Reacción #5361

Ecuación de reacción

HCl

1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride

4-(chlorophenoxy]pentanoic acid

thiotetronic acid

triethylamine

dimethylformamide

→

4-hydroxy-3-[5-(4-chlorophenoxy)-1-oxopentyl]-2(5H)-thiophenone

Rendimiento 24.0%

Condiciones de reacción

Tratamiento posterior

1. 1
   Extracciónextracted three times with ether
2. 2
   SecadoThe combined organic layers are dried over Na2SO4
3. 3
   Concentraciónconcentrated in vacuo
4. 4
   Otrogiving a yellow solid
5. 5
   OtroThe residue is recrystallized from ethyl acetate/hexane at -78° C.

Procedimiento

To a stirring solution of 224 mg (1.89 mmol) of thiotetronic acid in 10 mL of dimethylformamide is added 290 μL (2.08 mmol) of triethylamine and 77 mg (631 μmol) of 4-dimethylaminopyridine at 0° C. Next, 440 mg (2.29 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 530 mg (2.32 mmol) of 5-[4-(chlorophenoxy]pentanoic acid are added and the reaction mixture is stirred overnight at room temperature. The reaction is acidified with 1.0N HCl and extracted three times with ether. The combined organic layers are dried over Na2SO4 and concentrated in vacuo giving a yellow solid. The residue is recrystallized from ethyl acetate/hexane at -78° C. to give 150 mg (24%) of 4-hydroxy-3-[5-(4-chlorophenoxy)-1-oxopentyl]-2(5H)-thiophenone.

Fuente