Reaction #76485

Reaction equation

product

8-Bromo-1,2,3,4-tetrahydro-2-methyl-5,6-isoquinolinediamine

oxalic acid

→

title compound

Yield 24.1%

6-Bromo-1,4,7,8,9,10-hexahydro-8-methylpyrido[4,3-f]-quinoxaline-2,3-dione

Yield 24.1%

Solvents

HCl

Conditions

Workup

1. 1
   Temperatureat reflux for 18 hours
2. 2
   Otherthe solid which formed
3. 3
   Filtrationwas collected by filtration
4. 4
   Washwashed with cold water
5. 5
   OtherThe solid was recrystallized from hot water
6. 6
   Dryingdried under vacuum (100° C., P2O5)

Procedure

A solution of the product from Example 13 (0.62 g, 2.56 mmol) and oxalic acid (0.23 g, 2.56 mmol) in 25 mL of 3N aqueous HCl solution were heated at reflux for 18 hours. The reaction mixture was cooled to room temperature and the solid which formed was collected by filtration and washed with cold water. The solid was recrystallized from hot water and dried under vacuum (100° C., P2O5) to give the title compound as a tan solid (0.191 g, 20%), mp=315-320° C. (dec.).

Source