1,2,3,4,4a,5,6,7,8,8a-decahydropyrazino[2,3-b]pyrazine

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 250-ml round bottom flask was placed 24.0 g of ethylene diamine (0.40 mole). This was cooled to 0° C. by a salt/ice bath and 14.5 g of 40% aqueous glyoxal solution (0.10 mole) was added dropwise during the next 30 minutes. This solution was then heated at 80° C. for 5 hours. During the heating period of crystals formed in the solution. The solution was allowed to slowly cool to room temperature, then cooled to 0° C. The product was then collected by vacuum filtration and washed with cold 50% ethanol. The yield of product m.p. 162°-170° C. (decomposition) is 12.0 g (0.085 mole, 85%). ##STR2## In a 250-ml round bottom flask was placed was added dropwise during the next 30 minutes During the heating period of crystals formed in the solution to slowly cool to room temperature cooled to 0° C The product was then collected by vacuum filtration washed with cold 50% ethanol

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 250-ml round bottom flask was placed 24.0 g of ethylene diamine (0.40 mole). This was cooled to 0° C. by a salt/ice bath and 14.5 g of 40% aqueous glyoxal solution (0.10 mole) was added dropwise during the next 30 minutes. This solution was then heated at 80° C. for 5 hours. During the heating period of crystals formed in the solution. The solution was allowed to slowly cool to room temperature, then cooled to 0° C. The product was then collected by vacuum filtration and washed with cold 50% ethanol. The yield of product m.p. 162°-170° C. (decomposition) is 12.0 g (0.085 mole, 85%). ##STR2## In a 250-ml round bottom flask was placed was added dropwise during the next 30 minutes During the heating period of crystals formed in the solution to slowly cool to room temperature cooled to 0° C The product was then collected by vacuum filtration washed with cold 50% ethanol

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 250-ml round bottom flask was placed 24.0 g of ethylene diamine (0.40 mole). This was cooled to 0° C. by a salt/ice bath and 14.5 g of 40% aqueous glyoxal solution (0.10 mole) was added dropwise during the next 30 minutes. This solution was then heated at 80° C. for 5 hours. During the heating period of crystals formed in the solution. The solution was allowed to slowly cool to room temperature, then cooled to 0° C. The product was then collected by vacuum filtration and washed with cold 50% ethanol. The yield of product m.p. 162°-170° C. (decomposition) is 12.0 g (0.085 mole, 85%). ##STR2## In a 250-ml round bottom flask was placed was added dropwise during the next 30 minutes During the heating period of crystals formed in the solution to slowly cool to room temperature cooled to 0° C The product was then collected by vacuum filtration washed with cold 50% ethanol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To an ice-cold solution of 206 grams of 70% aqueous ethylenediamine (144 grams, 2.4 moles) was added dropwise 115 grams of a 30% aqueous solution of glyoxal (34.8 grams, 0.6 mole). When the addition was completed, the solution was stirred at room temperature for 30 minutes, then concentrated by removing approximately 75 ml of water at 150 mm Hg. The mixture was cooled in an ice bath and the precipitated solid was filtered, stirred in 100 ml of 50% ethanol-isopropanol, and again filtered. The yield of product was 50.6 grams (59%), m.p. 222°-225° C. (dec; literature m.p. 230°-232° C.). When the addition concentrated by removing approximately 75 ml of water at 150 mm Hg The mixture was cooled in an ice bath the precipitated solid was filtered stirred in 100 ml of 50% ethanol-isopropanol again filtered

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 250-ml round bottom flask was placed 24.0 g of ethylene diamine (0.40 mole). This was cooled to 0° C. by a salt/ice bath and 14.5 g of 40% aqueous glyoxal solution (0.10 mole) was added dropwise during the next 30 minutes. This solution was then heated at 80° C. for 5 hours. During the heating period of crystals formed in the solution. The solution was allowed to slowly cool to room temperature, then cooled to 0° C. The product was then collected by vacuum filtration and washed with cold 50% ethanol. The yield of product m.p. 162°-170° C. (decomposition) is 12.0 g (0.085 mole, 85%). ##STR2## In a 250-ml round bottom flask was placed was added dropwise during the next 30 minutes During the heating period of crystals formed in the solution to slowly cool to room temperature cooled to 0° C The product was then collected by vacuum filtration washed with cold 50% ethanol