反应详情

A solution of methyl 7-(2,2-dimethylpropionylamino)-3-oxochroman-8-carboxylate (Intermediate 10, 2.66 g) and glyoxylic acid monohydrate (0.802 g) in THF (6 mL) was heated in an open flask for 17 hours to give a viscous syrup which was diluted with ethanol (25 ml) and treated with hydrazine hydrate (0.471 g). The solution was stirred and heated at reflux for 45 minutes then cooled. The solid was collected by filtration to give methyl 7-(2,2-dimethylpropionylamino)-3-hydroxy-10H-9-oxa-1,2-diazaphenanthrene-8-carboxylate (1.13 g) as a sandy coloured solid.

1. customto give a viscous syrup which
2. temperatureheated
3. temperatureat reflux for 45 minutes
4. temperaturethen cooled
5. filtrationThe solid was collected by filtration