Reaction #82798

Reaction equation

1-amino-1-(5-chloro-2-pyridyl)-2-(1H-imidazol-1-yl)ethane

triethylamine

(1S)(-)-camphanic acid chloride

→

1-[(1S)-Camphanoyl]amino-1-(5-chloro-2-pyridyl)-2-(1H-imidazol-1-yl)ethane

Solvents

dichloromethane

Conditions

Workup

1. 1
   Temperaturecooled to -79°
2. 2
   Otherdoes not exceed -74°
3. 3
   workup.STIRRINGStirring
4. 4
   workup.ADDITIONis poured onto ice-water
5. 5
   Extractionextracted three times with dichloromethane
6. 6
   Washwashed with brine
7. 7
   DryingAfter drying with sodium sulfate the solvent
8. 8
   Otheris evaporated
9. 9
   workup.ADDITIONA mixture of the two diastereomeric amides
10. 10
    Otheris obtained which
11. 11
    Otheris separated by chromatography over silica gel (dichloromethane/methanol/heptane=10/1/5)
12. 12
    OtherThe two compounds are obtained as white crystals

Procedure

To a solution of 0.38 g of 1-amino-1-(5-chloro-2-pyridyl)-2-(1H-imidazol-1-yl)ethane (racemic compound, see A) above) in 4 ml of dry dichloromethane is added 0.26 g (0.36 ml) of triethylamine. The mixture is stirred and cooled to -79°. Then 0.44 g of (1S)(-)-camphanic acid chloride are added in such a way that the temperature does not exceed -74°. Stirring is continued for additionally 90 minutes without further cooling. For working up the mixture is poured onto ice-water, extracted three times with dichloromethane and washed with brine. After drying with sodium sulfate the solvent is evaporated. A mixture of the two diastereomeric amides is obtained which is separated by chromatography over silica gel (dichloromethane/methanol/heptane=10/1/5). The two compounds are obtained as white crystals:

Source