Tetrahydrofuran → Pyrazolo(5,1-a)isoquinoline-1-methanol, 5,6-dihydro-2-phenyl-

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Reaction Steps

To 0.76 g. of LiAlH4 in 50 ml. of tetrahydrofuran, 6.08 g. of the methyl ester of 2-phenyl-5,6-dihydro-pyrazolo[5,1-a]isoquinoline-1-carboxylic acid dissolved in 75 ml. of tetrahydrofuran is added. The mixture is stirred for four hours at room temperature, then refluxed for one hour. To the reaction mixture at about 0° C. are subsequently added 0.76 ml. of water, 0.76 ml. of 20% NaOH and again 2.3 ml. of water. After addition of 75 ml. of ethyl ether, the inorganic precipitate is filtered off and the organic solution is evaporated to dryness to give 4 g. of the title product which, crystallized from ethanol, melts at 185°-7° C.

Provenance & Evidence