Hydrazine hydrate (1:1) → (+/-)9-Amino-2-pyridin-4-yl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one
Reaction equation
[O:1]=[C:2]1[N:7]2[CH2:8][CH2:9][CH2:10][CH:11]([N:12]3C(=O)C4C(=CC=CC=4)C3=O)[C:6]2=[N:5][C:4]([C:23]2[CH:28]=[CH:27][N:26]=[CH:25][CH:24]=2)=[CH:3]1.O.NN>C(O)C>[NH2:12][CH:11]1[C:6]2=[N:5][C:4]([C:23]3[CH:28]=[CH:27][N:26]=[CH:25][CH:24]=3)=[CH:3][C:2](=[O:1])[N:7]2[CH2:8][CH2:9][CH2:10]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
To a solution of 3.2 g (8.59 mmol) of (+/−) 2-(4-oxo-2-pyridin-4-yl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-9-yl)-1H-isoindole-1,3(2H)-dione dissolved in 24 mL of ethanol was added 2.09 mL (43 mmol) of hydrazine hydrate and the resulting mixture was stirred under reflux for 2 hours. The mixture was filtered and the solid obtained was triturated with dichloromethane for 24 h, filtered, and the resulting filtrates were evaporated to dryness. The resulting residue was purified on silica gel eluting with a mixture of dichloromethane/methanol in the proportions 98/2 to 96/4 to give 1.37 g (66%) of the desired compound as a brown powder.