Dimethylformamide → 2,4,4-Trimethyl-5-[(5-nitro-2-pyridyl)oxy]-3,1-benzoxazine

HRID 527661Notes

Reaction equation

[CH3:1][C:2]1[O:7][C:6]([CH3:9])([CH3:8])[C:5]2=[C:10]([OH:14])[CH:11]=[CH:12][CH:13]=[C:4]2[N:3]=1.Cl[C:16]1[CH:21]=[CH:20][C:19]([N+:22]([O-:24])=[O:23])=[CH:18][N:17]=1.CN(C=O)C>O.C(OCC)(=O)C>[CH3:1][C:2]1[O:7][C:6]([CH3:8])([CH3:9])[C:5]2[C:10]([O:14][C:16]3[CH:21]=[CH:20][C:19]([N+:22]([O-:24])=[O:23])=[CH:18][N:17]=3)=[CH:11][CH:12]=[CH:13][C:4]=2[N:3]=1

Participants

Conditions

Temperature: 70 °C

Procedure

To a suspension of 2,4,4-trimethyl-4H-3,1-benzoxazin-5-ol (Intermediate 202, 500 mg, 2.61 mmol) and 2-chloro-5-nitropyridine (410 mg, 2.58 mmol) in dry DMF (4 mL) potassium carbonate (400 mg, 2.89 mmol) was added and the resulting mixture was heated in a MW apparatus at 70° C. for 40 min. The mixture was diluted with water and ethyl acetate, phases were separated and the aqueous was back-extracted with ethyl acetate (2×20 mL). The combined organic layers were washed with brine (2×20 mL), dried over Na2SO4, filtered and concentrated and the residue was purified by flash chromatography on silica gel using cyclohexane/ethyl acetate from 70:30 to 50:50 as eluents affording the title compound (225 mg) as yellow foam.

Workup

additionwas added
customwere separated
extractionthe aqueous was back-extracted with ethyl acetate (2×20 mL)
washThe combined organic layers were washed with brine (2×20 mL)
dry with materialdried over Na2SO4
filtrationfiltered
concentrationconcentrated
customthe residue was purified by flash chromatography on silica gel

Sources & evidence

ORD record: ord-1d0116b6c0b34848a8884cc80276cbda
Source dataset: uspto-grants-2016_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09346790B2

Reaction notes

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