Reaktion #86876

Reaktionsgleichung

2-(thiophen-3-yl)acetic acid

ethyl 2-amino-2-(hydroxyimino)acetate

N,N diisopropylethylamine

oxalyl chloride

→

ethyl 5-(thiophen-3-ylmethyl)-1,2,4-oxadiazole-3-carboxylate

Ausbeute 38.1%

Lösungsmittel

dichloromethane

dichloromethane

pyridine

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThis compound was prepared
2. 2
   SonstigeThe crude material was purified by flash chromatography on silica (eluent 20 to 100% ethyl acetate in heptane)

Vorschrift

This compound was prepared according to general method 2 with (step I) 2-(thiophen-3-yl)acetic acid (0.568 g; 3.78 mmol), oxalyl chloride (0.352 mL; 4.16 mmol) in dichloromethane (12 mL) with few drops of DMF; (step II) ethyl 2-amino-2-(hydroxyimino)acetate (0.5 g; 3.78 mmol); N,N diisopropylethylamine (1.05 mL; 6.06 mmol) in dichloromethane (6 mL) and (step III) pyridine (18 mL). The crude material was purified by flash chromatography on silica (eluent 20 to 100% ethyl acetate in heptane) to yield 0.343 g (38%) of ethyl 5-(thiophen-3-ylmethyl)-1,2,4-oxadiazole-3-carboxylate as a yellow solid.

Quelle