반응 #56457
ord-90b6abbdc7c44f2195eb796835879a6d
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후처리
- 1기타equipped with a magnetic stirrer, a condenser
- 2온도The mixture is heated
- 3온도to reflux
- 4온도boiling is maintained for about 15 minutes
- 5온도Thereafter the mixture is cooled
- 6온도The whole is heated
- 7온도under reflux for about 30 minutes
- 8온도cooled
- 9온도Thereafter the whole is heated
- 10온도under reflux for 30 minutes
- 11온도cooled
- 12기타the oil obtained
- 13세척the solution is washed with a dilute solution of sodium bicarbonate
- 14여과filtered over charcoal
- 15기타thus precipitates
- 16여과is filtered off
실험 절차
A solution of 15.2 g (0.2 mol) of thiourea in 100 ml of water is introduced into a 1 liter 3-necked flask equipped with a magnetic stirrer, a condenser and dropping funnel, and 28.9 g (0.2 mol) of p-fluorobenzylchloride are introduced, at 50°-60° C., in a single operation. The mixture is heated to reflux and boiling is maintained for about 15 minutes; the solution becomes limpid. Thereafter the mixture is cooled and a solution of 32 g (0.8 mol) of NaOH in water is added dropwise at about 60° C. The whole is heated under reflux for about 30 minutes and cooled and a solution of about 0.28 mol of sodium chloroacetate (obtained by neutralising 26.46 g of chloroacetic acid in 200 ml of water with 23.52 g of sodium bicarbonate) is added dropwise at 60°-70° C. Thereafter the whole is heated under reflux for 30 minutes, and then cooled. The mixture is acidified with 3N HCl, the oil obtained is taken up in methylene chloride, the solution is washed with a dilute solution of sodium bicarbonate, filtered over charcoal and acidified once more with 3 N HCl and p-flourobenzylthioacetic acid thus precipitates and is filtered off. After recrystallisation from cyclohexane, 33.4 g (yield: 83%) of the said acid are collected. Instantaneous melting point: 68°-69° C.