Triphenylphosphine → Ethyl {3-[3-(3-hydroxyphenyl)-6-oxo-6H-pyridazin-1-ylmethyl]phenyl}-carbamate

Participants

Reaction Conditions

Reaction Steps

17 g (56.2 mmol) of 6-[3-(tert-butyldimethylsilanyloxy)phenyl]-2H-pyridazin-3-one, 11 g (56.2 mmol) of ethyl (3-hydroxymethylphenyl)carbamate and 14.7 g (56 mmol) of triphenylphosphine are dissolved in 100 ml of DMF and 400 ml of THF. Under a nitrogen atmosphere, the yellow solution is cooled to 0° C., and 4.1 ml (26 mmol) of diethyl azodicarboxylate are slowly added dropwise, and the reaction mixture is stirred at room temperature for 20 h. The yellow suspension is evaporated to dryness. Water is added to the residue, which is then extracted with ethyl acetate, dried over sodium sulfate, and the solvent is distilled off. The residue is stirred for 15 h with isopropanol, the resultant precipitate is filtered off with suction and rinsed with isopropanol. The residue is dried in vacuo (6.8 g), 150 ml of THF are added, and 5 g (61 mmol) of tetramethylammonium fluoride are added. The mixture is stirred at room temperature overnight. The reaction mixture is evaporated. The residue is taken up in ethyl acetate, and water is added. A solid precipitates out, which is filtered off with suction and discarded. The organic phase is separated off from the aqueous phase. The organic phase is washed again with saturated sodium chloride solution, dried over sodium sulfate and evaporated to dryness.

Provenance & Evidence