Triphenylphosphine → 6-methoxy-7-(2-(N-methyl-N-(t-butylcarbonyl)amino)ethoxy)-3-((pivaloyloxy)methyl)-3,4-dihydroquinazolin-4-one

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Reaction Steps

Diethyl azodicarboxylate (679 mg, 3.9 mmol) was added dropwise to a suspension of 7-hydroxy-6-methoxy-3-((pivaloyloxy)methyl)-3,4-dihydroquinazolin-4-one (918 mg, 3 mmol), triphenylphosphine (1 g, 3.9 mmol) and 2-(N-methyl-N-(t-butylcarbonyl)amino)ethanol (682 mg, 3.9 mmol), prepared as described below, in methylene chloride (20 ml) and the mixture stirred for 1 hour at ambient temperature. Further 2-(N-methyl-N-(t-butylcarbonyl)amino)ethanol (105 mg, 0.6 mmol), triphenylphosphine (786 mg, 3 mmol) and diethyl azodicarboxylate (522 mg, 3 mmol) were added and the mixture stirred for 30 minutes at ambient temperature. The mixture was concentrated to half volume by evaporation and purified by column chromatography eluting with methylene chloride/ether (7/3 increasing to 1/1) to give 6-methoxy-7-(2-(N-methyl-N-(t-butylcarbonyl)amino)ethoxy)-3-((pivaloyloxy)methyl)-3,4-dihydroquinazolin-4-one (1.3 g, 98%). 1H NMR Spectrum: (CDCl3) 1.2(s, 9H); 1.45(s, 9H); 3.05(br s, 3H); 3.72(br s, 2H); 3.98(s, 3H); 4.25(br s, 2H); 5.95(s, 2H); 7.1(br s, 1H); 7.6(s, 1H); 8.2(s, 1H)

Provenance & Evidence