Triphenylphosphine → 1,2,3,4-Tetrahydro-3-methyl-2,4-dioxo5-trimethylsilylethynyl-quinazoline

Participants

Reaction Conditions

Reaction Steps

To a degassed solution of 5-bromo-3-methyl-2,4-dioxo-1,2,3,4-tetrahydro-quinazoline (1.Og,4.Ommol) in 20 ml of DMF and 20 ml of triethylamine was added trimethylsilylacetylene (1.6ml,12mmol), 50mg of triphenylphosphine, 20mg of palladium(Il)acetate, and 1 mg of cuprous(I)iodide. The mixture was stirred under nitrogen, at 70° C.. After 7h additionally 0.4ml of trimethylsilylacetylene was added and hating continued for 4h. Then the mixture was evaporated in vacuo and the residue extracted with 100 ml of dichloromethane and 100 ml of water. The organic layer was washed twice with 100 ml of water dried over anhydrous sodium sulfate, treated with charcoal, filtered through a pad of celite, and evaporated. The residue was triturated with ether/petroleum ether (1:1) and filtered off and dried giving 0.50g (46%) of 1,2,3,4-tetrahydro-3-methyl-2,4-dioxo5-trimethylsilylethynyl-quinazoline.

Provenance & Evidence