反应详情

A mixture of 4-(4-fluorophenyl)-1,2,3-thiadiazole-5-carbaldehyde (180 mg), ethyl diethylphosphonoacetate (450 mg), sodium hydride (60% in oil, 40 mg) and N,N-dimethylformamide (3 ml) was stirred at room temperature for 2 hrs. The reaction mixture was poured into a 1N aqueous hydrochloric acid solution and the mixture was extracted with ethyl acetate. The ethyl acetate layer was concentrated, and a 6N aqueous hydrochloric acid solution (3 ml) and acetic acid (3 ml) were added to the residue. The mixture was stirred for 3 hrs. with heating under reflux. The reaction mixture was concentrated and poured into water. The precipitated solids were collected by filtration, washed with water and dried to give (2E)-3-[4-(4-fluorophenyl)-1,2,3-thiadiazol-5-yl]acrylic acid (130 mg, yield 60%) as a pale-yellow solid.

1. extractionthe mixture was extracted with ethyl acetate
2. concentrationThe ethyl acetate layer was concentrated
3. additiona 6N aqueous hydrochloric acid solution (3 ml) and acetic acid (3 ml) were added to the residue
4. stirringThe mixture was stirred for 3 hrs
5. temperaturewith heating
6. temperatureunder reflux
7. concentrationThe reaction mixture was concentrated
8. additionpoured into water
9. filtrationThe precipitated solids were collected by filtration
10. washwashed with water
11. customdried