Sodium Hydroxide → 2-(3,4-dichlorophenyl)-N-methyl-3,4-dihydropyrazol-5-amine

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Reaction Steps

To a stirred solution of 250 ml. of freshly distilled tetrahydrofuran under nitrogen is added cautiously 5.0 g. of lithium aluminum hydride, then 5.0 g. of N-[1-(3,4-dichlorophenyl)-3-pyrazolin-3-yl]formamide is added portionwise and the mixture is refluxed under nitrogen for 6 hours. The reaction mixture is cooled and the excess hydride is decomposed by the cautious dropwise addition of 5.0 ml. of water followed by 5.0 ml. of 15% sodium hydroxide solution and 15 ml. of water. The mixture is filtered and the filtrate is evaporated to give a gum and solid. This material is dissolved in dichloromethane and passed through a short column of a hydrous magnesium silicate. The effluent is evaporated to give a dark gum and solid. The mixture is dissolved in ether and treated as above with a hydrous magnesium silicate. The effluent is evaporated and the solid is recrystallized twice from ether-hexane to give 2.0 g. of the desired product as white crystals, m.p. 68°-70° C.

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