反应详情

Sodium (1 mol) was dissolved in anhydrous ethanol (400 mL). To the obtained solution, Piperidine-1-carboxamidine (0.5 mol) was carefully added in portions. Then 4-(2-ethoxycarbonyl-acetyl)-piperidine-1-carboxylic acid tert-butyl ester (0.5 mol) was added dropwise, and the mixture was stirred at reflux for 4-6 h (monitored by TLC), cooled to room temperature, concentrated, diluted with water (300 mL) and acidified with acetic acid to pH-4. The formed precipitate was collected by filtration, washed with water and dried to afford 4-(6-hydroxy-2-piperidin-1-yl-pyrimidin-4-yl)-piperidine-1-carboxylic acid tert-butyl ester (89 g, 49%).

1. temperatureat reflux for 4-6 h (monitored by TLC)
2. concentrationconcentrated
3. additiondiluted with water (300 mL)
4. filtrationThe formed precipitate was collected by filtration
5. washwashed with water
6. customdried