sec-Butylamine CAS 13952-84-6

What is sec-Butylamine?

sec-Butylamine is the secondary-carbon primary amine of the butyl series — an amino group on the second carbon of a four-carbon chain, CH₃CH₂CH(NH₂)CH₃. It is a primary amine, despite the name: the "sec" describes the carbon the nitrogen sits on, not the number of groups attached to the nitrogen. That distinction causes genuine confusion in purchasing, so it is worth stating plainly.

The carbon bearing the nitrogen carries four different substituents, which makes sec-butylamine chiral. Commercial material is normally the racemate, an equal mixture of the (R) and (S) forms, but single-enantiomer grades exist and command a substantial premium. In pharmaceutical work the distinction is rarely optional.

It is a clear, colourless, volatile liquid boiling at about 63 °C, with a strong ammoniacal odour. The flash point sits near −18 °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 and strongly basic.

Commercially, sec-butylamine is best known as a post-harvest fungicide in its own right — it has been used directly to control storage rots on citrus and potatoes in several markets, though its registration status varies considerably by territory and has narrowed over time. Beyond that it serves as a chiral building block in pharmaceutical synthesis and as an intermediate for rubber chemicals and specialities.

Why sec-butylamine specifically

• A chiral centre in a small molecule. Few amines this simple carry a stereocentre. That makes sec-butylamine a convenient entry point for chiral resolution and for building single-enantiomer actives.
• Primary amine on a secondary carbon. Two reactive N-H bonds with moderate steric bulk at the alpha carbon — enough to influence selectivity without blocking the reaction.
• Biologically active in its own right. Unusually for a simple amine, it has been used directly as a post-harvest fungicide rather than only as an intermediate.
• Distinct from the other isomers. Shape and chirality both differ from n-, iso- and tert-butylamine. In a registered product the four are separate substances, not grades.

How sec-BA is Manufactured

sec-Butylamine is made by reductive amination of methyl ethyl ketone, or by aminating sec-butanol. Both routes give the racemate; single enantiomers require a resolution or an asymmetric step on top.

• Reductive amination. Methyl ethyl ketone is reacted with ammonia and hydrogen over a nickel or cobalt catalyst at elevated temperature and pressure. The ketone is readily available, which makes this the dominant commercial route.
• Alcohol amination. The alternative passes sec-butanol and excess ammonia over a supported metal or solid acid catalyst with hydrogen present. Either way, di-sec-butylamine forms alongside the mono product.
• Separation. The crude mixture is resolved by fractional distillation with ammonia recovery. Because sec-butylamine boils only a few degrees from isobutylamine, a producer running both needs an efficient column to keep them apart.
• Resolution, where required. The racemate can be resolved with a chiral acid such as tartaric acid, or a single enantiomer accessed through asymmetric synthesis or enzymatic resolution. These grades are made to order and priced accordingly.

Typical Commercial Specification

Figures below are representative of standard racemic commercial grade. Enantiomerically enriched grades and tighter pharmaceutical specifications are available to order — 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 stereocentre carried through into whatever is made from it:

• Chiral salt formation and resolution. Forms diastereomeric salts with chiral acids, which is both how single-enantiomer sec-butylamine is obtained and how it is used to resolve other racemates.
• Amidation and acylation. Reaction with acid chlorides, anhydrides or esters gives N-sec-butyl amides that retain the stereocentre — a recurring motif in crop protection and pharmaceutical actives.
• Substitution on activated heterocycles. Displaces chloride from chlorotriazines and related systems to install the sec-butylamino group.
• Reaction with carbon disulphide and isocyanates. Gives dithiocarbamates, thioureas and substituted ureas used in rubber and crop protection chemistry.

sec-Butylamine 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 sec-BA To

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

Where sec-BA is Used

sec-Butylamine is a specialty product with one unusual property — it is an active in its own right as well as an intermediate. These are the end uses our customers buy it for.

As a post-harvest fungicide

Unusually for a simple aliphatic amine, sec-butylamine has direct biological activity and has been applied as a fumigant or dip to control storage rots on citrus and on potatoes. Its registration status differs widely between territories and has narrowed in several markets over time, so anyone buying for this use needs to confirm the current position at destination before importing — this is one product where the regulatory check genuinely comes before the commercial one.

As a chiral building block

The stereocentre at the second carbon makes sec-butylamine a convenient small chiral amine. Single-enantiomer grades are used to build pharmaceutical intermediates where the finished active's stereochemistry is fixed by the amine, and the racemate is used as a resolving agent to separate other racemic acids through diastereomeric salt formation. Enantiomeric purity has to be specified and verified by a chiral method — a standard assay cannot see it.

In agrochemical synthesis

Used to install the sec-butylamino group on triazine and related ring systems, and as the amine half of substituted ureas and thioureas. Plants running registered actives specify isomer purity tightly, since isobutylamine boils only a few degrees away and the resulting analogue is a different registered compound.

In rubber chemistry

Reaction with carbon disulphide gives sec-butyl dithiocarbamates used as fast accelerators. 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 sec-butylamine from isobutylamine, which boil only a few degrees apart.
• Enantiomeric purity, where specified — chiral GC or HPLC. This is a separate test from assay and has to be requested explicitly; a standard certificate will not report it.
• Amine distribution — the same GC run quantifies di-sec-butylamine and residual ammonia, ketone and alcohol.
• 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 range usually signals isomer carry-over before any instrument confirms it.
• Colour and residue — APHA / Hazen and evaporation residue, both of which matter in pharmaceutical and fine chemical service.

Common Process Problems & Likely Causes

When sec-butylamine 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 arranged where volumes justify them.
• 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. Typically shipped under UN 2733, Amines, flammable, corrosive, n.o.s., Class 3 with subsidiary risk 8, Packing Group II. Confirm the entry and packing group against the current SDS and the shipper's declaration for your destination and mode.
• Container loading. Palletised and secured for FCL; LCL consolidation available by volume.

Hazards & Safe Handling

sec-Butylamine 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

sec-Butylamine is listed on the major national chemical inventories, but it carries an extra layer of regulation that the other butylamines do not: it has been used directly as a pesticide, so in several territories it is subject to crop protection legislation as well as general chemical control. 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.
• Pesticide status. sec-Butylamine has been registered as a post-harvest fungicide in some markets and withdrawn or restricted in others. If your use is agricultural, confirm the current registration position at destination before importing — this is the single most common reason a consignment of this product is held.
• 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. Typically UN 2733, Amines, flammable, corrosive, n.o.s., Class 3 with subsidiary risk 8, Packing Group II. Confirm the entry against the current SDS; declarations prepared for IMDG (sea) or IATA (air) as appropriate.
• 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 sec-BA Worldwide

Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship sec-Butylamine 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 sec-BA from Chelora

We are an independent sourcing and supply partner. For sec-butylamine that means settling two questions before quoting: which optical form you need, and whether the end use is agricultural — because the first decides the manufacturing route and the second decides whether the consignment clears at destination.

• 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 IBC and tank quantities on 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 optical form, isomer purity or analytical method.
• Related intermediates. n-Butylamine, isobutylamine, tert-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 sec-butylamine 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.