Reaction #475678

Reaction equation

4-Amino-3-fluorophenol

potassium tert-butoxide

sodium hydroxide

4-Chloropyridine-2-carboxamide

→

title compound

Yield 90.2%

4-(4-Amino-3-fluorophenoxy)pyridine

Yield 90.2%

Solvents

dimethyl sulfoxide

Conditions

Workup

1. 1
   workup.ADDITIONwas added at room temperature
2. 2
   workup.STIRRINGby stirring in an oil bath at 80° C. (external temperature) under a nitrogen stream for 50 minutes
3. 3
   workup.STIRRINGby stirring
4. 4
   FiltrationThe precipitated solid was collected by filtration
5. 5
   Washwashed with water
6. 6
   OtherThe residue was dried under aeration
7. 7
   Otherdried by hot air at 100° C.

Procedure

4-Amino-3-fluorophenol (5.7 g) was dissolved in dimethyl sulfoxide (57 ml) under a nitrogen stream, potassium tert-butoxide (5.6 g) was added at room temperature, and the reaction mixture was stirred for 15 minutes. 4-Chloropyridine-2-carboxamide (5.0 g) was added to the reaction mixture, followed by stirring in an oil bath at 80° C. (external temperature) under a nitrogen stream for 50 minutes. The reaction mixture was allowed to cool down to room temperature. A 1N aqueous solution of sodium hydroxide (85.5 ml) was added to the reaction mixture, followed by stirring. The precipitated solid was collected by filtration and washed with water. The residue was dried under aeration and then dried by hot air at 100° C. to give the title compound (5.88 g, 74.3%) as pale brown powder.

Source