反应详情

To a solution of 4-methoxy-4-oxobutanoic acid (9.7 g, 73.5 mmol) in toluene (368 mL) was added diphenylphosphoryl azide (20.2 g, 73.5 mmol) followed by TEA (12.4 g, 122.7 mmol). The reaction was stirred at RT for 30 min then 5-amino-2-chloroisonicotinic acid (8.47 g, 49 mmol) was added. The reaction was heated at reflux for 6 h, cooled to RT then diluted with EA (300 mL). The mixture was washed with brine (300 mL) and out of the organic layer precipitated a solid which was filtered. The separated aqueous layer was acidified to PH 5 by adding aq. 2N HCl and a precipitate formed. The solid was filtered and combined with the organic layer solid. The combined solids were dried to give 2-chloro-5-(3-(3-methoxy-3-oxopropyl)ureido) isonicotinic acid (26 g, >100% yield) as brown semi-solid. LCMS: MH+ 302 MH+ and TR=2.752 min. Used without further purification.

1. temperatureThe reaction was heated
2. temperatureat reflux for 6 h
3. temperaturecooled to RT
4. washThe mixture was washed with brine (300 mL) and out of the organic layer
5. customprecipitated a solid which
6. filtrationwas filtered
7. additionby adding aq. 2N HCl
8. customa precipitate formed
9. filtrationThe solid was filtered
10. customThe combined solids were dried