反应详情

2-Acetyl-3,5-dimethylpyrazine (2.65 g), hydroxylamine hydrochloride (2.5 g) and sodium acetate trihydrate (3.5 g) were refluxed in methanol (50 ml) for 1 hour. The reaction mixture was concentrated, diluted with water (75 ml) and extracted with ethyl acetate. The combined extracts were dried and concentrated to give an oil which was triturated with ether and 60°-80° C. petrol to give 3,5-dimethyl-2-(1-hydroximinoethyl)pyrazine (2.54 g, 87% yield) as a white solid (m.p. 85°-89° C.) and as a 1:1 mixture of (E/Z) isomers.

1. concentrationThe reaction mixture was concentrated
2. additiondiluted with water (75 ml)
3. extractionextracted with ethyl acetate
4. customThe combined extracts were dried
5. concentrationconcentrated
6. customto give an oil which
7. customwas triturated with ether and 60°-80° C. petrol