Reaktionsgleichung
[F:1][C:2]1[C:3]([F:16])=[C:4]2[O:9][CH2:8][CH:7]([CH3:10])[NH:6][C:5]2=[C:11]([C:13]([OH:15])=[O:14])[CH:12]=1.Cl.[CH3:18]O>>[CH3:18][O:14][C:13]([C:11]1[CH:12]=[C:2]([F:1])[C:3]([F:16])=[C:4]2[O:9][CH2:8][CH:7]([CH3:10])[NH:6][C:5]=12)=[O:15]Komponenten
Versuchsvorschrift
A solution of 2.1 g (9.1 mmol) of 7,8-difluoro-3-methyl-3,4-dihydro-2H-1,4-benzoxazine-5-carboxylic acid Example 31) in 50 mL of methanol is cooled to 0° C. and saturated with hydrogen chloride gas. The reaction is stirred at room temperature for 18 hours, recooled to 0° C. and resaturated with hydrogen chloride gas. After stirring an additional 24 hours at room temperature, the solvent is removed in vacuo and the residue is partitioned between dichloromethane/5% aqueous sodium bicarbonate (200:100 mL). The organic layer is separated, washed with 5% aqueous sodium bicarbonate, water, dried (MgSO4), filtered, and concentrated in vacuo affording 1.9 g of the title compound. 1H NMR (400 MHz, CDCl3): 7.27 (bs, 1H), 7.24 (m, 1M), 4.26 (m, 1H), 3.82 (s, 3H), 3.75 (m, 1H), 3.62 (m, 1H), 1.22 (d, 3H).
Aufarbeitung
- customrecooled to 0° C.
- stirringAfter stirring an additional 24 hours at room temperature
- customthe solvent is removed in vacuo
- customthe residue is partitioned between dichloromethane/5% aqueous sodium bicarbonate (200:100 mL)
- customThe organic layer is separated
- washwashed with 5% aqueous sodium bicarbonate, water
- dry with materialdried (MgSO4)
- filtrationfiltered
- concentrationconcentrated in vacuo
Quellen und Nachweise
- ORD-Eintrag
- ord-09619287c00c441c8ecc25cb12e6c37d
- Quelldatensatz
- uspto-grants-2009_09
- Patentnummer
- US07582627B2
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