1-benzyl-2,3-dihydroindole-5-carbaldehyde → 5-Methylindoline

Participants

Reaction Steps

Into a 200 mλ atmospheric pressure hydrogenation apparatus equipped with a thermometer and a stirrer, 2.0 g (0.0084 mol) of 1-benzyl-5-formylindoline, 0.4 g of 5% 5 Pd/C and 100 mλ of ethanol were charged, and while introducing hydrogen under atmospheric pressure, a reaction was carried out at from 60 to 70° C. for 8 hours, and when the absorption of hydrogen ceased, the reaction was terminated. After termination of the reaction, the lo palladium catalyst (5% Pd/C) was collected by filtration, and ethanol was distilled off under reduced pressure to obtain a slightly red liquid. The obtained liquid was subjected to vacuum distillation to obtain 0.9 g of 5-methylindoline having a boiling point of 93° C./4 mmHg. The yield was 80.4% (based on the 1-benzyl-5-formylindoline).

Provenance & Evidence