Ortho Chloro Para Nitro Aniline

Ortho Chloro Para Nitro Aniline — 2-chloro-4-nitroaniline — carries a chlorine atom ortho to the amino group and a nitro group para to it. The nitro substituent is strongly electron-withdrawing by both induction and resonance, which pulls electron density away from the amino nitrogen and makes this a far less basic, less nucleophilic amine than an unsubstituted aniline. That reduced basicity is not a drawback here: it is exactly the property that makes nitro-substituted chloroanilines of this kind valuable, stable diazonium precursors once diazotized under the stronger acid conditions the azo-pigment industry routinely uses.

At room temperature it is a yellow crystalline solid with a sharply defined melting point, only sparingly soluble in water but soluble in common organic solvents such as acetone and ethanol. Its colour and crystal habit are themselves part of the specification buyers check, since visible discolouration can signal oxidative degradation or contamination.

Where it fits in the synthesis chain

This compound is a classic diazo component used in azoic (naphthol AS) dye and pigment manufacture: it is diazotized and then coupled with a naphthol coupler to build the chromophore of a specific azo colourant. The same chloro-nitroaniline scaffold also appears as a building block in pharmaceutical and fine-chemical synthesis, carried forward through its amino or nitro functional groups.

Grades we supply

Chelora Chemicals offers Ortho Chloro Para Nitro Aniline in technical grade (≈97% assay) for standard industrial synthesis, and high-purity grade (99%+) for applications sensitive to isomer carryover or colour body. Both grades are supplied with a batch-wise certificate of analysis so your incoming QC team can verify the parameters you ordered against.

Ortho Chloro Para Nitro Aniline is manufactured from para-chloronitrobenzene. The chlorine in para-chloronitrobenzene is activated toward nucleophilic aromatic substitution by the strongly electron-withdrawing nitro group sitting para to it, so the ring is first nitrated a second time (or, more commonly, the starting material is built from 2,4-dichloronitrobenzene) and the activated chlorine ortho to the first nitro group is displaced by ammonia under pressure, installing the amino group directly without a separate nitro-reduction step.

An alternative, more traditional route starts from 2,4-dinitrochlorobenzene or a related chloronitrobenzene, with selective reduction of one nitro group to the amine using a controlled catalytic or chemical reduction that leaves the second, more hindered nitro group intact.

After the amination or selective-reduction step, the crude product is washed, recrystallized and dried to remove unreacted starting material, over-reduced by-products and process salts before packing. This recrystallization is where technical grade and high-purity grade material part ways.

Why selectivity matters here

With both a chlorine and a nitro group on the ring, controlling which position reacts — and ensuring only one nitro group is reduced, if that route is used — is the central manufacturing challenge. Buyers specifying this intermediate for diazo-component use care about isomer purity more than almost any other parameter, since a positional isomer carried into the diazotization step couples to give an off-shade pigment batch.