Reaktion #58985

Reaktionsgleichung

hydrochloric acid

4-(4-fluorophenyl)-1,2,3-thiadiazole-5-carbaldehyde

ethyl diethylphosphonoacetate

sodium hydride

→

(2E)-3-[4-(4-fluorophenyl)-1,2,3-thiadiazol-5-yl]acrylic acid

Ausbeute 60.1%

Lösungsmittel

N,N-dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionthe mixture was extracted with ethyl acetate
2. 2
   EinengenThe ethyl acetate layer was concentrated
3. 3
   workup.ADDITIONa 6N aqueous hydrochloric acid solution (3 ml) and acetic acid (3 ml) were added to the residue
4. 4
   workup.STIRRINGThe mixture was stirred for 3 hrs
5. 5
   Temperaturwith heating
6. 6
   Temperaturunder reflux
7. 7
   EinengenThe reaction mixture was concentrated
8. 8
   workup.ADDITIONpoured into water
9. 9
   FiltrationThe precipitated solids were collected by filtration
10. 10
    Waschenwashed with water
11. 11
    Sonstigedried

Vorschrift

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.

Quelle