Reaktion #69733

Reaktionsgleichung

Acetic anhydride

3-methoxyphthalic acid

→

3-methoxyphthalic anhydride

Ausbeute 99.1%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturat reflux for 4 hours
2. 2
   Sonstigewas removed in vacuo
3. 3
   Sonstigethe resulting solid material was dried in a vacuum oven at 50° C. overnight

Vorschrift

Acetic anhydride (70 ml) was added to a mixture of 3-methoxyphthalic acid (51.0 g, 0.26 mol) in anhydrous tetrahydrofuran (250 ml) and the mixture was stirred and held at reflux for 4 hours. Upon cooling to room temperature the solvent was removed in vacuo and the resulting solid material was dried in a vacuum oven at 50° C. overnight to afford 3-methoxyphthalic anhydride (45.9 g, 99%) as a colourless solid. 1H NMR (DMSO-d6) 7.97 (1H, dd), 7.63 (1H, d), 7.60 (1H, d), 4.02 (3H, s). MS: [M+H]+ 179.

Quelle