反应详情

2-(2-Hydroxy-1-methoxycarbonyl-vinyl)-1-methyl-1H-pyrrole-3-carboxylic acid methyl ester (12.46 g), ammonium acetate (20.09 g) and methanol (200 ml) were refluxed under argon for 5 hours. After cooling the solvent was evaporated and the residue dissolved in ethyl acetate and washed with water, the aqueous was separated and extracted three times with ethyl acetate. The combined organics were washed with saturated brine solution and the organic layer was dried (MgSO4), filtered and evaporated. The residue was then taken up in the minimum amount of ethyl acetate and a precipitate formed which was filtered off to yield the title compound as an off-white solid (3.3 g). The filtrate was evaporated to yield the title compound as a brown solid (6.36 g). Both were taken through without further purification.

1. temperatureAfter cooling the solvent
2. customwas evaporated
3. dissolutionthe residue dissolved in ethyl acetate
4. washwashed with water
5. customthe aqueous was separated
6. extractionextracted three times with ethyl acetate
7. washThe combined organics were washed with saturated brine solution
8. dry with materialthe organic layer was dried (MgSO4)
9. filtrationfiltered
10. customevaporated
11. customa precipitate formed which
12. filtrationwas filtered off