反応 #56462

反応方程式

sodium chloroacetate

NaOH

thiourea

3,4-dimethoxybenzylchloride

→

3,4-Dimethoxybenzylthio-acetic acid

収率 69.0%

溶媒

water

water

反応条件

後処理

1. 1
   その他equipped with a magnetic stirrer and a condenser
2. 2
   温度The mixture is heated to 50°-60° C.
3. 3
   温度The reactants are heated
4. 4
   温度to reflux
5. 5
   温度boiling is maintained for 15 mins
6. 6
   温度Thereafter the mixture is cooled
7. 7
   温度Heating
8. 8
   温度under reflux
9. 9
   温度the mixture is cooled
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After recrystallisation from toluene, 28.7 g of 3,4-dimethoxybenzylthio-acetic acid
15. 15
    その他are obtained

実験手順

13.07 g (0.172 mol) of thiourea and 86 ml of water are introduced into a 1 liter 3-necked flask equipped with a magnetic stirrer and a condenser. The mixture is heated to 50°-60° C. and 32 g (0.172 mol) of 3,4-dimethoxybenzylchloride are added in a single operation. The reactants are heated to reflux and boiling is maintained for 15 mins; the solution becomes limpid. Thereafter the mixture is cooled and a solution of 27.52 g (0.688 mol) of NaOH in 43 ml of water is introduced dropwise at about 60° C. Heating under reflux is again carried out for 30 minutes, the mixture is cooled and a solution of sodium chloroacetate (obtained by neutralising 22.76 g of chloroacetic acid in 172 ml of water with 20.23 g of NaHCO3) is added dropwise at 60°-70° C. The whole is then heated under reflux for 30 minutes, cooled, filtered and then acidified with 3N HCl. After recrystallisation from toluene, 28.7 g of 3,4-dimethoxybenzylthio-acetic acid are obtained. Yield: 69%. Instantaneous melting point: 94° C.

出典