Reaction #5387

Reaction equation

2-methyl-3-(4'-methoxycarbonyl-3'-methoxyphenyl)-1-naphthol

boron trichloride

→

2-methyl-3-(4'-methoxycarbonyl-3'-hydroxyphenyl)-1-naphthol

Yield 71.7%

Solvents

methylene chloride

methylene chloride

Conditions

Workup

1. 1
   TemperatureTo a cooled
2. 2
   workup.ADDITIONwas added, dropwise over 10 minutes
3. 3
   Otherquenched with 25 mL of methanol
4. 4
   WashThe solution was washed with 3×40 mL of 1 N hydrochloric acid
5. 5
   DryingThe organic layer was dried over magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   Concentrationconcentrated
8. 8
   OtherThe residual oil was purified by flash chromatography (2:1 methylene chloride:hexane as eluent)

Procedure

To a cooled (-78° C.) suspension of 7.0 g of 2-methyl-3-(4'-methoxycarbonyl-3'-methoxyphenyl)-1-naphthol in 100 mL of methylene chloride was added, dropwise over 10 minutes, 26 mL of 1 M boron trichloride in methylene chloride. The resulting mixture was stirred overnight at 25° C. and then quenched with 25 mL of methanol. The solution was washed with 3×40 mL of 1 N hydrochloric acid and then 2×50 mL of saturated sodium bicarbonate. The organic layer was dried over magnesium sulfate, filtered and concentrated. The residual oil was purified by flash chromatography (2:1 methylene chloride:hexane as eluent) to give 4.8 g of 2-methyl-3-(4'-methoxycarbonyl-3'-hydroxyphenyl)-1-naphthol as a white solid.

Source