Isobutylamine CAS 78-81-9

What is Isobutylamine?

Isobutylamine is the singly branched primary amine of the butyl series — an amino group on the terminal carbon of an isobutyl skeleton, (CH₃)₂CHCH₂NH₂. The branch sits one carbon away from the nitrogen, which is the key structural point: the nitrogen itself remains relatively open, so isobutylamine reacts much like n-butylamine while delivering a differently shaped molecule downstream.

It is a clear, colourless, mobile liquid boiling at about 68 °C, with a strong ammoniacal and fishy odour. The flash point sits near −20 °C, so it is highly flammable and the vapour space above the liquid is in the flammable range at ordinary temperature.

It is miscible with water in all proportions and strongly basic, with a conjugate acid pK_a near 10.4. Like all the volatile primary amines it picks up carbon dioxide from air to form a carbamate, which crusts around the closure and discolours the liquid, so drums are kept sealed and colour-sensitive grades are nitrogen-blanketed.

Commercially, isobutylamine is used where the branched alkyl shape matters. It appears in dinitroaniline and other herbicide chemistry, in pharmaceutical intermediates where the isobutyl group is part of the active's identity, in rubber accelerators and in mineral flotation reagents. Volumes are smaller than the linear isomer, and the applications are correspondingly more specific.

Why isobutylamine specifically

• Branch without hindrance. The methyl branch sits one carbon from the nitrogen, so the amine stays reactive while the finished molecule gains a bulkier, more lipophilic alkyl group.
• Shape changes biology. In crop protection and pharmaceutical actives the isobutyl group is often chosen deliberately over n-butyl for the way it fits a binding site. The two are not substitutes.
• Two reactive N-H bonds. It can form amides, ureas, imines and heterocycles that still carry a free N-H for further substitution.
• Good flotation performance. Branched-chain amine derivatives make effective collectors in mineral flotation, where selectivity depends on the exact shape of the hydrocarbon tail.

How IBA is Manufactured

Isobutylamine is made by aminating isobutanol, or by reductive amination of isobutyraldehyde — the latter being readily available from propylene oxo chemistry. Either route produces the di- and tri- amines alongside the mono product.

• Amination or reductive amination. Isobutanol and excess ammonia are passed over a supported metal or solid acid catalyst at elevated temperature and pressure with hydrogen present. The alternative route reductively aminates isobutyraldehyde, a co-product of propylene hydroformylation, with ammonia and hydrogen over a nickel or cobalt catalyst.
• Ratio control. A high ammonia-to-substrate ratio suppresses further alkylation and pushes the distribution toward the mono amine. Surplus di-isobutylamine is recycled or taken off as a co-product.
• Separation. The crude mixture is resolved by fractional distillation with ammonia recovery. Because isobutylamine and n-butylamine boil only about 10 °C apart, a producer running both needs a genuinely efficient column to keep them separate.
• Drying and finishing. The mono cut is dried to specification and filled into drums, IBCs or tanks, with nitrogen blanketing where colour and water specification matter.

Typical Commercial Specification

Figures below are representative of standard commercial grade. Tighter agrochemical and pharmaceutical grades with lower isomer, water and metals limits are available — send us the specification you work to and we will quote against it.

Physical & Chemical Properties

Reactivity in practice

The chemistry runs through the nitrogen lone pair and the two replaceable N-H hydrogens, with the branch far enough away to leave the nitrogen reactive:

• Aromatic substitution. Displaces activated halide or nitro-activated leaving groups to install the isobutylamino group on aromatic and heteroaromatic rings — the basis of its agrochemical chemistry.
• Amidation and acylation. Reaction with acid chlorides, anhydrides or esters gives N-isobutyl amides, a recurring motif in pharmaceutical and crop-protection actives.
• Reaction with carbon disulphide. Gives dithiocarbamates used as rubber accelerators and as flotation collectors in mineral processing.
• Reductive amination and alkylation. Condenses with aldehydes and ketones to imines that reduce to secondary amines, and alkylates onward to tertiary amines and quaternary salts.

Isobutylamine vs the Other Butylamine Isomers

All four butylamine isomers share the formula C₄H₁₁N and a molecular weight of 73.14, and differ only in where the amino group sits on the four-carbon skeleton. That single difference moves the boiling point by more than 30 °C across the set, changes how crowded the nitrogen is, and decides which registered products the molecule can go into. They are separate substances with separate CAS numbers, not grades of one another.

Stated plainly: the more branched the carbon bearing the nitrogen, the lower the boiling point and the more crowded the amine. n-Butylamine is linear and reacts freely; isobutylamine is branched one carbon away and behaves similarly with slightly more bulk; sec-butylamine carries a chiral centre, which matters in pharmaceutical work; tert-butylamine is fully branched at the nitrogen-bearing carbon, which slows some reactions and makes the resulting derivatives notably more hydrolytically stable. Chelora supplies all four.

Industries We Supply IBA To

The same molecule leaves our warehouse for very different factories. What changes between them is not the CAS number but the grade, the packing and the documentation each sector expects.

Where IBA is Used

Isobutylamine is a specialty intermediate chosen for the shape of its alkyl group. These are the end uses our customers buy it for, roughly in order of volume.

In herbicide manufacture

The isobutylamino group appears in dinitroaniline and related herbicide structures, where the branched alkyl tail contributes directly to how the molecule partitions into the target tissue. Plants running registered actives specify the n-butylamine figure tightly: the two isomers boil only about 10 °C apart, so carry-over is a genuine risk, and the resulting linear analogue is a different registered compound rather than a removable impurity.

In pharmaceutical synthesis

Used to form N-isobutyl amides, to open epoxides into isobutylamino alcohols, and to build N-isobutylated heterocycles. The isobutyl group is frequently chosen over n-butyl for the way it occupies a hydrophobic pocket, so substitution is not an option. API producers run the tightest specifications in the market, with residual alcohol, isomer carry-over and metals all needing to clear ICH limits.

In mineral flotation

Branched-chain amines and their dithiocarbamate derivatives make effective flotation collectors, and selectivity between target and gangue minerals depends in part on the exact shape of the hydrocarbon tail. Reagent blenders generally care more about batch-to-batch consistency than about absolute purity, since a plant's flotation circuit is tuned to a particular reagent behaviour.

In rubber chemistry

Reaction with carbon disulphide gives isobutyl dithiocarbamates, used as fast accelerators where short cure cycles matter. Consistency of the amine distribution matters more here than extreme purity, since a shifting feed changes the accelerator blend rather than failing a specification outright.

Quality Control & Testing

Every lot is released against a batch-specific Certificate of Analysis. The methods behind the numbers are standard across the industry, and we are happy to share them or to work to your own in-house test protocol.

• Assay and isomer separation — gas chromatography on a column capable of resolving isobutylamine from n-butylamine, which a general-purpose method may not do reliably.
• Amine distribution — the same GC run quantifies di- and tri-isobutylamine and residual ammonia and isobutanol.
• Water content — Karl Fischer titration, the specification that most often decides whether a lot performs in acid-chloride chemistry.
• Distillation range — a fast, revealing check. A broadened or depressed range usually signals isomer carry-over before any instrument confirms it.
• Colour — APHA / Hazen against a standard. Colour drift signals air ingress, carbon dioxide pickup or metal contamination.
• Metals and residue — iron and evaporation residue, both of which matter in pharmaceutical and fine chemical service.

Common Process Problems & Likely Causes

When isobutylamine misbehaves in a plant, the cause is usually one of a short list of things. This table is the shortcut our technical desk works through before anyone opens a complaint file.

Packaging, Storage & Shipping

• Standard packing. 150 kg net in lined steel or HDPE drums, with 1000 L IBCs for larger users.
• Bulk packing. Road tankers and ISO tank containers for continuous processes.
• Inert blanketing. Nitrogen-blanketed at fill where the grade and end use call for it, to protect colour and water specification in storage.
• Storage. Cool, shaded, well-ventilated and bunded area away from heat, ignition sources, oxidisers and acids, with containers kept tightly closed.
• Materials of construction. Stainless steel, carbon steel or suitable lined vessels. Avoid copper, brass, bronze, aluminium and mercury, all of which are attacked by amines.
• Shelf life. Typically 12 months in unopened original packing under those conditions. Beyond that, re-test rather than assume.
• Transport classification. UN 1214, Isobutylamine, Class 3 flammable liquid, Packing Group II — shipped with full dangerous-goods documentation. Confirm the subsidiary risk entry against the current SDS for your destination.
• Container loading. Palletised and secured for FCL; LCL consolidation and tank arrangements available by volume.

Hazards & Safe Handling

Isobutylamine is highly flammable and corrosive, and must be handled by trained personnel under a proper risk assessment. The classifications below are indicative — the current SDS supplied with your consignment is the governing document.

• Exposure control. Handle in a closed system or under local exhaust ventilation. The flash point is below ambient, so the vapour space above the liquid sits in the flammable range in normal storage.
• PPE. Chemical-resistant gloves, chemical goggles and face shield, chemical-resistant clothing, and respiratory protection suited to the task.
• Ignition control. Vapours are heavier than air, travel along the ground to a distant ignition source and flash back. Bonded, earthed and explosion-proof equipment, and no ignition sources in the zone.
• Incompatibilities. Strong oxidising agents, strong acids, acid chlorides, nitrites, mercury, and copper, brass, bronze and aluminium equipment.
• Spill response. Eliminate ignition sources and ventilate. Contain, absorb with inert non-combustible material and collect in a labelled closed container. Do not wash to drain.
• Environment. Do not allow to enter drains, surface water or groundwater. Dispose through a licensed chemical waste contractor.
• Fire. Highly flammable. Use alcohol-resistant foam, dry chemical or carbon dioxide; cool exposed containers with water spray. Decomposition releases nitrogen oxides — use self-contained breathing apparatus.
• First aid. Move to fresh air, remove contaminated clothing immediately, wash skin with plenty of water, flush eyes for at least 15 minutes, and seek medical attention with the SDS to hand.

Regulatory & Compliance Notes

Isobutylamine is an established industrial chemical and is listed on the major national chemical inventories. Because obligations differ by territory, volume and use, the notes below are orientation rather than legal advice — confirm your own position with your regulatory adviser before importing.

• Inventory status. Listed on the principal chemical inventories in the major importing regions. Ask us for the inventory confirmation relevant to your destination country.
• Isomer identity. The four butylamine isomers are separate substances with separate CAS numbers and separate registrations. Make sure your import documentation, inventory listing and end-use approval all name the isomer you are actually buying.
• Import registration. Several territories require the importer to hold a registration or notification before a consignment lands. Start that process early — it is the most common cause of delay at destination.
• Hazard communication. Supplied with an SDS compliant with the format applicable to your region, and labelled in line with the GHS classification for the product.
• Dangerous goods. UN 1214, Isobutylamine, Class 3 flammable liquid, Packing Group II. Declarations prepared for IMDG (sea) or IATA (air) as appropriate to the mode; confirm the subsidiary risk entry against the current SDS.
• Workplace exposure. Occupational exposure limits apply in most jurisdictions. Set your controls against the limit in force where the material will be handled.

We Supply IBA Worldwide

Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Isobutylamine from India to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation, dangerous-goods paperwork and freight so the material arrives ready to use.

• Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
• Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other Indian ports arranged where it suits the routing.
• Documentation. Commercial invoice, packing list, certificate of origin, COA, SDS and dangerous-goods declaration issued as a complete set.
• Flexible volumes. A single drum for laboratory qualification, through LCL consolidations, up to repeat full loads on a supply contract.
• Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.

Buying IBA from Chelora

We are an independent sourcing and supply partner. For isobutylamine that means matching the grade to the application and taking isomer purity seriously — the linear isomer boils only about 10 °C away, and in a registered product it is a different molecule rather than an impurity.

• Documentation on every lot. Batch-specific COA, current SDS and TDS issued with the consignment, not weeks afterward.
• Samples before commitment. Trial quantities for process qualification ahead of a commercial order.
• Quantities. From a single 150 kg drum through to tank loads and ongoing contract supply.
• Export experience. Dangerous-goods documentation, packing and labelling handled for sea and road freight to any destination.
• Technical support. Direct access to people who know the chemistry, for questions on isomer purity, analytical method or materials compatibility.
• Related intermediates. n-Butylamine, sec- and tert-butylamine, di-n-butylamine and the wider aliphatic amine range from one supplier.

How ordering works

• Send the enquiry. Product, grade or specification, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
• We quote. Price, lead time, packing and a sample COA, normally within one working day.
• Sample and qualify. For first orders or critical applications, we send a trial quantity so your lab can sign off before you commit.
• Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
• Production and QC. Material allocated and released against a batch-specific COA, with a pre-shipment sample where the application calls for it.
• Ship and document. Packed, labelled and loaded with the full export and dangerous-goods document set, and tracked through to arrival.

Related Amines & Intermediates

Buyers of isobutylamine usually source several of these alongside it. Consolidating them on one order cuts freight cost and gives you a single point of contact for documentation.