2,4-Diaminotoluene → 2,3-Dinitrotoluene

Participants

Reaction Steps

An autoclave having a volume of 1000 ml and equipped with a gassing stirrer, a hydrogen supply pipe, an inlet pipe for the nitro compound and an outlet valve for excess hydrogen was used. The reaction mixture left the reactor through a frit, which retained the catalyst. The temperature in the reactor was regulated by means of an external heating or cooling circuit. A coiled cooling pipe inside the reactor provided additional cooling of the reaction mixture. 480 g of a commercial mixture comprising a mixture of 80% 2,4-diaminotoluene and 20% 2,6-diaminotoluene (TDA) with water in a weight ratio of TDA to water of 63:37 as well as 5.0 g-6.5 g of catalyst were placed in the reactor. The contents of the reactor were then placed under pressure by means of hydrogen and heated. At a temperature of 180° C. and a pressure of 26 bar, 125 g/h of a commercial mixture of 80% 2,4-dinitrotoluene and 20% 2,6-dinitrotoluene were passed into the reactor hourly and hydrogenation was carried out until the catalyst was exhausted. The resulting hydrogenation product was removed from the reactor continuously and worked up to form the pure diaminotoluene isomeric mixture.

Provenance & Evidence