Sodium Hydroxide → HCID 178490208, Verbindung

Beteiligte Stoffe

Reaktionsschritte

13.07 g (0.172 mol) of thiourea and 86 ml of water are charged into a 1 liter three-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-dimethoxybenzyl chloride are added all at once. The mixture is heated under reflux and boiling is maintained for 15 minutes; the solution becomes limpid. Thereafter the solution is cooled and a solution of 27.52 g (0.688 mol) of NaOH in 43 ml of water is added dropwise at about 60° C. The mixture is again heated under reflux for 30 minutes, 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. Thereafter the whole is heated under reflux for 30 minutes, cooled and filtered and the filtrate 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.

Herkunft & Nachweise