Trimethyl orthoformate → 1,3-Benzoxazole-7-carboxylic acid
Reaktionsgleichung
[NH2:1][C:2]1[C:3]([OH:11])=[C:4]([CH:8]=[CH:9][CH:10]=1)[C:5]([OH:7])=[O:6].[CH:12](OC)(OC)OC>>[O:11]1[C:3]2[C:4]([C:5]([OH:7])=[O:6])=[CH:8][CH:9]=[CH:10][C:2]=2[N:1]=[CH:12]1Komponenten
3
Versuchsvorschrift
A solution of 3-amino-2-hydroxy-benzoic acid (12.5 mmol) in trimethyl orthoformate (19.2 mL) is heated to reflux for 20 h and concentrated in vacuo. The residue is washed three times with hot MeOH, the filtrates are combined and the solvent is removed in vacuo to give the desired product which is used without further purification. 1H-NMR (DMSO-d6): δ=13.4 (bs, 1H); 8.87 (s, 1H); 8.08 (d, J=8.0 Hz, 1H); 7.96 (d, J=7.5 Hz, 1H); 7.52 (t, J=7.9 Hz, 1H).
Aufarbeitung
- temperatureto reflux for 20 h
- concentrationconcentrated in vacuo
- washThe residue is washed three times with hot MeOH
- customthe solvent is removed in vacuo
Quellen und Nachweise
- ORD-Eintrag
- ord-a3fc63cda01540df82fa25a92ae279d7
- Quelldatensatz
- uspto-grants-2012_10
- Patentnummer
- US08288435B2
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