反应详情

Ethyl 6-(benzo[d]thiazol-6-ylamino)-4-(isopropylamino)nicotinate (3) (1 g, 2.8 mmol) in ethanol (20 mL) and water (5 mL) was stirred at rt then added LiOH (14 mmol, 5 equiv.). The reaction mixture was stirred at room temperature for 4 h, the then heated at 70° C. for 1 h. The solvent was concentrated under reduced pressure, diluted with EtOAc and added water. The aqueous layer was collected and acidified to pH 3-4 using solid citric acid. Solid material precipitated out. Filtered the solid material and dried under vacuum to furnish the title compound (4). LC/MS: Acquity BEH C18 2.1×50 mm, 1.8 micron; Solvent A=0.1% TFA in water; Solvent B=0.1% TFA in ACN; gradient 0-100% B over 2 min; retention time: 0.65 min; LCMS (ES-API), m/z 329.8 (M+H).

1. temperaturethe then heated at 70° C. for 1 h
2. concentrationThe solvent was concentrated under reduced pressure
3. additiondiluted with EtOAc
4. additionadded water
5. customThe aqueous layer was collected
6. customSolid material precipitated out
7. filtrationFiltered the solid material
8. customdried under vacuum