2-(4'-Methylphenyl)-pyridine (CAS NO.: ) could be produced through the following synthetic routes.

A. 2-(4'-Methylphenyl)-pyridine N-oxide. A 1-L, three-necked round-bottomed flask is equipped with a magnetic stir bar (cylindrical, 4 × 1 cm), two glass stoppers and a reflux condenser with a gas bubbler on the top and connection to the argon line. Pd(OAc)₂ (0.560 g, 2.50 mmol, 5 mol%), PtBu₃.HBF₄ (0.870 g, 3.00 mmol, 6 mol%), potassium carbonate powder (K₂CO₃, 8.97 g, 65.0 mmol, 1.3 equiv), and pyridine N-oxide (19.0 g, 200 mmol, 4 equiv) are weighed in air and placed inside the flask. The whole setup is then evacuated (0.4 mmHg) and refilled with argon four times.

A solution of (8.55 g, 50 mmol, 1 equiv) in (300 mL) is added under a steady flow of argon to the reaction mixture, and the glassware is rinsed with degassed toluene (30 mL). The obtained brown-orange suspension is immersed in the oil bath. Stirring (700 rpm) is commenced and the ing source is turned on (set to 125 °C). The mixture starts to reflux after approximately 45 min.

Heating and stirring under a steady flow or argon is maintained for 16 h (overnight). The now black reaction mixture is allowed to cool to room temperature and transferred to 1-L round-bottomed flask. The reaction flask is rinsed with toluene (50 mL), and the solvent is removed under reduced pressure (40 °C, 40 mmHg) on a rotary evaporator. A saturated aqueous solution of NH₄Cl (150 mL) and DCM (200 mL) are sequentially added to the dark slurry. The mixture is filtered through a Celite® pad. The glassware is washed with water (50 mL) and DCM (2 × 50 mL). The resulting yellow biphasic solution is transferred into a 1-L separatory funnel and the layers are separated. The aqueous layer is washed with DCM (2 × 100 mL).The combined organic layers are dried over MgSO₄ (4 g), filtered and washed with DCM (2 × 50 mL). The solvent is removed under reduced pressure (40 °C, 500 mmHg). The resulting yellow solid is then dissolved in eluent (20 mL), charged on a column (7 × 8.5 cm) of silica gel and eluted with DCM/acetone/MeOH 90:8:2 mixture (3.5 L). After the first 300 mL of eluent, fraction collection (20-mL fractions) is started. The desired product is obtained from fractions 18-120 as beige solid (6.51 g, 35.1 mmol, 70%).

The solid obtained after column chromatography is placed in a 250-mL round-bottomed flask equipped with a magnetic stir bar (egg shaped, 2 × 1 cm) and a reflux condenser. Heptane (40 mL) and toluene (20 mL) are added, and the suspension is heated to 115 °C (700 rpm). Toluene is added in 5 mL portions through the reflux condenser over 20-30 30 min until a clear solution is obtained (the total volume of toluene used is 40 mL). A gas bubbler is placed on top of the condenser and connected to the argon line. The heating source is turned off and the clear (yellow solution) is allowed to cool down to rt overnight (14 h) under argon, while stirring is maintained. The obtained suspension is cooled down to 0 °C with the help of an ice bath and stirred for 1 h. The resulting solid is collected by filtration using a 50-mL Büchner funnel under a stream of nitrogen and washed with ice-cold heptane (3 × 20 mL). The obtained solid is transferred to a 100-mL round-bottomed flask and dried overnight (>12 h) at 0.1 mbar to provide the title compound as a white solid (5.98 g, 32.3 mmol, 65%).

B. 2-(4'-Methylphenyl)-pyridine (CAS NO.: ). A three-necked, 500-mL round-bottomed flask equipped with a condenser, a thermometer, a glass stopper and a magnetic stirrer (egg shaped, 3 × 1.5 cm) is charged with 2-(4'-methylphenyl)-pyridine N-oxide (5.98 g, 32.3 mmol, 1 equiv). (120 mL) is added, followed by saturated aqueous NH₄Cl solution (120 mL). This addition caused a slight increase of the reaction temperature from 22 °C up to 28 °C, and a white solid is formed in the aqueous layer. dust is added in 4 portions (10.6 g, 161 mmol, 5 equiv) within 10 min under stirring (700 rpm) to this biphasic mixture. Again, an increase of the reaction temperature from 25 °C up to 38 °C over a period of 15 min is observed. The reaction mixture is stirred for 20 min until TLC analysis reveals complete consumption of the starting material. The mixture is filtered through a Celite® pad and is washed with MTBE (250 mL). The filtrate is transferred to a 1-L separatory funnel, and the layers are separated. The aqueous layer is back-extracted with MTBE (125 mL) using a second 250-mL separatory funnel. The organic layers are consecutively washed with half-saturated aqueous NaHCO₃ solution (125 mL) and with brine (125 mL). The combined organic layers are then dried over MgSO₄ (3 g), filtered and concentrated (40 °C, 250 mmHg) to afford the title compound as yellow liquid (5.47 g, 32.3 mmol, 100%). Purification by Kugelrohr distillation (150 °C, 0.3 mmHg) gives the title compound as a colorless liquid (5.35 g, 31.6 mmol, 98%).