Reaktion #1808237

Reaktionsgleichung

hydrochloric acid

hydrogen peroxide

4-methyl-5-trifluoromethyl-2,4-dihydro-3H-1,2,4-triazole-3-thione

sodium hydrogen sulphite

→

sodium 4-methyl-5-trifluoromethyl-4H-1,2,4-triazole-3-sulphonate

Ausbeute 73.0%

Lösungsmittel

sodium hydroxide

Reaktionsbedingungen

Aufarbeitung

1. 1
   WaschenIt is subsequently washed with ethyl acetate
2. 2
   Einengenthe aqueous solution is then concentrated under a water pump vacuum to approximately 200 ml
3. 3
   SonstigeThe solid obtained
4. 4
   Temperaturduring cooling
5. 5
   Sonstigeis isolated by filtration

Vorschrift

25 g (0.14 mol) of 4-methyl-5-trifluoromethyl-2,4-dihydro-3H-1,2,4-triazole-3-thione are dissolved in 250 ml of 2.5-molar sodium hydroxide solution, and 46.5 g of a 35% strength hydrogen peroxide solution (0.48 mol of H2O2) are added in the course of 60 minutes at a reaction temperature of 40° C. to 45° C. (external cooling). The mixture is stirred for 6 hours at 40° C.; excess oxidant is then decomposed using sodium hydrogen sulphite, and the solution is acidified with 18-molar hydrochloric acid to a pH of 2. It is subsequently washed with ethyl acetate, and the aqueous solution is then concentrated under a water pump vacuum to approximately 200 ml. The solid obtained during cooling is isolated by filtration. 25 g (73% of theory) of sodium 4-methyl-5-trifluoromethyl-4H-1,2,4-triazole-3-sulphonate are obtained.

Quelle