Methanesulfonic Acid → 5-nitro-3-pyridin-2-yl-3,4-dihydro-2H-1,4-benzoxazine-3-carboxamide
Reaction equation
[N+:1]([C:4]1[C:9]2[NH:10][C:11]([C:16]3[CH:21]=[CH:20][CH:19]=[CH:18][N:17]=3)([C:14]#[N:15])[CH2:12][O:13][C:8]=2[CH:7]=[CH:6][CH:5]=1)([O-:3])=[O:2].[O-2].[Al+3].[O-2].[O-2].[Al+3].CS(O)(=O)=[O:29]>>[N+:1]([C:4]1[C:9]2[NH:10][C:11]([C:16]3[CH:21]=[CH:20][CH:19]=[CH:18][N:17]=3)([C:14]([NH2:15])=[O:29])[CH2:12][O:13][C:8]=2[CH:7]=[CH:6][CH:5]=1)([O-:3])=[O:2]Participants
Conditions
- Temperature
- 120 °C
Procedure
5-Nitro-3-pyridin-2-yl-3,4-dihydro-2H-1,4-benzoxazine-3-carbonitrile (100 mg, 0.4 mmol) was added to a vigorously stirring mixture of aluminum oxide (100 mg, 1 mmol) and methanesulfonic acid (2 mL, 30 mmol) at room temperature. The reaction mixture was then heated to 120° C. for 20 min, allowed to cool to room temperature, and partitioned between water and ethyl acetate. The organic layer was washed with brine, dried over magnesium sulfate, filtered, and concentrated to give crude product. The product was purified by FCC on silica gel eluting a hexane:ethyl acetate gradient to give 5-nitro-3-pyridin-2-yl-3,4-dihydro-2H-1,4-benzoxazine-3-carboxamide as clear oil (0.040 g. 40%). LCMS calculated for C14H13N4O4 (M+H)+: m/z=301.1. found: 301.1.
Workup
- temperatureto cool to room temperature
- custompartitioned between water and ethyl acetate
- washThe organic layer was washed with brine
- dry with materialdried over magnesium sulfate
- filtrationfiltered
- concentrationconcentrated
- customto give crude product
- customThe product was purified by FCC on silica gel eluting a hexane
Sources & evidence
- ORD record
- ord-cbf5bb5d782743e1b0722bf85853f39b
- Source dataset
- uspto-grants-2016_01
- Patent number
- US09227985B2
Reaction notes
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