1,2,3,4-Tetraphenylcyclopenta-1,3-diene → HCID 86680257, compound

Participants

Reaction Conditions

Reaction Steps

Preparation analogous to N. Umeda et al., Angew. Chem. Int. Ed. 2008, 47, 4019: a solution of 25.2 g (100 mmol) of 2-(2-tert-butylpyrimidin-5-yl)benzimidazole (S48) and 110 mmol of the alkyne in 400 ml of DMF is initially introduced in a pressure Schlenk tube, 1.5 g (4 mmol) of tetraphenylcyclopentadiene, 547 mg (1 mmol) of pentamethylcyclopentadienyl-rhodium chloride dimer and 21.0 (105 mmol) of copper(II) acetate monohydrate are added, and the mixture is stirred in the sealed tube at 100° C. for 18 h. After cooling, the DMF is removed in vacuo, the residue is taken up in 1000 ml of THF and filtered through a short silica-gel column. After removal of the THF in vacuo, the oily residue is taken up in hot methanol (about 75 ml). After cooling, the crystals formed are filtered off with suction and recrystallised again from methanol with addition of a little ethyl acetate. The solids obtained in this way are freed from low-boiling components and non-volatile secondary components by sublimation (p about 1×10−5 mbar, T about 180-220° C.). Purity according to 1H-NMR typically >99.5%.

Provenance & Evidence