Réaction #156739

Équation de réaction

sodium

methoxyacetic acid

thiosemicarbazide

phosphorous oxychloride

→

5-(methoxymethyl)-1,3,4-thiadiazol-2-amine

Rendement 81.0%

Solvants

water

dioxane

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONis added
2. 2
   ExtractionAfter extraction EtOAc/iPrOH (9/1) and evaporation under vacuum
3. 3
   Autrethe residue is recrystallized from MeTHF/iPrOH

Mode opératoire

To a suspension of thiosemicarbazide a24 (40 g, 0.44 mol, 1 eq) in dioxane (400 ml) at room temperature is added methoxyacetic acid (39.56 g, 0.44 mol, 1 eq) in one portion, and the reaction mixture is heated at 80° C. then phosphorous oxychloride (67.54 g, 0.44 mol, 1 eq) is carefully added over 1.5 hours. After reaction completion (4 hours), water is added and the solution is neutralised to pH=6-7 with sodium hydroxyde pellets. After extraction EtOAc/iPrOH (9/1) and evaporation under vacuum, the residue is recrystallized from MeTHF/iPrOH to afford 51 g of pure 5-(methoxymethyl)-1,3,4-thiadiazol-2-amine a25.

Source