Propylenediamine → 2,6-Dimethyldecahydropyrazino[2,3-b]pyrazine

Temperature

5 °C

To an ice-cold solution of 148 grams, 2.0 moles, of 1-methylethylenediamine in 150 ml of water was added dropwise 145 grams of 40% aqueous glyoxal (58 grams, 1.0 mole). After the addition was completed, the solution was stirred at 5° C. for one hour, then at room temperature for 5 hours. The solution was evaporated on an open tray, and the resulting semi-solid was stirred in 500 ml of acetonitrile and filtered to give 76 grams (46% of product, m.p. 228°-235° C. (dec). Recrystallization from ethanol gave white crystals, m.p. 246-249 (dec.), literature m.p. 210° C.

1. additionAfter the addition
2. waitat room temperature for 5 hours
3. customThe solution was evaporated on an open tray
4. stirringthe resulting semi-solid was stirred in 500 ml of acetonitrile
5. filtrationfiltered

ORD record

ord-d0b58d95ffb44926a9d882dbe9d7561d

Source dataset

uspto-grants-1980_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04218559