反应详情

A 250-mL round bottomed flask was charged with 5-chlorothiophene-2-carboxamidine HCl salt (6.81 g, 34.6 mmol, 1 eq.), ethyl 2-ethyl-3-oxo-butanoate (12 g, 72 mmol, 2 eq.), and ethanol (100 ml). To the mixture was added sodium methoxide (25 w % in methanol, 23 g, 107 mmol, 3 eq.). The resulting mixture was stirred under reflux for 7 hr. After cooling to room temperature, the mixture was evaporated under reduced pressure to dryness and the residue was treated with 2N HCl (60 ml). Solid was collected by filtration and washed with water followed by ether. The product thus obtained was forwarded to the next step without any further purification (4.53 g, 51% yield).

1. temperatureunder reflux for 7 hr
2. customthe mixture was evaporated under reduced pressure to dryness
3. additionthe residue was treated with 2N HCl (60 ml)
4. filtrationSolid was collected by filtration
5. washwashed with water
6. customThe product thus obtained
7. customwas forwarded to the next step without any further purification (4.53 g, 51% yield)