Nitrobenzaldehyde

The nitrobenzaldehydes form a group of substances derived from both the benzaldehyde and from nitrobenzene in chemistry. The structure consists of a benzene ring with an added aldehyde ( -CHO) and nitro group (- NO2). Due to their different arrangement (ortho, meta or para), three constitutional isomers with the formula C7H5NO3 result.

Representation

• 2 -nitrotoluene is chlorinated in the heat. That was the end - 2 Nitrobenzylidendichlorid is saponified with 2- nitrobenzaldehyde produced.

• 3-nitrobenzaldehyde is obtained from benzaldehyde by reaction with fuming nitric acid in the presence of concentrated sulfuric acid.

• 4 -nitrobenzaldehyde obtained from 4-nitrotoluene by oxidation with chromium ( VI) oxide in acetic anhydride. The resulting 4- Nitrobenzaldiacetat is hydrolyzed with sulfuric acid in aqueous ethanol.

Properties

The nitrobenzaldehydes are slightly yellow crystalline solids that smell like bitter almonds in part. Of 4 -nitrobenzaldehyde, which has the highest symmetry, has the highest melting point.

In basic medium disproportionate in a Cannizzaro reaction, the nitrobenzaldehydes to nitrobenzoic acids and Nitrobenzylalkoholen.

Use

• 2 -nitrobenzaldehyde is used as a reagent for isopropanol and acetone.

• Acetone 2 -nitrobenzaldehyde reacts to indigo.