Pyridine → 4'-(Methylsulfonamido)-5,6,7-trimethoxyflavone

HRID 1095278Notes

Reaction equation

[NH2:1][C:2]1[CH:24]=[CH:23][C:5]([C:6]2[O:7][C:8]3[C:13]([C:14](=[O:16])[CH:15]=2)=[C:12]([O:17][CH3:18])[C:11]([O:19][CH3:20])=[C:10]([O:21][CH3:22])[CH:9]=3)=[CH:4][CH:3]=1.N1C=CC=CC=1.[CH3:31][S:32](Cl)(=[O:34])=[O:33].C([O-])(O)=O.[Na+]>C(Cl)Cl>[CH3:31][S:32]([NH:1][C:2]1[CH:3]=[CH:4][C:5]([C:6]2[O:7][C:8]3[C:13]([C:14](=[O:16])[CH:15]=2)=[C:12]([O:17][CH3:18])[C:11]([O:19][CH3:20])=[C:10]([O:21][CH3:22])[CH:9]=3)=[CH:23][CH:24]=1)(=[O:34])=[O:33]

Participants

Conditions

Temperature: 0 °C

Procedure

The aminoflavone 10a (0.13 g, 0.40 mmol) was dissolved in 5 mL of dry methylene chloride, then 2 mL of freshly distilled pyridine was added. The solution was cooled to 0° C. then was dropwise added freshly distilled methanesulfonyl chloride (0.6 mmol). The reaction mixture was stirred at 0° C. for 1 h and at room temperature for an additional hour, then poured into 30 mL saturated NaHCO3. The resulting mixture was extracted with methylene chloride. The combined organic layers were washed with 5% HCl to remove pyridine, dried over Na2SO4 and concentrated. The residue was purified by column chromatography on silica gel (acetone:toluene=1:5) to give 10e (0.12 g, 74%). 1H NMR (400 MHz, Acetone) δ 3.11 (s, 3H), 3.81 (s, 3H), 3.87 (s, 3H), 4.00 (s, 3H), 6.60 (s, 1H), 7.11 (s, 1H), 7.50 (d, J=8.8 Hz, 2H), 8.02 (d, J=8.8 Hz, 2H).

Workup

extractionThe resulting mixture was extracted with methylene chloride
washThe combined organic layers were washed with 5% HCl
customto remove pyridine
dry with materialdried over Na2SO4
concentrationconcentrated
customThe residue was purified by column chromatography on silica gel (acetone:toluene=1:5)

Sources & evidence

ORD record: ord-3061572d4ebc4805bd92648daed16035
Source dataset: uspto-grants-2012_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08138165B2

Reaction notes

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