Potassium Carbonate → HCID 86746624, compound

Participants

Reaction Steps

A total of 180.0 grams (2.0 mole) of dimethyl carbonate, 17.4 grams (0.1 mole) of 1,4-bis(2-hydroxyethyl)piperazine and 1.0 gram (0.007 mole) of potassium carbonate were combined in a 250 milliliter round bottom flask equipped with a straight distillation head and a magnetic stirrer. The flask contents were heated to reflux under a nitrogen atmosphere. Initial reaction temperatures at reflux were 80° C. at the head and 88° C. on the kettle. A methanol/dimethyl carbonate azeotrope was removed overhead over a period of 7.5 hours. After this time, the flask contents were cooled and the kettle contents were analyzed by capillary gas chromatography (FlD) using a DB-1701 column. The 1,4-bis(2-hydroxyethyl)piperazine was totally converted to a mixture of methyl bis(2-piperazinoethyl)carbonate and bis(methyl 2-piperazinoethyl)carbonate. The kettle contents were heated for an additional period of 2.5 hours after which the reaction was stopped. The kettle contents were concentrated in vacuo at 20 mm Hg and a temperature of 60° C. using a rotary evaporator. A total of 26.6 grams of material which was about 88 percent pure in bis(methyl 2-piperazinoethyl)-carbonate was obtained. The major by-products were 1,4-bis(2-hydroxyethyl)piperazine methyl carbonate (ca. 1.5 percent) and bis[1,4-(2-hydroxyethyl)-piperazine]carbonate (ca. 9.9 percent).

Provenance & Evidence