Reaction #1531300

Reaction equation

2,5-dibromo-3-methyl-pyridine

piperazine-1-carboxylic acid tert-butyl ester

DIEA

→

title compound

4-(5-bromo-3-methyl-pyridin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester

Solvents

DMA

Conditions

Workup

1. 1
   OtherPartition the dark brown reaction mixture between water and EtOAc
2. 2
   WashWash the EtOAc layer with water (1×) and brine (1×)
3. 3
   Dryingdry (Na2SO4)
4. 4
   Concentrationconcentrate under reduced pressure
5. 5
   Otherto give the crude product
6. 6
   OtherPurify by flash chromatography
7. 7
   Washeluting with 9:1 hexanes
8. 8
   TemperatureEtOAc, increasing to 3:1 hexanes

Procedure

Heat a solution of 2,5-dibromo-3-methyl-pyridine (Chontech Inc.) (12.6 g, 50.3 mmol), piperazine-1-carboxylic acid tert-butyl ester (11.7 g, 62.9 mmol) and DIEA (13.3 g, 102.0 mmol) in DMA at 130° C. for 36 h. Partition the dark brown reaction mixture between water and EtOAc. Wash the EtOAc layer with water (1×) and brine (1×), dry (Na2SO4) and concentrate under reduced pressure to give the crude product. Purify by flash chromatography, eluting with 9:1 hexanes:EtOAc, increasing to 3:1 hexanes:EtOAc to provide the title compound as a solid.

Source