Reaktion #54471

Reaktionsgleichung

3,5-dichloro-4-pyridinecarboxamide

p-chlorophenyl isocyanate

→

3,5-dichloro-N-[(4-chlorophenylamino)carbonyl]-4-pyridinecarboxamide

Lösungsmittel

xylene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe solution was heated
2. 2
   Temperaturunder reflux
3. 3
   SonstigeA small amount of impurity was removed
4. 4
   Filtrationby filtering the hot reaction mixture
5. 5
   TemperaturOn cooling in an ice water bath
6. 6
   Sonstigea solid precipitated
7. 7
   FiltrationThe precipitated product was collected by suction filtration
8. 8
   Waschenwashed with cold xylene
9. 9
   Sonstigedried in a vacuum oven at about 70° C
10. 10
    SonstigeThe dried crude product
11. 11
    Sonstigewas purified by recrystallization from 90 percent aqueous acetic acid

Vorschrift

A reaction vessel was charged with sixty-eight grams (0.36 mole) of 3,5-dichloro-4-pyridinecarboxamide, 55.5 grams (0.36 mole) of p-chlorophenyl isocyanate, and 1200 milliliters of xylene. The solution was heated under reflux with stirring for three hours. A small amount of impurity was removed by filtering the hot reaction mixture. On cooling in an ice water bath, a solid precipitated. The precipitated product was collected by suction filtration, washed with cold xylene and dried in a vacuum oven at about 70° C. The dried crude product was purified by recrystallization from 90 percent aqueous acetic acid. The yield was 81 grams (66 percent of theoretical) of white needles melting at 225°-227° C. Nuclear magnetic resonance spectral data confirmed the structure as being ##STR12##

Quelle