What Is Isobutyl Quinoline-2?
Isobutyl Quinoline-2 is an aroma chemical prized by perfumers for its bold leather smell. It was first offered by the fragrance house Givaudan, yet over time other suppliers have released versions that match the same odour profile and quality.
The material is made in a laboratory through a multi-step reaction that joins an isobutyl group to a quinoline core. The result is a pale yellow liquid at normal room temperature that flows easily and blends well with most perfume solvents.
In day-to-day fragrance work the ingredient is considered a core building block for leather or woody accords. You will find it in many masculine eau de toilettes, in some vintage chypres and in modern niche creations that need a strong animalic twist.
Supply is steady thanks to several producers so cost sits in the moderate range. It is not the cheapest item on the shelf yet it is affordable enough for regular use in fine fragrance and functional products like soaps or detergents.
When stored in a cool dark place the material stays in good shape for three to four years before the odour starts to thin out. Sealing the drum tightly and keeping it away from strong light or heat helps it last the full term.
Isobutyl Quinoline-2’s Scent Description
This molecule falls squarely into the leather family. On a smelling strip the first impression is a dry worn-in leather similar to an old motorcycle jacket. Within seconds a woody facet flows in that hints at oak bark and cedar shavings. A slight earthy cast adds depth without turning dirty.
Underneath the leather and wood you may notice a faint bitter green tone that keeps the whole effect lively and stops it from feeling flat. The overall aroma is loud and clear rather than subtle so even a tiny dose can dominate a blend.
In the classic top, middle and base note model Isobutyl Quinoline-2 sits firmly in the base. It rises slowly, holds its strength for hours and can still be detected on a blotter five days later. Because it anchors a scent for so long perfumers often use it as the backbone for accords that need staying power.
Projection is strong in the first hour yet it never turns sharp if handled with care. Longevity on skin is impressive, often outliving many other base notes. This tenacity is why it remains a go-to choice whenever a lasting leather signature is required.
How & Where To Use Isobutyl Quinoline-2
Perfumers turn to Isobutyl Quinoline-2 when a composition needs an unmistakable leather accent that lasts. It slips naturally into chypre, fougère and woody fragrances where it can stand in for the smell of saddlery, aged tobacco or even weathered oak.
The material serves best as part of a leather accord alongside birch tar, styrax or castoreum replicas. It can also deepen cedar, vetiver or cypriol notes, giving them a darker almost smoky edge. You might pick it over other leather chemicals such as Suederal or Isobutyl Quinoline-1 when extra power and dryness are required.
Typical use ranges from a trace at 0.01 % for a faint whisper up to about 1 % in bold masculine blends. Givaudan recommends staying below 2 % because the ingredient is extremely tenacious; beyond that level it can dominate the formula, turning harsh and tarry.
Concentration has a big impact on its character. At very low levels it adds subtle suede-like warmth. Medium doses reveal the full saddle leather impression. High doses push the scent toward smoky rubber and can overshadow delicate florals or fruits.
The note excels in fine fragrance, solid perfume, soap bars and incense sticks where heat or alkaline conditions would quickly strip lighter ingredients. It performs less convincingly in fresh aquatic or gourmand styles where its dryness can feel out of place.
Weighing neat Isobutyl Quinoline-2 is tricky because of its strength. Most perfumers pre-dilute it to 10 % in ethanol or dipropylene glycol, making small-scale dosing easier and safer. The liquid dissolves readily in alcohol, oils and most surfactant bases so no special solubiliser is usually needed.
Reserve it for the lower heart or base of the formula. Build brighter notes on top then adjust final dosage once the full drydown has been evaluated on skin and blotter. Thoughtful layering prevents the leather effect from feeling flat or monotonous.
Safely Using Isobutyl Quinoline-2
Dilution is key. Always prepare a working solution before evaluating the smell. Avoid direct sniffing from the bottle because the undiluted vapour is potent and can numb your sense of smell.
Set up in a well-ventilated space or under a fume hood to prevent inhaling concentrated fumes. Protective gloves and safety glasses protect skin and eyes from accidental splashes.
Like many aroma chemicals this material may cause irritation or allergic reactions on sensitive skin. If you are pregnant or breastfeeding consult a healthcare professional before handling any fragrance raw material.
Short exposure to a low concentration is generally regarded as safe yet prolonged or repeated contact with high strength solutions can be harmful. Wash hands after handling and keep containers tightly closed when not in use.
Store the bottle in a cool dark place to slow oxidation and colour change. Use amber glass or aluminium containers with secure lids, and keep them away from heat sources or acids that could degrade the molecule.
Spills should be absorbed with inert material then disposed of according to local hazardous waste rules. Do not pour leftovers down the drain because the strong odour can linger in plumbing.
For the most accurate and up-to-date guidance review the Safety Data Sheet supplied by your vendor. Revisit it regularly as classifications and exposure limits may change. Always check current IFRA standards to confirm that your intended use level stays within recommended limits.
How To Store & Dispose of Isobutyl Quinoline-2
Keep the neat material in tightly sealed amber glass or aluminium bottles placed in a cool dark cupboard. If you have spare fridge space, low-temperature storage slows oxidation even further, but it is not essential provided the room stays below 20 °C and well away from radiators or sunny windows.
Air contact speeds up colour shift and can dull the leather note, so aim to keep containers as full as possible. When you decant, choose bottles that leave minimal headspace then close them with polycone caps. These caps form a better vapour seal than standard droppers, which often leak odour and allow oxygen to creep in.
For working solutions at 10 % or less use the same precautions. Store dilutions in small aliquots rather than one large bottle. If the solution will be opened frequently, nitrogen flushing or a quick burst of canned inert gas before recapping can add extra protection.
Label every container clearly with “Isobutyl Quinoline-2,” its CAS number 93-19-6, concentration, and the date prepared. Add basic hazard phrases like “irritant” or any pictograms required by your region so anyone handling it understands the risk at a glance.
When a bottle reaches the end of its life never pour leftovers down the sink. The compound is persistent and the smell can linger in drains. Small amounts should be absorbed onto vermiculite or paper and sealed in a disposable bag for hazardous waste collection. Larger volumes are best sent for professional chemical incineration where high heat will break the molecule into harmless components.
If a spill occurs ventilate the area, blot with absorbent material then wash the surface with warm soapy water. Dispose of the absorbent as hazardous waste. Although not classed as highly toxic, the material is slow to biodegrade so responsible disposal protects waterways and reduces odour complaints.
Summary
Isobutyl Quinoline-2 is a powerful Givaudan leather note that reads dry woody and slightly smoky on skin. Used in trace to one percent, it anchors chypres, fougères and masculine woods while boosting longevity for days.
The ingredient enjoys steady popularity thanks to its performance, reasonable cost per dose and distinctive signature. It stays stable for years if kept cool and airtight, yet its strength means careful dosing is vital to avoid overpowering lighter accords.
Commercial houses can source it directly from Givaudan or competing aroma suppliers under the same CAS number. Hobbyists will find smaller quantities at specialist perfumery outlets that rebottle from bulk drums. Whether bought in litres or millilitres, the same storage and safety habits ensure you get the most out of this classic leather powerhouse.