تفاعل #75199

ord-d54ed9250267474ba28690bd9b62f4b9

الكواشف

لا شيء

المذيبات

ظروف التفاعل

درجة الحرارة
10°CELSIUS
الظروف التفصيلية
See reaction.notes.procedure_details.

المعالجة

  1. 1
    أخرىThe reaction is conducted in a 2 liter reaction flask
  2. 2
    أخرىequipped with thermometer, mechanical stirrer
  3. 3
    أخرىnear 10° C.
  4. 4
    ترشيحis 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
    أخرىto rise to 25° C.
  7. 7
    أخرىis removed)
  8. 8
    درجة الحرارةthe stirred mixture is warmed to 45° C
  9. 9
    ترشيحThe warm mixture is then filtered
  10. 10
    غسيلthe white crystalline product washed with water
  11. 11
    أخرىdried overnight at 60° C. in a circulating hot air oven
  12. 12
    workup.ADDITIONA sample is treated with concentrated ammonium hydroxide
  13. 13
    غسيلwashed with water
  14. 14
    أخرىdried

الإجراء التجريبي

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.

المصدر

DOI: 10.6084/m9.figshare.5104873.v1براءة الاختراع: US04175200uspto-grants-1979_11