Réaction #75199

Équation de réaction

isopropyl chloroformate

p-toluenesulfonyl semicarbazide

KOH

→

1-p-Toluenesulfonyl-1-Carbisopropoxy-2-Carbamyl Hydrazine

Solvants

water

water

Conditions de réaction

Traitement

1. 1
   AutreThe reaction is conducted in a 2 liter reaction flask
2. 2
   Autreequipped with thermometer, mechanical stirrer
3. 3
   Autrenear 10° C.
4. 4
   Filtrationis filtered from the p-toluenesultonyl semicarbazide salt solution)
5. 5
   workup.STIRRINGThe reaction mixture in the flask is stirred for an additional hour as the temperature
6. 6
   Autreto rise to 25° C.
7. 7
   Autreis removed)
8. 8
   Températurethe stirred mixture is warmed to 45° C
9. 9
   FiltrationThe warm mixture is then filtered
10. 10
    Lavagethe white crystalline product washed with water
11. 11
    Autredried overnight at 60° C. in a circulating hot air oven
12. 12
    workup.ADDITIONA sample is treated with concentrated ammonium hydroxide
13. 13
    Lavagewashed with water
14. 14
    Autredried

Mode opératoire

The reaction is conducted in a 2 liter reaction flask equipped with thermometer, mechanical stirrer, dropping funnel, and an ice-water bath. 400 ml. water is placed in the flask and cooled to 10° C. Then 73.4 g. (0.6 mole) of isopropyl chloroformate is added. The mixture is stirred at 10° C. as a filtered solution of 114.5 g. (0.5 moles) of p-toluenesulfonyl semicarbazide in a mixture of 36.5 g. (0.55 mole) of KOH in 400 ml. of water is dropped in over the period of an hour, keeping the temperature near 10° C. (A small amount (7.5 g.) of caustic insoluble solid is filtered from the p-toluenesultonyl semicarbazide salt solution). The reaction mixture in the flask is stirred for an additional hour as the temperature is allowed to rise to 25° C. (the cooling bath is removed). A heating mantle is applied and the stirred mixture is warmed to 45° C. The warm mixture is then filtered and the white crystalline product washed with water and dried overnight at 60° C. in a circulating hot air oven. Yield 145 g. (98.4%). m.p. 210°-212° C. A sample is treated with concentrated ammonium hydroxide, washed with water and dried. m.p.=211°-213° C.

Source