1,4-Dichlorobenzene → N-Benzhydrylidene-N'-(4-chlorophenyl)hydrazine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

260 mL of 2-methyl-2-butanol are placed in a 500 mL round-bottomed flask, which is degassed with argon for 30 minutes. Once the degassing is complete, 60 mL of 2-methyl-2-butanol, palladium(II)diacetate (0.857 g, 1.27 mmol, 0.025 eq.) and the ligand MePHOS (0.928 g, 2.55 mmol, 0.05 eq.) are placed in a second dry round-bottomed flask under argon. The mixture is left stirring for 30 minutes at a temperature in the region of 25° C. Furthermore, 1,4-dichlorobenzene (7.49 g, 1 eq.) and sodium hydroxide powder (2.85 g, 1.4 eq.) are placed in the 500 mL round-bottomed flask. The catalyst is then transferred into the 500 mL round-bottomed flask, which is heated at a temperature in the region of 100° C. Finally, benzhydrylidenehydrazine (10 g, 50.9 mmol, 1 eq.) is added thereto. The resulting suspension is left stirring, and changes color quickly (dark red) until all of the halide has disappeared. The solvent is then evaporated to dryness and the residue is taken up in dichloromethane. The solid is filtered off through Celite® and then washed thoroughly with dichloromethane. The organic phase is washed with saturated ammonium chloride solution, dried over magnesium sulfate and then concentrated to dryness under vacuum. The residue is purified by chromatography on a column of silica gel, eluting at the start with an ethyl acetate/heptane mixture (10/90 by volume). N-Benzhydrylidene-N′-(4-chlorophenyl)hydrazine (85%) is thus obtained in the form of a yellow solid (Rf=0.35. EtOAc/Heptane 25/75 (v/v)).

Herkunft & Nachweise