反应详情

To a stirred solution of 6-tert-butyl 2-ethyl 5-(2,4-dichlorophenyl)-7-methylimidazo[1,2-a]pyrimidine-2,6-dicarboxylate (Example 54, Step 4, 3 g, 6.66 mmol) in THF (6 mL) and MeOH (2 mL) was added LiOH.H2O (0.42 g, 9.99 mmol) in H2O (2 mL). After 1 h, the reaction was quenched by 1N HCl till pH to 2. The organic volatiles were removed under reduced pressure and the residue was dissolved in EtOAc. The organic layer was washed with satd aq NH4Cl and brine prior to drying over MgSO4. Filtration, concentration under reduced pressure and recrystallization from 1:2 EtOAc/hexanes afforded 6-(tert-butoxycarbonyl)-5-(2,4-dichlorophenyl)-7-methylimidazo[1,2-a]pyrimidine-2-carboxylic acid (2.78 g, 90%) as a cream solid.

1. customthe reaction was quenched by 1N HCl till pH to 2
2. customThe organic volatiles were removed under reduced pressure
3. dissolutionthe residue was dissolved in EtOAc
4. washThe organic layer was washed with satd aq NH4Cl and brine
5. dry with materialto drying over MgSO4
6. filtrationFiltration, concentration
7. customunder reduced pressure and recrystallization from 1:2 EtOAc/hexanes