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5-Amino-2-methoxypyridine (55.0 g, 0.44 mole) in methanol (1000 mL) with methyl propiolate (40 mL, 0.44 mole) was stirred for 48 hours, then evaporated and the product purified by chromatography on-silica gel (dichloromethane) followed by recrystallization from dichloromethane-hexane (44.6 g, 48%). The unsaturated ester (10.5 g, 0.05 mole) 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 diethyl ether. The precipitate was filtered to give a solid (6.26g, 70%).

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