Reaktion #5916

Reaktionsgleichung

3-amino-5-(2-furyl)-1,2,4-triazole

dimethyl N-cyanodithioiminocarbonate

→

7-amino-2-(2-furyl)-5-methylthio-[1,2,4]triazolo[1,5-a][1,3,5]triazine

Ausbeute 20.3%

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter cooling
2. 2
   Sonstigethe resulting solid was purified by column chromatography on silica (600 g)
3. 3
   Wascheneluting with an increasing amount of ethyl acetate in dichloromethane (5-10% v/v)

Vorschrift

An intimate mixture of 3-amino-5-(2-furyl)-1,2,4-triazole (33.0 g) and dimethyl N-cyanodithioiminocarbonate (33.0 g) was heated at 170° C. for 1 hour, under a slow stream of argon. After cooling, the resulting solid was purified by column chromatography on silica (600 g) eluting with an increasing amount of ethyl acetate in dichloromethane (5-10% v/v) to give 7-amino-2-(2-furyl)-5-methylthio-[1,2,4]triazolo[1,5-a][1,3,5]triazine as a colourless solid (11.1 g), essentially pure by TLC, which was used without further purification. [A small amount of the above solid was recrystallised from ethanol to give, crystals, m.p. 238°-240° C.; microanalysis, found: C,44.0; H,3.3; N,33.7; C9H8N6SO. 0.05C2H5OH requires C,43.6; H,3.3; N,33.6; NMR 1.05 and 3.4 (t+q, ethanol of crystallisation), 2.5 (s, 3H, CH3S-- ), 6.7(dd, 1H, furyl-4H), 7.2(d, 1H, furyl-3H), 7.7(d, 1H, furyl-5H) 8.7-9.0(br d, 2H, NH2); m/e 248 (M+).

Quelle