Methyl iodide → 3-ethyl-3,11-dihydro-9,11-dimethyl-6H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[4,3-d]-pyrimidin-6-one

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Reaction Steps

8.05 g. of 3-ethyl-3,11-dihydro-9-methyl-6H-pyrazolo[1,5-a]pyrazolo[4',3':5,6]pyrido[4,3-d]pyrimidin-6-one (0.03 mol.) are refluxed with stirring in 100 ml. of diethyleneglycol dimethylether together with 0.9 g. of sodium (0.04 mol.) for 2 hours. After this time, 14.2 g. of methyl iodide (0.1 mol.) are added and heating is continued for 12 hours. The solvent is removed in vacuo and the residue crystallized with methanol, filtered and washed with water to obtain 3-ethyl-3,11-dihydro-9,11-dimethyl-6H-pyrazolo[1,5-a]pyrazolo[4', 3':5,6]pyrido[4,3-d]-pyrimidin-6-one, yield 5.2 g. (61%), m.p. 306°-307° (methanol).

Provenance & Evidence