反应详情

2-Phenylimidazo[1,2-a]pyrimidin-7-amine (example 1, step 1, 648 mg, 3.08 mmol) and triethylamine (519 mg, 715 μA, 5.13 mmol) were combined with dichloromethane (15 ml) to give a light brown solution. Ethyl 5-(chlorocarbonyl)-1-ethyl-1H-pyrazole-4-carboxylate (1.6 g, 2.57 mmol) was diluted in dichloromethan and was added dropwise at 0° C. The reaction was stirred overnight. The reaction mixture was poured into 20 mL water and extracted with dichloromethan (2×50 mL). The organic layers were dried over Na2SO4 and concentrated in vacuo. The crude material was purified by flash chromatography (silica gel, 50 g, 50% to 100% EtOAc in heptane). The obtained product contained the imide (2 acid chlorides added to amine) as an impurity, but was used in the next step (where the title compound and the impurity give the same product). The title compound was obtained as a light brown solid (510 mg, 49.1%).

1. customto give a light brown solution
2. additionwas added dropwise at 0° C
3. extractionextracted with dichloromethan (2×50 mL)
4. dry with materialThe organic layers were dried over Na2SO4
5. concentrationconcentrated in vacuo
6. customThe crude material was purified by flash chromatography (silica gel, 50 g, 50% to 100% EtOAc in heptane)
7. customthe impurity give the same product)