Boron tribromide → 4'-Amino-5,7-dihydroxy-6-methoxyflavone

HRID 1095277Notes

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]C)[C:11]([O:19][CH3:20])=[C:10]([O:21]C)[CH:9]=3)=[CH:4][CH:3]=1.B(Br)(Br)Br>C(Cl)Cl>[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]([OH:17])[C:11]([O:19][CH3:20])=[C:10]([OH:21])[CH:9]=3)=[CH:4][CH:3]=1

Participants

Conditions

Temperature: -20 °C

Procedure

To a solution of the flavone 10a (130 mg, 0.4 mmol) in CH2Cl2 (10 mL) was added a 1M solution of boron tribromide (1.5 mL, 1.5 mmol) in CH2Cl2 at −78° C. The solution was stirred for an additional 2 h and at −20° C. for 5 h, then quenched with water (10 mL). The precipitate was collected by filtration to give crude product 10b (51 mg, 43%). 1H NMR (400 MHz, DMSO) δ 3.89 (s, 3H), 6.68 (s, 1H), 6.74 (d, J=8.8 Hz, 2H), 6.87 (s, 1H), 7.82 (d, J=8.8 Hz, 2H).

Workup

customquenched with water (10 mL)
filtrationThe precipitate was collected by filtration

Sources & evidence

ORD record: ord-7d16d0d7cc9f44ceab21f186636c8c57
Source dataset: uspto-grants-2012_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08138165B2

Reaction notes

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