Reaction #10172

Reaction equation

4-{[(4-hydroxymethyl-phenyl)-methyl-amino]-methyl}-benzoic acid methyl ester

dimethyl-amine

boron trichloride

sulfuric acid

NaCl water

→

9,10-dihydro-anthracene

Solvents

methylene chloride

Conditions

Workup

1. 1
   OtherMethylene chloride is removed
2. 2
   workup.WAITto stand at 40° C. over a period of 16 h
3. 3
   workup.ADDITIONThe resulting solution is poured
4. 4
   Otherinto crushed ice
5. 5
   ExtractionThe aqueous solution is extracted with methylene chloride (2×75 ml)
6. 6
   Dryingdried (Na2SO4)
7. 7
   Concentrationconcentrated

Procedure

To an ice cold solution of 4-{[(4-hydroxymethyl-phenyl)-methyl-amino]-methyl}-benzoic acid methyl ester (0.5 g, 1.8 mmol) and 3-isopropenyl-phenyl)-dimethyl-amine (0.31 g, 1.9 mmol) in methylene chloride (CH2Cl2, 25 mL)) is added dropwise a solution of boron trichloride (1 M BCl3 in CH2Cl2, 2 mL). The reaction mixture is allowed to stir overnight at room temperature cooled to −15° C. (NaCl/water) followed by dropwise addition of concentrated sulfuric acid (12 mL). Methylene chloride is removed and the mixture is allowed to stand at 40° C. over a period of 16 h. The resulting solution is poured into crushed ice and neutralized with 2 N sodium hydroxide. The aqueous solution is extracted with methylene chloride (2×75 ml), dried (Na2SO4) and concentrated giving the 9,10-dihydro-anthracene as a residue.

Source