Solution Methylpyridine/water

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. 

Picolinic acid (pyridine-2-carboxylic acid). Equip a 3-litre three-necked flask with a thermometer, sealed stirrer unit and a reflux condenser (Liebig pattern with a wide inner tube). Place a solution of lOOg (106ml, 1.08mol) of 2-methylpyridine in 1 litre of water in the flask and heat to 70 °C on a water bath. Add 450 g (2.84 mol) of potassium permanganate in 10 equal portions through the condenser over a period of 3-4 hours maintain the temperature at 70 °C for the first five additions and at 85-90 °C for the last five. Make each... 

Into a 500-ml three-necked flask fitted with a dropping funnel, a sealed stirrer unit and reflux condenser protected by a drying tube, place a fine suspension of 40 g (lmol) of good quality sodamide (Section 4.2.67, p. 462) in about 150 ml of anhydrous xylene. Introduce 37.5 g (40 ml, 0.4 mol) of 2-methylpyridine through the dropping funnel and rinse the latter with a few ml of dry xylene. Set the stirrer in motion and add 44.5 g (50.5 ml, 0.48 mol) of butyl chloride (Expt 5.50) over a period of 1 hour reflux the mixture with stirring for 2-3 hours. When cold, destroy the excess of sodamide by the cautious addition of 100 ml of water. Transfer the contents of the flask to a separatory funnel and discard the lower aqueous layer. Extract the xylene solution with four 50 ml portions of 1 1 hydrochloric acid. Steam distil the acid extracts to remove traces of xylene, cool the aqueous solution and render strongly alka-... 

Ferrous nitrate hexahydrate (60 mg) followed by sodium (4.5 g, 0.196 g-atom) were added to liquid ammonia. To this mixture was added a solution of 3-methylpyridine (10.0 g, 0.093 mole) in N,N-dimethylaniline (21 ml) over a period of 5 min. The ammonia was allowed to evaporate and the residue heated under nitrogen by means of an oil bath maintained at 180°C for 18 h. The cooled residue was treated with ice (50 g) followed by 2 N sodium hydroxide (50 ml). The mixture was triturated for 2 h and then filtered. The collected solid was washed with boiling toluene (2 times 100 ml). The toluene layer was separated from the combined filtrate and washings, concentrated to about 50 ml and extracted with 5% aqueous acetic acid (5 times 20 ml). The combined extracts were filtered and reduced to dryness. The residue was recrystallized from methylcyclohexane to give 2-amino-3-methylpyridine acetate (4.9 g, 29%), melting point 85°-95°C. The acetate (2.5 g, 1.37 mmoles) was briefly suspended in 1 N sodium hydroxide (50 ml). The mixture was extracted with methylene chloride. The extract was washed with water, dried, and concentrated to give 2-amino-3-methylpyridine as an oil. 

Trifluoromethanesulfonic (triflic) anhydride (0.32 mL, 1.90 mmol) and 2,6-di-f-butyM-methylpyridine (0.396 g, 1.93 mmol) were dissolved in 20 mL of anhydrous CH Clj at 25°C, and to this solution was added 0.475 g (1.36 mmol) of l,2,3,4-tetra-C>-acetyl-3-D-giuco-pyranose (3) [40] in 10 mL of CH Cl. After stirring at 25°C for 1 h, the reaction mixture was poured into 200 mL of ice water containing 2 g of NaHCOj and shaken vigorously. The layers were separated, and the aqueous layer was extracted with 20 mL of CHjClj. The combined organic extracts were dried over NajSO, and the solvent was removed by distillation under reduced pressure. Chromatography produced 4 in 84% yield, mp 85 °C dec. 

Methylpyridine from its oxide 164 Raney nickel (ca. 1 g) is added to a solution of the amine oxide (20 g) in glacial acetic acid (60 ml) and acetic anhydride (10 ml) and the mixture is shaken vigorously under hydrogen at room temperature. When hydrogen absorption ceases most of the nickel can be simply filtered off the filtrate is treated with concentrated hydrochloric acid (about 20 ml) and concentrated to a syrup at 80° under water-pump vacuum. Addition of dilute sodium hydroxide to the residue precipitates nickel hydroxide. After a short time the free base is distilled in steam, separated from the distillate by addition of sodium hydroxide, and dried for several days over solid sodium hydroxide. The residue of base in the aqueous phase is isolated by extraction with ether. Distillation of the united fractions of base affords pure 4-methylpyridine, b.p. 144-145°/760 mm (39.2 g, 84%). 

For aqueous solutions of organic compounds the influence of added salts on the mutual miscibility has also been studied under pressure in some cases. Figure 15 shows results obtained by Engels for the 3-methylpyridine + HjO system with addition of potassium iodide and sodium sulphate, the mass ratio of water to 3-methylpyridine being kept constant at a value of 70/30. The high-pressure immiscibility of the salt-free system (see Figure 9c) is displaced to... 

Figure 5. Deviations of the susceptibility from asymptotic Ising behavior eis a function of AT (a) for a 3-methylpyridine -f water -f sodium bromide (3MP-fH2 0- -NaBr) solution with 16 meiss % NaBr [28] cind (b) for a solution of polystyrene with moleculcir weight 51.5 kg/mol in deuterocyclohexane (PS2) [24]. The symbols indicate experimental data, the solid curve the two-term crossover Landau model, and the dotted curve asymptotic mean-field behavior [53].

Figure 1.18 p-T projection of limited immiscibility regions ( closed-loop or b type) with the hypercritical solution points in the systems methylketone (C4H8O) - H2O (1), 2-butanol (C4H10O) - H2O (2), 2-butoxyethanol (C6H14O2) - H2O (3) and 2-methylpyridine (C6H7N) - H2O (4) (Schneider, G.M. (1973) In Water - A Comprehensive Treatise , edt. F. Franks, Plenum Press, v.2, ch.6, pp. 381 04.). 

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