Reaction #2834

Reaction equation

Phosphorus oxychloride

isonicotinic acid N-oxide

→

2-chloroisonicotinic acid

Conditions

Workup

1. 1
   workup.STIRRINGwith vigorously stirring
2. 2
   Otherto precipitate light yellow crystals
3. 3
   FiltrationThe resulting crystals were filtered out
4. 4
   Washwashed with water
5. 5
   Otherdried by vacuum
6. 6
   Temperatureheating (60° C.)
7. 7
   Otherto obtain the above-captioned compound ([9]-(92)-467) (37.845 g)

Procedure

Phosphorus oxychloride (220.7 g) was added to isonicotinic acid N-oxide (50.064 g), and the mixture was stirred on an oil bath at 120° C. for 7 hours. The reaction mixture was slowly poured into ice water with vigorously stirring to precipitate light yellow crystals. The mixture was adjusted to approximately pH 4 with 4N NaOH aqueous solution. The resulting crystals were filtered out, washed with water, and dried by vacuum heating (60° C.) to obtain the above-captioned compound ([9]-(92)-467) (37.845 g).

Source