5-Aminomethyl-4-ethynyl-1,3-dimethylpyrazole

In 1973, the unexpected transformation of 4-chloroethynyl-l,3,5-trimethylpy-razole under the action of sodium amide in liquid ammonia into 5-aminomethyl-4-ethynyl-l,3-dimethylpyrazole in 85% yield was reported (73IZV2166). Within... 

Attempts were made to perform heterocyclization with 4-phenylethynyl- and 4-ethynyl-5-aminomethyl-l,3-dimethylpyrazole where, on the one side, a strained six-membered ring can be formed, and, on the other side, the aliphatic amino group is more nucleophilic than the aromatic (Scheme 112). However, all attempts to cyclize the ethynylpyrazole and its phenyl analog failed (86TH1). 

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