Reaktion #88424

Reaktionsgleichung

Ethoxycarbonyl isothiocyanate

2-aminopyridine-4-carboxylic acid methyl ester

hydroxyamine hydrochloride

diisopropylethylamine

→

title compound

methyl 2-amino-[1,2,4]triazolo[1,5-a]pyridine-7-carboxylate

Lösungsmittel

ethanol

methanol

1,4-dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenwas then concentrated under reduced pressure
2. 2
   Sonstigeto obtain a crude product
3. 3
   SonstigeThe obtained crude product
4. 4
   workup.STIRRINGthe reaction solution was stirred at room temperature for 67 hours, at 60° C. for 5 hours
5. 5
   workup.WAITagain, at room temperature for 20 hours
6. 6
   SonstigeThereafter, the generated solid was collected
7. 7
   Waschenit was washed with ethanol (30 ml)
8. 8
   Sonstigewas then dried

Vorschrift

Ethoxycarbonyl isothiocyanate (9.0 g) was added to a 1,4-dioxane (100 ml) suspension of 2-aminopyridine-4-carboxylic acid methyl ester (10 g) at an internal temperature of 19° C. to 23° C. over 20 minutes. The obtained mixture was stirred for 90 minutes at the same temperature as described above, and was then concentrated under reduced pressure to obtain a crude product. The obtained crude product was added to a mixed suspension of methanol (70 ml) and ethanol (70 ml) containing hydroxyamine hydrochloride (22.8 g) and diisopropylethylamine (34 ml), and thereafter, the reaction solution was stirred at room temperature for 67 hours, at 60° C. for 5 hours, and again, at room temperature for 20 hours. Thereafter, the generated solid was collected, and it was washed with ethanol (30 ml) and was then dried, so as to obtain the title compound (11.3 g) in the form of a white solid.

Quelle