Reaction #4393

Reaction equation

8-(2-chlorobenzyloxy)-2-methylimidazo[1,2-a]pyridine

formaldehyde

dimethylamine

→

8-(2-chlorobenzyloxy)-3-dimethylaminomethyl-2-methylimidazo[1,2-a]pyridine

Yield 85.4%

Solvents

acetic acid

Conditions

Workup

1. 1
   Temperaturecooling over a period of 10 minutes
2. 2
   TemperatureThe mixture was heated at 50°-55° C. for 2 hours
3. 3
   Otherevaporated in vacuo
4. 4
   Extractionextracted with methylene chloride
5. 5
   WashThe extract was washed with water
6. 6
   Dryingdried over magnesium sulfate
7. 7
   Otherevaporated in vacuo
8. 8
   OtherThe residual solid was recrystallized from a mixture of diethyl ether and n-hexane

Procedure

To a solution of 37% aqueous formaldehyde (2.38 g) in acetic acid (38 ml) was added dropwise 50% aqueous dimethylamine (2.63 g) with ice-cooling over a period of 10 minutes and the mixture was stirred for an additional 10 minutes. The mixture was heated at 50°-55° C. for 2 hours after an addition of 8-(2-chlorobenzyloxy)-2-methylimidazo[1,2-a]pyridine (7.6 g) thereto and then evaporated in vacuo. The residue was basified with aqueous sodium hydroxide and extracted with methylene chloride. The extract was washed with water, dried over magnesium sulfate and evaporated in vacuo. The residual solid was recrystallized from a mixture of diethyl ether and n-hexane to give 8-(2-chlorobenzyloxy)-3-dimethylaminomethyl-2-methylimidazo[1,2-a]pyridine (7.85 g).

Source