تفاعل #55093

معادلة التفاعل

sodium chloroacetate

NaOH

thiourea

3,4-dimethoxybenzylchloride

→

3,4-Dimethoxybenzylthio-acetic acid

المردود 69.0%

المذيبات

water

water

ظروف التفاعل

المعالجة

1. 1
   أخرىequipped with a magnetic stirrer and a condenser
2. 2
   درجة الحرارةThe mixture is heated to 50°-60° C.
3. 3
   درجة الحرارةThe reactants are heated
4. 4
   درجة الحرارةto reflux
5. 5
   درجة الحرارةboiling is maintained for 15 mins
6. 6
   درجة الحرارةThereafter the mixture is cooled
7. 7
   درجة الحرارةHeating
8. 8
   درجة الحرارةunder reflux
9. 9
   درجة الحرارةthe mixture is cooled
10. 10
    درجة الحرارةThe whole is then heated
11. 11
    درجة الحرارةunder reflux for 30 minutes
12. 12
    درجة الحرارةcooled
13. 13
    ترشيحfiltered
14. 14
    أخرىAfter recrystallisation from toluene, 28.7 g of 3,4-dimethoxybenzylthio-acetic acid
15. 15
    أخرىare obtained

الإجراء التجريبي

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 3 N HCl. After recrystallisation from toluene, 28.7 g of 3,4-dimethoxybenzylthio-acetic acid are obtained. Yield: 69%. Instantaneous melting point: 94° C.

المصدر