Potassium Carbonate → (+/-)-(5-Chloro-7-hydroxy-2,3-dihydro-1-benzofuran-2-yl)methyl 4-methylbenzenesulfonate
Reaction equation
[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([O:11][CH2:12][CH:13]2[CH2:17][C:16]3[CH:18]=[C:19]([Cl:24])[CH:20]=[C:21]([O:22]C)[C:15]=3[O:14]2)(=[O:10])=[O:9])=[CH:4][CH:3]=1.C(=O)([O-])[O-].[K+].[K+]>Br>[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([O:11][CH2:12][CH:13]2[CH2:17][C:16]3[CH:18]=[C:19]([Cl:24])[CH:20]=[C:21]([OH:22])[C:15]=3[O:14]2)(=[O:9])=[O:10])=[CH:4][CH:3]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Treatment of (±)-(5-chloro-7-methoxy-2,3-dihydro-1-benzofuran-2-yl)methyl 4-methylbenzenesulfonate (22.1 g, 0.06 mol) with hydrogen bromide (30 wt. % in acetic acid, 400 mL) followed by potassium carbonate (4.15 g, 0.03 mol) provided (±)-(5-chloro-7-hydroxy-2,3-dihydro-1-benzofuran-2-yl)methyl 4-methylbenzenesulfonate as a brown oil. Treatment of the phenyl with sodium hydride (3.2 g, 0.053 mol) and allyl bromide (6.4 g, 0.053 mol) generally according to the procedure described for Intermediate 37 afforded (±)-[7-(allyloxy)-5-chloro-2,3-dihydro-1-benzofuran-2-yl]methyl 4-methylbenzenesulfonate. Treatment of the allyl ether in refluxing mesitylene (250 mL) generally according to the procedure described for Intermediate 1 afforded 4.5 g (19%) of (±)-(6-allyl-5-chloro-7-hydroxy-2,3-dihydro-1-benzofuran-2-yl)methyl 4-methylbenzenesulfonate as a pale yellow solid. mp 128-131° C.; Anal. calcd. for C19H19ClO5S: C, 57.79; H, 4.85. Found: C, 58.28; H, 4.68.
Sources & evidence
- ORD record
- ord-5ae5ab8370e746e885f1b6f7524b6e8e
- Source dataset
- uspto-grants-2010_06
- Patent number
- US07728155B2
Reaction notes
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