5-Nitro-2H-benzimidazol-2-one → 5-amino-2H-1,3-benzodiazol-2-one

Participants

Reaction Conditions

Reaction Steps

0.001 g of ammonium vanadate and 0.5 g of titanium dioxide extrudate containing 1% by weight of metallic palladium and having a particle size of 3 mm (from Johnson Matthey) are added to a suspension consisting of 50 ml of water and 1.8 g of 5-nitrobenzimidazolone. After displacing the air with nitrogen, the latter is replaced by hydrogen at atmospheric pressure and the suspension is stirred at 60° C. for 34 hours. During this time, 102% of the theoretical amount of hydrogen, based on the 5-nitrobenzimidazolone, is adsorbed. The resulting suspension is then sieved through a sieve having a mesh width of 1 mm. The material remaining on the sieve is washed with 50 ml of water and the combined aqueous phases are then filtered through a paper filter and washed with 250 ml of water. Drying at 80° C. under reduced pressure (125 mbar) gives 1.2 g (79%) of 5-aminobenzimidazolone.

Provenance & Evidence