反应详情

The pyrazinone 18-6 (900 mg) was heated at reflux in trifluoroacetic acid (20 mL) for 7 h. The volatiles were removed in vacuo and the residue was azeotroped with CH2Cl2, then EtOAc then MeOH. MeOH was added to the residue and the solution filtered to remove impurities. Removal of the methanol then afforded the title compound 18-7 which was used as such:

1. customThe volatiles were removed in vacuo
2. customthe residue was azeotroped with CH2Cl2
3. additionMeOH was added to the residue
4. filtrationthe solution filtered
5. customto remove impurities
6. customRemoval of the methanol