Ethylenediamine → Pyrazino[2,3-b]pyrazine, decahydro-

Temperature

80 °C

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##

1. customIn a 250-ml round bottom flask was placed
2. additionwas added dropwise during the next 30 minutes
3. customDuring the heating period of crystals formed in the solution
4. temperatureto slowly cool to room temperature
5. temperaturecooled to 0° C
6. filtrationThe product was then collected by vacuum filtration
7. washwashed with cold 50% ethanol

ORD record

ord-1aff7c8dbbb248fa9707b1ce44d84d13

Source dataset

uspto-grants-1984_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04443602