o-Aminophenethyl alcohol → Indoline

Participants

Reaction Conditions

Reaction Steps

In a stainless steel reactor equipped with distillation column, 0.8 g of a commercially available amorphous aluminium silicate (KETJEN® LA-100-3P) consisting of 13.3% by weight of Al2O3 and 86.3% by weight of SiO2, and having a BET inner surface area of 403 m2 /g and a pore volume of 0.52 cm3 /g, are suspended in 80 g (72 ml) of 2-(2'-aminophenyl)ethanol using a magnetic stirrer. The suspension is heated to 240° C. under normal pressure and the resultant indoline/water mixture is distilled off through the packed column at a rate of 25 g of indoline per hour. During this distillation, the volume in the reactor is kept constant with a level probe by the continuous addition of fresh 2-(2'-aminophenyl)ethanol. To maintain this distillation rate, the reaction temperature is gradually raised during the entire duration of the experiment of 126 hours from initially 240° C. to 270° C. After 126 hours, the addition of 2-(2'-aminophenyl)ethanol is discontinued and the indoline remaining in the reactor is distilled off through the column, affording 2.95 kg (97-98% of theory) of indoline in 99% purity.

Provenance & Evidence