反应详情

A mixture of 5-(2-thienyl)isoxazole (4.3 kg) and dimethylformamide dimethylacetal (6.1 kg; Lancaster) in toluene (12 L; Barton) is heated at reflux. As methanol forms it is removed by distillation. Solid forms from the reaction mixture. The reaction mixture is cooled and diluted with methyl-t-butyl ether (8 L; Van Waters). The precipitate is collected by filtration and washed with methyl-t-butyl ether (4 L). The solid is slurried with acetone (10 L; Batron) and hexanes (10 L; Mallinckrodt), then filtered and washed with hexanes (4 L). After drying in vacuo there is obtained 5.124 kg of α-[(dimethylamino)methylene]-β-oxo-2-thiophenepropane-nitrile (87% yield).

1. temperatureis heated
2. temperatureat reflux
3. customis removed by distillation
4. temperatureThe reaction mixture is cooled
5. additiondiluted with methyl-t-butyl ether (8 L; Van Waters)
6. filtrationThe precipitate is collected by filtration
7. washwashed with methyl-t-butyl ether (4 L)
8. filtrationfiltered
9. washwashed with hexanes (4 L)
10. customAfter drying in vacuo