Reaktion #2374031

Reaktionsgleichung

Salicylamide

chloral

→

3,4-dihydro-2-trichloromethyl-2H-benzo[e]-[1,3]-oxazin-4-one

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe reaction mixture was cooled
2. 2
   Sonstigethe excess of chloral was evaporated under reduced pressure
3. 3
   workup.ADDITIONThe syrupy product was mixed with concentrated sulphuric acid (500 ml.)
4. 4
   Temperaturheated on a steam-bath for 1 hour
5. 5
   TemperaturThe mixture was cooled
6. 6
   workup.ADDITIONpoured
7. 7
   Sonstigeinto crushed ice (3 kg.)
8. 8
   Filtrationthe precipitated solid was filtered off
9. 9
   Sonstigetriturated with diethyl ether (300 ml.)
10. 10
    Filtrationfiltered again
11. 11
    Filtrationfiltered
12. 12
    Waschenwashed well with water
13. 13
    Sonstigedried
14. 14
    Sonstigecrystallised from ethanol (400 ml.)

Vorschrift

Salicylamide (40.0 g.) and anhydrous chloral (400 ml.) were heated together on a steam-bath for 3 hours, the reaction mixture was cooled, and the excess of chloral was evaporated under reduced pressure. The syrupy product was mixed with concentrated sulphuric acid (500 ml.) and heated on a steam-bath for 1 hour. The mixture was cooled and poured into crushed ice (3 kg.), and the precipitated solid was filtered off, triturated with diethyl ether (300 ml.) and filtered again. The solid product was stirred with water (1 l.), filtered, washed well with water, dried and crystallised from ethanol (400 ml.) to yield 3,4-dihydro-2-trichloromethyl-2H-benzo[e]-[1,3]-oxazin-4-one, m.p. 175°-177° C.

Quelle