反应详情

A solution containing 11.2 g of this benzimidazolepropanoic acid (0.05 mole), diphenylphosphorylazide (14.0 g, 0.05 mole) and triethylamine (5.0 g, 0.0 mole) in 100 mL of t-butanol was heated at reflux for 10 hr. The volatile material was evaporated at 100° and 30 torr and the residue was diluted with ethanol-methylene chloride. Filtration of the chilled mixture provided a total of 6.5 g of 3,4-dihydro-3,3-dimethylpyrimido{1,6-a}benzimidazol-1(2H)-one as a white solid, m.p. 205°-210°. This material can be purified by reprecipitation from acid solution using 20% NaOH to afford white flakes, m.p. 211°-215°.

1. temperaturewas heated
2. temperatureat reflux for 10 hr
3. customThe volatile material was evaporated at 100°
4. addition30 torr and the residue was diluted with ethanol-methylene chloride
5. filtrationFiltration of the chilled mixture