反应详情

To a refluxing solution of thiourea (2.6 g, 34.3 mmol) in absolute ethanol (30 mL) was added ethyl 2-bromo-3-oxopentanoate (7.3 g, 32.7 mmol) always keeping the mixture at reflux. The solution was stirred at reflux for another 1.5 hours. After cooling to room temperature, the solution was poured in ice/water (150 mL). The mixture was neutralized with concentrated NH4OH. The solid material was recovered by filtration, washed with water (2×50 mL) and hexanes (3×50 mL), and dried in vacuo, affording ethyl 2-amino-4-ethyl-1,3-thiazole-5-carboxylate (6.8 g, 94% yield). The product was used without further purification.

1. temperatureat reflux
2. temperatureat reflux for another 1.5 hours
3. filtrationThe solid material was recovered by filtration
4. washwashed with water (2×50 mL) and hexanes (3×50 mL)
5. customdried in vacuo