2-(Bromomethyl)-1-benzofuran → HCID 69627030, compound
Reaction equation
[C:1]([O:5][C:6]([C:8]1(C2OC3C=CC=CC=3C=2)[CH2:10][CH:9]1CO)=[O:7])([CH3:4])([CH3:3])[CH3:2].Br[CH2:23][C:24]1[O:25][C:26]2[CH:32]=[CH:31][CH:30]=[CH:29][C:27]=2[CH:28]=1.C(OC(C1([Li])CC1)=O)(C)(C)C>>[C:1]([O:5][C:6]([C:8]1([CH2:23][C:24]2[O:25][C:26]3[CH:32]=[CH:31][CH:30]=[CH:29][C:27]=3[CH:28]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]Participants
Procedure
An appropriately substituted bromobenzofuran is converted to the corresponding aldehyde as described supra. This aldehyde is then reacted with 1-tert-butoxycarbonylcyclopropyllithium essentially as described by Haener et al. (Helvetica Chimica Acta, 69, 1655–65 (1986)) to provide the corresponding 1-tert-butoxycarbonyl-1-(benzofuryl)hydroxymethylcyclopropane. The alcohol is reduced to methylene by treating the corresponding acetate with samarium(II) iodide as described supra. The resulting tertbutyl ester is subjected to standard Curtius rearrangement conditions to provide the corresponding N-tert-butoxycarbonyl 1-amino-1-(benzofuryl)methylcyclopropane. This compound is deprotected by treatment with acid to provide the compounds of the present invention. If necessary or desired, the starting aldehyde may be reduced to the corresponding alcohol and then converted to the corresponding bromomethylbenzofuran. This reagent is then reacted with 1-tert-butoxycarbonylcyclopropyllithium essentially as described by Haener, to provide 1-tert-butoxycarbonyl-1-(benzofuryl)methylcyclopropane which is then subjected to the Curtius rearrangement/deprotection sequence described supra to provide the compounds of the present invention.
Workup
- customto provide the compounds of the present invention
Sources & evidence
- ORD record
- ord-0a471d22dee645e387a91639ef9c2c82
- Source dataset
- uspto-grants-2006_05
- Patent number
- US07045545B1
Reaction notes
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