Sulfuric acid magnesium salt (1:1) → 2-[4-(Benzyloxy)-3-bromobenzyl]azulene

Reaction equation

N1[CH2:5][CH2:4][CH2:3][CH2:2]1.S([O-])([O-])(=O)=O.[Mg+2].[CH2:12]([O:19][C:20]1[CH:25]=[CH:24][C:23]([CH2:26][C:27]([CH3:29])=O)=[CH:22][C:21]=1[Br:30])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1>C(OCC)C>[CH2:12]([O:19][C:20]1[CH:25]=[CH:24][C:23]([CH2:26][C:27]2[CH:5]=[C:4]3[C:2](=[CH:3][CH:4]=[CH:5][CH:2]=[CH:3]3)[CH:29]=2)=[CH:22][C:21]=1[Br:30])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

Procedure

Pyrrolidine (1.9 ml) and magnesium sulfate (2.74 g) were added to a solution of 1-[4-(benzyloxy)-3-bromophenyl]acetone (3.65 g) in diethyl ether (30 ml) and the mixture was stirred at room temperature for 12 hours. After filtration, the solvent was evaporated under reduced pressure. The resulting residue was dried under reduced pressure and dissolved in ethanol (30 ml). 2H-cyclohepta[b]furan-2-on (0.5 g) was added to the solution and the mixture was refluxed with heating for eight hours. The reaction mixture was concentrated. The resulting residue was purified by silica gel column chromatography (ethyl acetate-n-hexane) to obtain 2-[4-(benzyloxy)-3-bromobenzyl]azulene (0.84 g).