Reacción #640560

Ecuación de reacción

hydrochloric acid

Indole-3-pyruvic acid

pyruvic acid

hydroxylamine hydrochloride

4-hydroxy-4-(3-indolylmethyl)-2-ketoglutaric acid

→

4-hydroxy-4-(3-indolylmethyl)-2-hydroxyiminoglutaric acid

Rendimiento 40.0%

Disolventes

—

aqueous solution

sodium hydroxide

sodium hydroxide

sodium hydroxide

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.WAITThe reaction was further continued for 4.5 hours
2. 2
   Otroto yield a reaction mixture
3. 3
   workup.ADDITIONwas added
4. 4
   Extracciónwere extracted with ethyl acetate
5. 5
   LavadoAn organic layer was washed with saturated aqueous NaCl solution
6. 6
   Concentraciónconcentrated
7. 7
   Otroto yield residue
8. 8
   OtroThe residue was recrystallized from 60 mL of 28% aqueous ammonia and 350 mL of 2-propanol

Procedimiento

Indole-3-pyruvic acid (73.8 g, 352 mmol) was added to and dissolved in 917 g of an aqueous solution of 1.6 wt % sodium hydroxide. A temperature of the reaction mixture was maintained at 35° C. As the pH value was maintained at 11.1 using an aqueous solution of 30% sodium hydroxide, 310.2 g (1761 mmol) of an aqueous solution of 50% pyruvic acid was dripped over 2 hours. The reaction was further continued for 4.5 hours to yield a reaction mixture containing 4-hydroxy-4-(3-indolylmethyl)-2-ketoglutaric acid. As the pH value was maintained at 7 with the addition of the aqueous solution of 30% sodium hydroxide, 367.2 g (2114 mmol) of an aqueous solution of 40% hydroxylamine hydrochloride was added thereto, and stirred at 5° C. for 17.5 hours. The pH value of the reaction mixture was adjusted to 2 using concentrated hydrochloric acid, and organic matters were extracted with ethyl acetate. An organic layer was washed with saturated aqueous NaCl solution, and concentrated to yield residue. The residue was recrystallized from 60 mL of 28% aqueous ammonia and 350 mL of 2-propanol to yield 43.4 g of diammonium salt of 4-hydroxy-4-(3-indolylmethyl)-2-hydroxyiminoglutaric acid (142 mmol, yield 40% versus indole-3-pyruvic acid) as crystal.

Fuente