Triethylenetetramine → Aminoethylpiperazine

Temperature

150 °C

and 421 g triethylenetetraamine (equivalent weight 39.5; 10.7 equivalents) under a nitrogen atmosphere. The reactants were stirred by an agitator provided in the reactor and heated. As soon as water of condensation appeared in the reactor, the nitrogen gas supply was stopped and the temperature increased to bring the reaction mixture to reflux. The reaction was allowed to continue at a reflux temperature of between 190° C. and 250° C. at atmospheric pressure. The acid value of the reaction mixture was monitored and upon reaching an acid value of 2, the reactor was subjected to a mild vacuum. This was continued until the reaction pressure was reduced to 5 mm Hg. The reaction was continued at these thermodynamic conditions, 190° C. to 250° C. and 5 mm Hg, until the reaction mixture acid value dropped below 1.0.. At that time the reactor was cooled to 150° C., atmospheric pressure was reinstituted, by the addition of nitrogen gas, and Hisol (Ashland Oil Co., highly aromatic solvent) was added to acceptable handling viscosity. The addition of the Hisol permitted cooling of the reaction mixture to ambient temperature. The product of this reaction was a liquid weighing 9,520 g.

1. customprovided in the reactor
2. temperatureheated
3. temperaturethe temperature increased
4. temperatureto reflux
5. customto continue at a reflux temperature of between 190° C. and 250° C. at atmospheric pressure
6. customThis was continued until the reaction pressure
7. customwas continued at these thermodynamic conditions, 190° C. to 250° C. and 5 mm Hg, until the reaction mixture acid value
8. additiondropped below 1.0
9. addition, highly aromatic solvent) was added to acceptable handling viscosity
10. temperaturepermitted cooling of the reaction mixture to ambient temperature

ORD record

ord-6d3edab7d6df4efbab20434f2a56672a

Source dataset

uspto-grants-1991_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05021482