반응 #543536

반응 방정식

5-chloro-2-hydroxybenzamide

pyridine

hydrochloric acid

Ethyl chloroformate

→

6-chloro-2H-1,3-benzoxazine-2,4(3H)-dione

수율 85.3%

용매

water

acetonitrile

반응 조건

후처리

1. 1
   workup.DISTILLATIONthe volatiles were distilled off (43 ml)
2. 2
   온도The reaction was cooled to room temperature
3. 3
   기타to form
4. 4
   여과The resulting solid was filtered
5. 5
   기타recrystallized in hot ethanol

실험 절차

A solution of 10 g of 5-chloro-2-hydroxybenzamide (58.0 mmol), pyridine (22 ml) and acetonitrile (25 ml) was stirred in an ice bath. Ethyl chloroformate (6.1 ml, 0.0638 mol) was added dropwise. The pink solution was stirred for 30 minutes at <10° C. The ice bath was replaced with an oil bath. The reaction mixture was heated to 95° C. and the volatiles were distilled off (43 ml). The reaction was cooled to room temperature, causing a white solid to form. The mixture was poured into water (100 ml) and acidified with concentrated aqueous hydrochloric acid. The resulting solid was filtered and recrystallized in hot ethanol to give 9.77 g of 6-chloro-2H-1,3-benzoxazine-2,4(3H)-dione.

출처