2.5- Lutidine

Soluble in water, alcohol, and ether. Miscible with dimethylformamide and tetrahydrofuran.1 

Package Lots. Distill for reuse or place in a separate labeled container for disposal by burning in a furnace equipped with afterburner and scrubber.2 

Small Quantities. Wear eye protection, laboratory coat, and rubber gloves. Dissolve the 2,6 lutidine (1 mL) in 50 mL of 3 M sulfuric acid (prepared by slowly adding 8 mL of concentrated sulfuric acid to 21 mL of water). Weigh 10 g of potassium permanganate and stir small portions of the solid into the 2,6 lutidine solution over a period of about 1 hour. Stir the mixture at room temperature for 48 hours, and then neutralize the solution by adding solid sodium carbonate or a 10% solution of sodium hydroxide. Add solid sodium bisulfite until solution is colorless. Decant the clear liquid into the drain and discard any brown solid with regular refuse.3 

Silvery-white metal slowly oxidizes in moist air. Available as bars, turnings, wire, and powder mp, 651°C bp, HOOT.1 

Powder is easily ignited. Use class D extinguisher or smother with dry sand. Do not use water or carbon dioxide.2 

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It is found in practice that for a number of compounds reacting ma the predominant species an almost horizontal plot is obtained. For compounds presumed to be nitrated via the free bases, such as 2,6-lutidine i-oxide and 3- and 5-methyl-2-pyridone, slopes of approximately unity are obtained. Since this type of plot allows for the incomplete ionisation of nitric acid, it can be used at higher acidities than plots using — ( H + logio Hjo) which break down when the condition is no longer true. 

These arguments were originally applied to the 4-nitration of 2,6-lutidine i-oxide and quinoline i-oxide, and use of the data available... 

Because of these difficulties, special mechanisms were proposed for the 4-nitrations of 2,6-lutidine i-oxide and quinoline i-oxide, and for the nitration of the weakly basic anilines.However, recent remeasurements of the temperature coefficient of Hq, and use of the new values in the above calculations reconciles experimental and calculated activation parameters and so removes difficulties in the way of accepting the mechanisms of nitration as involving the very small equilibrium concentrations of the free bases. Despite this resolution of the difficulty some problems about these reactions do remain, especially when the very short life times of the molecules of unprotonated amines in nitration solutions are considered... 

The carbonyiation of o-diiodobenzene with a primary amine affords the phthalimide 501 [355,356]. Carbonyiation of iodobenzene in the presence of (9-diaminobenzene (502) and DBU or 2,6-lutidine affords 2-phenylbenzimida-zole (503)[357, The carbonyiation of aryl iodides in the presence of pentaflnor-oaniline affords 2-arylbenzoxazoles directly, 2-Arylbenzoxazole is prepared indirectly by the carbonyiation of (9-aminophenol[358j. The optically active aryl or alkenyl oxazolinc 505 is prepared by the carbonyiation of the aryl or enol triflates in the presence of the opticaly active amino alcohol 504, followed by treatment with thionyl chloride[359]. 

Important commercial alkylpyridine compounds are a-picoline (2), Ppicoline (3), y-picoline (4), 2,6-lutidine (5), 3,5-lutidine (6), 5-ethyl-2-methylpyridine (7), and 2,4,6-coUidine (8). In general, the alkylpyridines serve as precursors of many other substituted pyridines used in commerce. These further substituted pyridine compounds derived from alkylpyridines are in turn often used as intermediates in the manufacture of commercially usehil final products. 

Replacing acetaldehyde with acetone and using a co-feed of formaldehyde and ammonia give mainly 2,6-lutidine (5). However, leaving out the formaldehyde results in production of 2,4,6-coUidine (8) as the primary product. 

First, the tar acids were removed from the naphtha fractions of light oils and, in the case of CVR tars, carboHc oil. The oils were then mixed with 25—35% sulfuric acid. After separation of the sulfates, the aqueous solution was diluted with water and the resinous material skimmed off. The diluted sulfate solution was boiled to expel any neutral oils, dried by the addition of soHd caustic soda or a2eotropically with ben2ene, and fractionated to yield pyridine, 2-methylpyridine (a-picoline), and a fraction referred to as 90/140 bases, which consisted mainly of 3- and 4-methylpyridines and 2,6-dimethylpyridine (2,6-lutidine). Higher boiling fractions were termed 90/160 and 90/180 bases because 90% of the product distilled at 160 and 180°C, respectively. 

The o-nitrobenzyl and p-nitrobenzyl ethers can b prepared and cleaved by many of the methods described for benzyl ethers. The p-nitrobenzyl ether is also prepared from an alcohol and p-nitrobenzyl alcohol (trifluoroacetic anhydride, 2,6-lutidine, CH2CI2, 67% yield). In addition, the o-nitrobenzyl ether can be cleaved by irradiation (320 nm, 10 min, quant, yield of carbohydrate " 280 nm, 95% yield of nucleotide ). The p-nitrobenzyl ether has been cleaved by electrolytic reduction (—1.1 V, DMF, R4N X, 60% yield) and by reduction with Na2S204 (pH 8-9, 80-95% yield). These ethers can also be cleaved oxidatively (DDQ or electrolysis) after reduction to the aniline derivative. ... 

TBDMSOSO2CF3, CH2CI2, 2,6-lutidine, 0-25°. This is one of the most powerful methods for introducing the TBDMS group. Other bases such as... 

A secondary alcohol was selectively protected in the presence of a secondary allylic alcohol with TBDMSOTf, 2,6-lutidine at —78°. ... 

MeO)2CH2, 2,6-lutidine, TMSOTf, 0°, 15 min. Similar conditions have been used to introduce MOM ethers on alcohols. 

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