Reaction #52795

Reaction equation

6-phenyl-2-oxindole

3-(2-formyl-4,5,6,7-tetrahydro-1H-indol-3-yl)-propionic acid

→

3-[2-(2-oxo-6-phenyl-1,2-dihydro-indol-3-ylidenemethyl)-4,5,6,7-tetrahydro-1H-indol-3yl]-propionic acid

Yield 33.3%

Solvents

ethanol

Conditions

Workup

1. 1
   ConcentrationThe reaction mixture was concentrated
2. 2
   FiltrationThe precipitate was collected by filtration
3. 3
   Washwashed with water and hexane

Procedure

A mixture of 90 mg 6-phenyl-2-oxindole, 95 mg 3-(2-formyl-4,5,6,7-tetrahydro-1H-indol-3-yl)-propionic acid and piperidine ( 3 drops) in ethanol (2 mL) was held in a sealed tube at 90° C. for 4 hrs. The reaction mixture was concentrated and acidified with 6 N hydrochloric acid. The precipitate was collected by filtration and washed with water and hexane to give 59 mg of 3-[2-(2-oxo-6-phenyl-1,2-dihydro-indol-3-ylidenemethyl)-4,5,6,7-tetrahydro-1H-indol-3yl]-propionic acid as a brown solid (31% yield).

Source