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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 26704Generated: October 25, 2026

Formic Acid → 5-Nitrobenzimidazole

https://huagongshe.com/reaction/26704

Reaction equation

Participants

RoleNameHCIDCharge
ReactantFormic AcidHCID 284—
ReactantAmmonium HydroxideHCID 14923—
Reactant4-Nitro-1,2-phenylenediamineHCID 5111791—
SolventHydrochloric AcidHCID 313—
Product5-NitrobenzimidazoleHCID 719589%

Reaction Conditions

Temperature80 °C

Reaction Steps

15 ml of formic acid were added to a suspension of 15.3 g of 4-nitro-1,2-phenylenediamine in 150 ml of 10% hydrochloric acid and the mixture was stirred on a water bath at 80° C. for 3 hours and was cooled. The mixture was made alkaline with concentrated ammonium hydroxide solution and the mixture was filtered. The yellowish needles were washed with water and dried over P2O5 under reduced pressure to obtain 14.3 g (89% yield) of 5(6)-nitro-benzimidazole melting at 209°-211° C.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS04151280
Source datasetuspto-grants-1979_04
ORD IDord-ad13d81e56da485d8fb7cb2484db1443
Source noteuspto-grants-1979_04