反応 #56459

反応方程式

sodium chloroacetate

2,4-dichlorobenzylchloride

thiourea

NaOH

→

product

収率 88.7%

2,4Dichlorobenzylthio-acetic acid

収率 88.7%

溶媒

water

water

反応条件

後処理

1. 1
   温度The mixture is heated to 50°-60° C.
2. 2
   温度The mixture is heated
3. 3
   温度under reflux
4. 4
   温度boiling is maintained for 15 minutes
5. 5
   温度The mixture is cooled
6. 6
   温度The mixture is again heated
7. 7
   温度under reflux for 30 minutes
8. 8
   温度cooled
9. 9
   その他at 60°-70° C
10. 10
    温度The whole is then heated
11. 11
    温度under reflux for 30 minutes
12. 12
    温度cooled
13. 13
    ろ過filtered
14. 14
    その他the precipitate obtained
15. 15
    ろ過is filtered off the redissolved cold in dilute sodium bicarbonate solution
16. 16
    洗浄this solution is washed with methylene chloride
17. 17
    ろ過filtered

実験手順

15.2 g (0.2 mol) of thiourea in 100 ml of water are introduced into a 1 liter 3-necked flask. The mixture is heated to 50°-60° C. and 39.1 g (0.2 mol) of 2,4-dichlorobenzylchloride are introduced in a single operation. The mixture is heated under reflux and boiling is maintained for 15 minutes; the solution becomes limpid. The mixture is cooled and a solution of 32 g (0.8 mol) of NaOH in 50 ml of water is introduced dropwise at about 60° C. The mixture is again heated under reflux for 30 minutes, 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 NaHCO3) is introduced, dropwise, at 60°-70° C. The whole is then heated under reflux for 30 minutes, cooled, filtered and acidified with 3 N HCl; the precipitate obtained is filtered off the redissolved cold in dilute sodium bicarbonate solution, and this solution is washed with methylene chloride, filtered and again acidified. 41.7 g (yield: 83 %) of product are thus collected. Instantaneous melting point: 72°-73° C.

出典