Reacción #52818

Ecuación de reacción

5-formyl-4-(2-ethoxycarbonylethyl)-3-methyl-1H-pyrrole-2-carboxylic acid ethyl ester

4-methyl-2-oxindole

Potassium hydroxide

→

4-(2-carboxyethyl)-3-methyl-5-(4-methyl-2-oxo-1,2-dihydroindol-3-ylidenemethyl)-1H-pyrrole-2-carboxylic acid

Rendimiento 95.2%

Disolventes

ethanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturathe temperature was increased to 95° C.
2. 2
   workup.WAITheld there for 1 hour
3. 3
   TemperaturaThe reaction mixture was cooled
4. 4
   Concentraciónconcentrated
5. 5
   workup.DISSOLUTIONThe residue was dissolved into water
6. 6
   FiltraciónThe precipitate was filtered
7. 7
   Lavadowashed with water
8. 8
   Otrodried in a vacuum oven overnight

Procedimiento

A mixture of 5-formyl-4-(2-ethoxycarbonylethyl)-3-methyl-1H-pyrrole-2-carboxylic acid ethyl ester (281 mg), 4-methyl-2-oxindole (147 mg) and piperidine (2 drops) in ethanol (2 mL) was stirred at 90° C. for 2 hours. Potassium hydroxide (213 mg) was added, the temperature was increased to 95° C. and held there for 1 hour. The reaction mixture was cooled and concentrated. The residue was dissolved into water and acidified with 2 N hydrochloric acid to pH 2. The precipitate was filtered, washed with water and dried in a vacuum oven overnight to give 337 mg (95%) of 4-(2-carboxyethyl)-3-methyl-5-(4-methyl-2-oxo-1,2-dihydroindol-3-ylidenemethyl)-1H-pyrrole-2-carboxylic acid.

Fuente