Ethanol → 1-(5-chloro-2-pyridinyl)-4-methyl-4,5-dihydro-1H-pyrazol-3-amine

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Reaction Steps

As for Example 4 a 0.2 g. amount of sodium metal is dissolved in 50 ml. of absolute ethanol, then 5.0 g. of 5-chloro-2-hydrazinopyridine (Example 3) is added, followed by 4.8 g. of methacrylonitrile. The reaction mixture is refluxed for 18 hours. The solvent is removed in vacuo and water is added to give a gum which solidifies. The solid is collected by filtration, and washed with water. The solid is dissolved in dichloromethane, dried over magnesium sulfate and filtered through anhydrous magnesium silicate. The filtrate is evaporated and the residue is triturated with hexane to give a brown solid. The solid is dissolved in dichloromethane and hexane is added while concentrating to separate a solid. The mixture is cooled and filtered to give 3.4 g. of a gray solid. The desired product is recrystallized from dichloromethane-hexane to give a white solid, m.p. 159°-160° C.

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