Boron tribromide → 6-hydroxy-2H-chromen-2-one

HRID 2118376Notes

Reaction equation

HRID 2118376 reaction equation
CO[C:3]1[CH:13]=[CH:12][C:11]([O:14]C)=[CH:10][C:4]=1[CH:5]=[CH:6][C:7]([OH:9])=[O:8].B(Br)(Br)Br>>[OH:14][C:11]1[CH:10]=[C:4]2[C:3](=[CH:13][CH:12]=1)[O:8][C:7](=[O:9])[CH:6]=[CH:5]2

Participants

3

Reactant 2

HCID 25134Boron tribromideHCID 1145783-(2,5-Dimethoxyphenyl)-2-propenoic acid

Product 1

HCID 994776-hydroxy-2H-chromen-2-one

Procedure

In scheme F, 2,5-dimethoxycinnamic acid 15 is treated with boron tribromide (BBr3) to form 6-hydroxycoumarin 16. 6-Hydroxycoumarin 16 can be protected as the bis-methoxymethyl ether (MOM) 17a using N,N-diisopropylethylamine (iPr2NEt) and MOMCl or as the benzyl ether (Bn) 17b using cesium carbonate (CsCO3) and benzyl bromide (BnBr).

Sources & evidence

ORD record
ord-a4ee39c3f94d4a8e8019809566507cef
Source dataset
uspto-grants-2008_10
Patent number
US07442812B2

Reaction notes

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