N-Butyllithium must be calibrated through single titration as follows:
1) Titration solution: 1mol/L SEC butanol/dimethylbenzene solution (butanol and dimethylbenzene must be dried with an activated 5A molecular sieve)
2) Indicator: 2,2’-dipyridine
3) Solvent: dimethylbenzene (must be dried with an activated 5A molecular sieve).
4) Operation method: Under the protection of argon, add magneton, 20ml dimethylbenzene and a small amount of indicator into a 100ml 3-lipped bottle with a tipping plug. Then use a precisely marked 2ml injector to swiftly transfer 2ml N-Butyllithium into the bottle (the air in the injector must be replaced with argon, which must then be expelled when collecting the N-Butyllithium; fill and drain the injector in the N-Butyllithium multiple times to prevent any water or air from remaining in the injector). The system should turn a purplish red. Then, wash, dry, and rinse the same injector with titration solution 2-3 times (to prevent any change in the amount added) and titrate the solution until the system turns yellow, and cease titration.
5) Repeat titration once; if the percent error between the two times is within 2%, the result can be regarded as correct.
6) Titration result: titration solution (ml)/2 to obtain N-Butyllithium concentration.
Store in ventilated, cool and dry spaces; must be waterproof and carbon dioxide-proof.
Colorless or slightly yellow transparent liquid at room temperature, also comes in powder form. Boiling point is 80-90℃（0.013Pa）, relative density is 0.68-0.70. Soluble in many organic solvents. Stable in room temperature, lithium hydride removable by heating. Disintegrates in water, soluble in hydrocarbons and ethers, forms complex compounds with ethers, amines, and sulfides, and uses N-hexane as a solvent.
Combusts in air at a concentration abover 20%; combusts upon contact with water and carbon dioxide; flammable when in contact with heat and open flame.
May explode in combination with phenylethylene
Spontaneously combustible when in contact with water
Warnings and precautions
1) N-Butyllithium is extremely combustible when in contact with air; when measuring, the needle of the injector will eject sparks.
2) The entire process must be protected by argon for safety precaution.
3) If N-Butyllithium catches fire, it must be extinguished with sand, which must be placed within arm’s reach at all times.
When preparing and using N-Butyllithium, do not operate alone in case of emergency
clear yellow solution
N-Butyllithium solution is mostly used as a pharmaceutical intermediate to synthesize anionic polymerization initiator. It is also used to produce rubber (such as integral rubber SIBR, which is the most versatile diene rubber to date), fragrance, liquid crystal materials, and other industries. It is a chemical product intermediate, linking agent, alkylating agent, and polymerization catalyst. As a catalyst, N-Butyllithium is widely used as a pharmaceutical intermediate, liquid crystal monomer, and pesticide production catalyst. It is also widely used in organic syntheses, especially in growing carbon chains, and it is a staple laboratory product in reactions such as: 1) Metallization reaction: R-H + n-Butyl-Li → R-Li + Butane, in which the produced lithium alkyl can react with many substances. 2) Direct metallization: the aromatic compound that connects the substitute reacts with N-Butyllithium, and lithium metal can be attached to the aromatic compound. 3) Nucleophilic addition and substitution reaction. 4) Halogen-metal replacement.