Triphenylphosphine → 3-Butyl-8-chloro-1-[4-(3-phenyl-5-isoxazolyl)butyl]-3,7-dihydro-1H-purine-2,6-dione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

3-Butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (100 mg, 0.354 mmol) and 4-(3-phenyl-5-isoxazolyl)-1-butanol (77 mg, 0.355 mmol) were dissolved in dry THF (4 ml) under nitrogen. A solution of dibenzyl azodicarboxylate (94%, 224 mg, 0.708 mmol) in dry THF (2 ml) was added. The mixture was cooled to 0° C. and a solution of triphenylphosphine (185 mg, 0.708 mmol) in dry THF (1 ml) was added. The mixture was stirred for 20 min at 0° C. then at room temperature overnight. The mixture was degassed then stirred with morpholine (0.308 ml) and tetrakis(triphenylphosphine)palladium(0) (82 mg) for 4.5 h. A further 60 mg of tetrakis(triphenylphosphine)palladium(0) was added and stirring continued overnight. The reaction was worked up by partition between EtOAc and 2M HCl, the organic phase evaporated and purified by aminopropyl SPE (5 g) washing with THF-MeOH (1:1), MeOH and eluting with DCM-MeOH (1:1) containing 5% AcOH. Further purification by MDAP afforded the title compound (56 mg).

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