反应详情

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%).

1. customprepared
2. stirringthe mixture stirred for 30 minutes at ambient temperature
3. concentrationThe mixture was concentrated to half volume by evaporation
4. custompurified by column chromatography
5. washeluting with methylene chloride/ether (7/3 increasing to 1/1)