Reaction #531820

Reaction equation

potassium carbonate

2,3-dichloropyridine

3-chloropyrazole

product

3-chloropyrazole

→

title product

3-chloro-2-(3-chloro-1H-pyrazol-1-yl)pyridine

Solvents

N,N-dimethylformamide

Conditions

Workup

1. 1
   TemperatureThe reaction mixture was cooled to room temperature
2. 2
   FiltrationThe precipitated solids were filtered
3. 3
   Washwashed with water
4. 4
   FiltrationThe solid filter cake
5. 5
   Dryingdried over magnesium sulfate
6. 6
   Concentrationconcentrated
7. 7
   OtherThe crude solid was chromatographed on silica gel using 20% ethyl acetate/hexane as eluent

Procedure

To a mixture of 2,3-dichloropyridine (92.60 g, 0.629 mol) and 3-chloropyrazole (i.e. the product of Step B) (64.44 g, 0.629 mol) in N,N-dimethylformamide (400 mL) was added potassium carbonate (147.78 g, 1.06 mol), and the reaction mixture was then heated to 100° C. for 36 hours. The reaction mixture was cooled to room temperature and slowly poured into ice water. The precipitated solids were filtered and washed with water. The solid filter cake was taken up in ethyl acetate, dried over magnesium sulfate and concentrated. The crude solid was chromatographed on silica gel using 20% ethyl acetate/hexane as eluent to afford 39.75 g of the title product as a white solid.

Source