反应详情

5-Amino-2-methoxypyridine (55 g, 0.44 mol) in methanol (1000 ml) with methyl propiolate (40 ml, 0.44 mol) was stirred for 48 hours, then evaporated and the product purified by chromatography on silica gel (dichloromethane) followed by recrystallisation from dichloromethane-hexane (44.6 g, 48%). The unsaturated ester (10.5 g, 0.05 mol) in warm Dowtherm A (50 ml) was added over 3 minutes to refluxing Dowtherm A, and after a further 20 minutes at reflux the mixture was cooled and poured into ether. The precipate was filtered to give a white solid (6.26 g, 70%).

1. customevaporated
2. customthe product purified by chromatography on silica gel (dichloromethane)
3. customfollowed by recrystallisation from dichloromethane-hexane (44.6 g, 48%)
4. temperatureafter a further 20 minutes at reflux the mixture
5. temperaturewas cooled
6. filtrationThe precipate was filtered