Reaction #5452

Reaction equation

6-bromo-5-chlorovanillin

1.8-diazabicyclo[5,4,0]-7-undecene

methyl iodide

diisopropylethylamine

methyl iodide

→

title compound

Yield 71.0%

2-Bromo-3-chloro-4,5-dimethoxybenzaldehyde

Yield 71.0%

Solvents

acetonitrile

Conditions

Workup

1. 1
   Temperatureunder cooling with ice
2. 2
   Temperatureunder cooling with ice
3. 3
   workup.STIRRINGthe mixture was stirred for 20 hours at room temperature
4. 4
   workup.DISTILLATIONAfter distilled off the solvent, 200 ml of dichloromethane
5. 5
   workup.ADDITIONwere added to the residue, which
6. 6
   Washwas washed with water
7. 7
   DryingAfter dried over anhydrous magnesium sulfate
8. 8
   Otherthe concentrated residue was purified by means of silica gel column chromatography (hexane-AcOEt 5:1)

Procedure

Into 50 ml of acetonitrile were suspended 5.39 g (20.3 mmol), of 6-bromo-5-chlorovanillin, and 3.04 ml (20.3 mmol) of 1.8-diazabicyclo[5,4,0]-7-undecene and 2.53 ml (40.6 mmol) of methyl iodide were added dropwise under cooling with ice. After stirred for 5 hours at room temperature, 3.9 ml (22.33 mmol) if diisopropylethylamine and 2.53 ml (40.6 mmol) of methyl iodide were added under cooling with ice and the mixture was stirred for 20 hours at room temperature. After distilled off the solvent, 200 ml of dichloromethane were added to the residue, which was washed with water. After dried over anhydrous magnesium sulfate, the concentrated residue was purified by means of silica gel column chromatography (hexane-AcOEt 5:1) to obtain 4.04 g (yield 71%) of title compound as colorless needle-like crystals.

Source