Hydrazine → 2-Ethyl-6-methoxy-1-benzofuran
Reaction equation
CCC1OC2C=C(O)C=CC=2C=1C(C1C=C(Br)C(O)=C(Br)C=1)=O.[C:24]([C:27]1[O:28][C:29]2[CH:35]=[C:34]([O:36][CH3:37])[CH:33]=[CH:32][C:30]=2[CH:31]=1)(=O)[CH3:25].NN>>[CH2:24]([C:27]1[O:28][C:29]2[CH:35]=[C:34]([O:36][CH3:37])[CH:33]=[CH:32][C:30]=2[CH:31]=1)[CH3:25]Participants
Procedure
As for preferred example of producing 6-hydroxybenzbromarone according to the present invention, it can be produced as follows. That is, for example, 2-acetyl-6-methoxy-benzofuran is reduced using hydrazine to obtain 2-ethyl-6-methoxy-benzofuran, which is then reacted with acid chloride of 4-methoxy-benzoic acid under the presence of tin tetrachloride to yield 2-ethyl-6-methoxy-3-(p-methoxy-benzoyl)-benzofuran. And then methoxy group of benzoyl group is selectively deprotected under the presence of ethane thiol sodium salt to yield 2-ethyl-6-methoxy-3-(p-hydroxy-benzoyl)-benzofuran, which is then brominated by sodium-N-bromosuccinimide under the presence of dimethyl sulfide to obtain 2-ethyl-6-methoxy-3-(3′,5′-dibromo-4′-hydroxy-benzoyl)-benzofuran, and then methoxy group at sixth place is deprotected under the presence of aluminum chloride.
Sources & evidence
- ORD record
- ord-16c4e748b19242e8a8ee23d65ac6acfe
- Source dataset
- uspto-grants-2009_04
- Patent number
- US07521570B2
Reaction notes
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