpropene solution was then added followed by 4-tert-butyl catechol (2 g). The autoclave was sealed and heated, with stirring, to 170° C. over 45 minutes and maintained at that temperature for an additional 9.5 hours. The reaction was then allowed to cool to 60° C. over 7 hours after which, the autoclave was vented. After an additional 1.5 hours, the internal temperature had reached 45° C. and the autoclave was opened. The solvent was removed and the residue was distilled under aspirator pressure through a 10 inch vacuum jacketed Vigreux column fitted with a partial take off head to give unreacted maleic anhydride (139.4 g, 18.6% yield) and β-methallylsuccinic anhydride (765.3 g, 79.8% yield).

Aufarbeitung

  1. filtrationfiltered
  2. temperatureto cool thus
  3. customproducing a finely divided crystalline precipitate
  4. temperatureThe resulting mixture was further cooled in a refrigerator
  5. customThe autoclave was sealed
  6. temperatureheated
  7. stirringwith stirring, to 170° C. over 45 minutes
  8. temperaturemaintained at that temperature for an additional 9.5 hours
  9. customhad reached 45° C.
  10. customThe solvent was removed
  11. distillationthe residue was distilled under aspirator pressure through a 10 inch vacuum
  12. customfitted with a partial take off head

Quellen und Nachweise

ORD-Eintrag
ord-807f6d8bd5ec4bc9ae46e261a5afaf47
Quelldatensatz
uspto-grants-1998_06
Patentnummer
US05773438

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