Reaction #3512

Reaction equation

2,4-diamino-5-cyanopyridine

formic acid

hydrogen

→

title compound

2,4-Diaminonicotinaldehyde

Solvents

water

Conditions

Workup

1. 1
   Otherwas consumed
2. 2
   OtherThe solvents were removed under reduced pressure
3. 3
   workup.ADDITIONthe residue treated with 17 mL of concentrate HCl
4. 4
   Filtrationfiltered
5. 5
   Washwashed with isopropyl alcohol
6. 6
   Otherdried
7. 7
   OtherCrystallization from ethanol

Procedure

A suspension of 13.4 g of 2,4-diamino-5-cyanopyridine from Example 14, 2 g of Raney nickel catalyst, 40 mL of 97-100% formic acid, and 80 mL of water were shaken in a Parr apparatus under an atmosphere of nitrogen until the requisite amount of hydrogen was consumed. The solvents were removed under reduced pressure and the residue treated with 17 mL of concentrate HCl. The resulting pink solid was slurried in a small amount of water, filtered, washed with isopropyl alcohol, followed by diethylether, and dried. Crystallization from ethanol afforded 6.5 g of the title compound 2,4-diaminonicotinaldehyde.

Source