Phenylboronic Acid → Benzophenone (6-chloropyrimidin-4-yl)hydrazone

Participants

Reaction Conditions

Reaction Steps

10.0 g (67.1 mmol) of 4,6-dichloropyrimidine, 14.5 g (73.8 mmol) of benzophenone hydrazone, 9.03 g (94.0 mmol) of sodium tert-butoxide, 409 mg (3.36 mmol) of phenylboronic acid, 301 mg (1.34 mmol) of palladium(II) acetate and 384 mg (1.34 mmol) of rac-2,2′-bis-(diphenylphosphino)-1,1′-binaphthalene are combined. The mixture is degassed and vented twice with argon, 400 ml of dry degassed toluene are added, the mixture is again degassed and vented twice with argon and heated at 90° C. overnight. After cooling, the reaction mixture is poured into water, the aqueous phase is extracted with ethyl acetate, the combined organic phases are concentrated and the residue is taken up in a mixture of dichloromethane and diethyl ether. The precipitate that remains is filtered off with suction (and discarded), the filtrate is concentrated and the residue is purified by column chromatography on silica gel 60 (mobile phase: toluene/ethyl acetate 8:2).

Provenance & Evidence